Tropical Medicine



Tetanus is an acute infectious disease of the central nervous system caused by clostridium tetani and is characterized by spasms of the skeletal muscles frequently attacking the muscles of the jaw. 

Tetanus is commonly known as ‘Lock-jaw.’

Cause of Tetanus

Tetanus is caused by the exotoxins of clostridium tetani.

  • The organism can live for a long time in any condition, especially dirty environments. So it can be found in dust, soil, or grass.
  • The clostridia can be normal organisms in the alimentary canal of animals but when passed out and gain entry to the human body, they become harmful. The organism can be found in cows, horse, sheep, or goat.

Incidence of tetanus:

  • In babies born at home before arrival at the hospital.
  • In homes where domestic animals are kept.
route of entry of tetanus

Pathophysiology of Tetanus

The pathophysiology of tetanus involves the invasion of the body by bacilli or spores, typically through deep puncture wounds or cuts. These bacilli find a suitable environment to multiply in anaerobic conditions. It is crucial to note that all unclean wounds pose a significant risk. Once the clostridium tetani organisms enter the wound, they unleash two forms of exotoxins into the surrounding tissues: tetanospasmin and tetanolysin.

Tetanospasmin, a potent toxin, plays a critical role in producing the disease’s clinical manifestations. It primarily affects the central nervous system (CNS). The toxins specifically target the motor nerve cells of the spinal cord and the brain. As a result, spasms develop in the muscles that are supplied by the corresponding nerves.

Route of entry

The route of entry for the clostridium tetani organisms includes various pathways, all of which can lead to infection and subsequent tetanus:

  1. Infected ulcerated wound.
  2. Postoperative wounds.
  3. Umbilical stumps (in newborns).
  4. Gun-shot wounds.
  5. Septic abortion.
  6. Jiggers or foreign bodies.
  7. Burns and scalds.

Signs and Symptoms

Tetanus manifests with a set of distinctive signs and symptoms, indicating the severity of the infection:

  1. Stiffness of the muscles, particularly noticeable in the jaw.
  2. Spasms affecting the muscles of the face, especially the cheek and jaw, leading to difficulty in opening the mouth, a condition referred to as trismus.
  3. The angles of the mouth are pulled outwards, causing a forced smile known as risus sardonicus or the “Devil’s grin.”
  4. The head is thrown back, and the back becomes arched due to the rigid muscles in the neck, a condition called opisthotonus.
  5. Signs of inflammation may be evident, such as swelling of the umbilical cord (if present in newborns), a wet cord, offensive smell, or pus discharge from the wound site.
  6. Patients may experience an elevated temperature and rapid pulse.
  7. Weight loss may occur due to difficulties in eating, leading to starvation.
  8. Spasms of the sphincters can result in retention of urine or stool, and in severe cases, sphincter rupture may occur.
  9. Swallowing becomes challenging as the muscles of the mouth and esophagus are affected by spasms.
  10. Spasms affecting the respiratory muscles may lead to prolonged periods without oxygen (anoxia), which can be life-threatening and result in death.
  11. Patients may have a wound or a history of a wound, which could be the point of entry for the tetanus-causing bacteria.

Alblett Classification of Tetanus

There are several grading systems; the scale proposed by Ablett5
is the most widely used . This categorizes patients
into four grades depending upon the intensity of spasms, and
respiratory and autonomic involvement.

Management of Tetanus

There’s no cure for tetanus. A tetanus infection requires emergency and long-term supportive care while the disease runs its course.

Aims of Management

  • To control spasms.
  • To eliminate the causative organism and its toxins.
  • To prevent complications, and ensure adequate nutrition for the patient. 

Specific treatment measures include:

  1. Penicillin: Administering penicillin is a crucial step in destroying the tetanus-causing organism.

  2. Anti-tetanus serum: The administration of anti-tetanus serum helps neutralize the spreading toxins and halt their further detrimental effects.

  3. Sedation and muscle relaxants: Medications like diazepam and chlorpromazine are given to provide sedation and muscle relaxation, effectively alleviating spasms and minimizing discomfort.

  4. Wound management: If there is a wound or focus of infection where the tetanus bacteria may have entered, the dead tissue is excised, and the area is irrigated with hydrogen peroxide. Leaving the wound open without suturing promotes oxygen exposure, hindering the growth of tetanus bacilli, which thrive in anaerobic conditions.

Control of spasms involves the following measures:

  • Absolute rest and isolation: The patient should be kept in a quiet room with dim lighting to minimize triggers for spasms.
  • Prevention of external stimuli: Measures such as fitting the door with suitable closing materials or springs prevent slamming noises that could stimulate the patient.
  • Warming hands before touching: Nurses should warm their hands before touching the patient to avoid any stimulation that might trigger spasms.
  • Medication administration: Sedatives and muscle relaxants, such as chlorpromazine (Largactil), and Diazepam, are given regularly through a nasogastric tube to maintain a controlled state and alleviate spasms.
  • o Example of 6 hourly regimen 







































General Management:

  1. Close observation and airway management: Monitor the patient closely, ensuring a clear airway and using a mucous extractor if necessary.

  2. Vital signs monitoring: Regularly check temperature, pulse, and respirations, noting the severity of the condition. Record the strength, frequency, duration, and body part involved in spasms using a spasm chart.

  3. Nutrition: Maintain adequate nutrition through nasogastric tube feeding to avoid stimulating spasms with injections. Prevent aspiration of fluids into the airway.

  4. Catheterization: Catheterize the patient to maintain proper bladder function.

  5. Fluid balance chart: Monitor and maintain fluid balance, initially using intravenous fluids if necessary and later transitioning to nasogastric tube feeding.

  6. Hygiene: Ensure daily cleaning of the cord with normal saline and perform oral care carefully. Turn the patient every two hours to prevent pressure sores.

  7. Vaccination: Prevent future tetanus cases by ensuring all individuals receive a full course of DPT (diphtheria, pertussis, and tetanus) vaccination.

  8. Use sterile equipment: Prevent cross-infection by using sterile equipment during medical procedures.

  9. Bowel and bladder care: Monitor and assist the patient in passing stool and urine.

  10. Medication: Administer prescribed drugs as instructed.

  11. Physiotherapy: Implement physiotherapy sessions for deep breathing exercises and active limb movements.


  1. Public health education: Raise awareness about the dangers of using unsterilized equipment during childbirth and applying native medicine or other substances to the umbilical cord.

  2. Immunization: Ensure that all women of childbearing age are vaccinated against tetanus.

  3. Safe childbirth practices: Promote safe and clean practices during childbirth to prevent infections.

  4. Discourage harmful practices: Discourage practices like applying cow dung to a child’s umbilical cord.

  5. Wound care education: Educate people on cleaning wounds thoroughly with water and soap to prevent infections. Encourage covering wounds with sterile dressings and seeking early medical attention for cut wounds.

  6. Protective gear: Encourage the use of gum boots when digging to prevent soil-related infections.

Complications of Tetanus

  1. Fracture of bones or the spine: The intense and frequent muscle spasms can cause fractures in bones or the spine, especially if the spasms are severe and uncontrolled.

  2. Pneumonia: Heavy sedation, a common treatment for managing tetanus spasms, may lead to shallow breathing or difficulty in clearing the airway, increasing the risk of pneumonia, a potentially severe respiratory infection.

  3. Brain damage: The potent toxins produced by the tetanus-causing bacteria can affect the central nervous system, leading to brain damage in severe cases.

  4. Growth retardation: In children affected by tetanus, the disease can interfere with proper nutrition and growth, potentially causing growth retardation.

  5. Exhaustion: The continuous and strenuous muscle spasms can lead to extreme exhaustion, further weakening the patient’s overall condition.

  6. Respiratory failure: In severe cases, the spasms can affect the respiratory muscles, resulting in respiratory failure, where the patient is unable to breathe adequately on their own.

  7. Retention of urine: Spasms in the pelvic region can cause the sphincters to contract, leading to difficulty in passing urine and possible urine retention.

  8. Death due to airway obstruction: In the most severe cases, the intense spasms, particularly those affecting the muscles of the jaw and neck, can obstruct the airway, leading to suffocation and potential death.

Test Questions

Which bacterium causes tetanus?
a) Streptococcus pyogenes
b) Staphylococcus aureus
c) Clostridium tetani
d) Escherichia coli
Answer: c) Clostridium tetani

Explanation: Clostridium tetani is the bacterium responsible for causing tetanus.

What is the common term used to describe tetanus due to spasms in the jaw muscles?
a) Trismus
b) Opisthotonus
c) Risus sardonicus
d) Tetanospasmin
Answer: a) Trismus

Explanation: Trismus is the medical term for difficulty in opening the mouth due to jaw muscle spasms, which is commonly known as “Lock-jaw.”

What is the primary goal of managing tetanus?
a) Preventing complications
b) Destroying the toxin
c) Controlling fever
d) Alleviating pain
Answer: a) Preventing complications

Explanation: The main aim of managing tetanus is to prevent complications associated with the disease and ensure the best possible outcome for the patient.

What is the specific treatment given to destroy the tetanus-causing organism?
a) Penicillin
b) Paracetamol
c) Aspirin
d) Ibuprofen
Answer: a) Penicillin

Explanation: Penicillin is administered to destroy the Clostridium tetani bacterium responsible for causing tetanus.

Which complication of tetanus can lead to respiratory failure?
a) Pneumonia
b) Fracture of bones
c) Brain damage
d) Respiratory muscle spasms
Answer: d) Respiratory muscle spasms

Explanation: Tetanus-induced spasms affecting the respiratory muscles can lead to respiratory failure, where the patient is unable to breathe adequately on their own.

Why is the use of a mucous extractor important in tetanus management?
a) To prevent dehydration
b) To clear the airway
c) To alleviate muscle spasms
d) To prevent fever
Answer: b) To clear the airway

Explanation: A mucous extractor is used to clear the airway and prevent obstruction caused by excessive secretions, which is crucial in tetanus management.

What is the recommended method for feeding tetanus patients to avoid spasms triggered by injections?
a) Intravenous feeding
b) Nasogastric tube feeding
c) Oral feeding
d) Intramuscular injections
Answer: b) Nasogastric tube feeding

Explanation: Nasogastric tube feeding is used to provide nutrition and administer drugs to tetanus patients while avoiding the stimulation of spasms caused by intramuscular injections.

Which immunization should be given to prevent future tetanus cases?
a) Hepatitis B
b) Measles, Mumps, and Rubella (MMR)
c) Diphtheria, Pertussis, and Tetanus (DPT)
d) Polio
Answer: c) Diphtheria, Pertussis, and Tetanus (DPT)

Explanation: The DPT vaccine provides immunity against diphtheria, pertussis (whooping cough), and tetanus, preventing future tetanus cases.

What measure can be taken to prevent tetanus in newborns with umbilical stumps?
a) Cleaning the stump with cow dung
b) Applying native medicine on the stump
c) Keeping the stump dry and clean
d) Ignoring the stump until it falls off naturally
Answer: c) Keeping the stump dry and clean

Explanation: Maintaining cleanliness and dryness of the umbilical stump can prevent infection and the risk of tetanus in newborns.

What is the purpose of physiotherapy in tetanus management?
a) To provide pain relief
b) To promote muscle strength
c) To control spasms
d) To increase body temperature
Answer: b) To promote muscle strength

Explanation: Physiotherapy aims to promote muscle strength and mobility, which can be helpful in the recovery process of tetanus patients.

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Leprosy, also known as Hansen’s disease, is a chronic infection caused by the bacteria Mycobacterium leprae and Mycobacterium lepromatosis. 

It primarily affects the skin and peripheral nerves.

Cause of Leprosy

 Leprosy is caused by Mycobacterium leprae and Mycobacterium lepromatosis. M. lepromatosis is a relatively newly identified mycobacterium isolated from a fatal case of diffuse lepromatous leprosy in 2008.

Transmission of Leprosy

  •  Nasal route via secretions 
  •  Transplacental and breast feeding 
  •  Genetic predisposition
Types of leprosy

Types of Leprosy:

  1. Lepromatous leprosy (90%): This is the most common type of leprosy, accounting for about 90% of cases. It is characterized by widespread skin lesions and a weak cellular immune response. The bacteria multiply profusely in the body, leading to severe skin and nerve damage.

  2. Tuberculoid leprosy: In this type, the immune response is stronger, and the skin lesions are few and well-defined. The affected areas may have a loss of sensation, but nerve damage is less severe compared to lepromatous leprosy.

  3. Borderline leprosy: Borderline leprosy lies in between lepromatous and tuberculoid leprosy in terms of immune response and clinical features. It displays mixed characteristics, with moderate skin lesions and nerve involvement.

  4. Undeterminate (Dismorphoid or Undetermined) leprosy: This type is diagnosed when the symptoms and immune response are not well-defined, making it difficult to classify precisely. It often occurs early in the disease’s progression and may eventually develop into one of the other types.

Differences between Tuberculoid, Lepromatous and Borderline leprosy 

Cutaneous lesion 




Characteristic number of lesions 




Size of lesion 



Both – large & small

Symmetry of lesions 




Surface of lesions 

Rough and scaly 


Rough & scaly





Incubation Period: 

The incubation period of leprosy refers to the time between when a person is exposed to the bacteria Mycobacterium leprae and the onset of symptoms. In leprosy, this period usually lasts from 2 to 5 years. However, in certain cases, especially in lepromatous leprosy, the incubation period may extend to a longer duration, lasting 8 to 12 years before signs of the disease become apparent.

Signs and Symptoms:

 Leprosy presents with a variety of signs and symptoms, which may vary depending on the type and stage of the disease. Some common manifestations include:

  • Anaesthetic skin lesions: These are patches of skin that lose their ability to feel sensation. Individuals may not be able to detect pain, heat, or touch in these areas, making them prone to injuries.

  • Thickened peripheral nerves: Leprosy can affect the peripheral nerves, leading to their thickening and enlargement, often seen as lumps under the skin.

  • Nasal stuffiness: In some cases, leprosy can cause inflammation and swelling in the nasal passages, leading to nasal stuffiness and congestion.

  • Saddled nose (Saddle nose): This refers to the collapse of the nasal bridge due to the destruction of the nasal septum, which can occur in advanced cases of leprosy.

  • Loss of eyebrows and lashes: Leprosy can cause the loss of eyebrows and eyelashes, leading to changes in facial appearance.

  • Erythema nodosum: This is a condition characterized by painful, red nodules that can occur on the skin or under the skin’s surface.

  • Inflammatory eye changes: Leprosy may affect the eyes, leading to various eye problems, including inflammation and potential vision impairment.


To diagnose leprosy and confirm the presence of Mycobacterium leprae, healthcare professionals may conduct several investigations, such as:

  • Histamine test: This test helps assess the level of nerve damage by evaluating the body’s response to histamine injection.

  • Lepromine test: Lepromine is a substance derived from the leprosy bacteria. The test measures the immune response to lepromine to determine the type of leprosy and the individual’s immune status.

  • Polymerase Chain Reaction (PCR): PCR is a molecular technique used to detect the genetic material of the bacteria in skin samples, aiding in early and accurate diagnosis.

  • Skin snip for Mycobacterium leprae (modified ZN): A small sample of skin is taken and stained using the modified Ziehl-Neelsen method to visualize the presence of Mycobacterium leprae under a microscope.

Treatment for Leprosy:

  1. Tuberculoid leprosy:

    • Dapsone + Rifampicin
  2. Lepromatous leprosy:

    • Dapsone + Rifampicin + Clofazimine
  3. Borderline leprosy:

    • Dapsone
Non-leprosy drugs used in the management of leprosy:
  • Steroids
  • Vitamin B complex

Drugs for leprosy are commonly administered in fixed drug combinations known as MDT (Multi-Drug Therapy). MDT has been a highly effective approach in treating leprosy and preventing the development of drug resistance.

Complications of leprosy include:

  • Madorosis (loss of eyebrows and eyelashes)
  • Nasal bridge collapse
  • Ocular complications: corneal ulcer, blindness
  • Leonine faces (thickened, lion-like appearance of facial skin)
  • Loss of sensation to heat, pain, and light touch
  • Multiple ulcerations due to nerve damage and loss of sensation
  • Nerve enlargement
  • Orchitis (inflammation of the testicles)
  • Disuse of some parts of the body
  • Contractures and shortening of phalanges, especially the 4th and 5th fingers and toes
  • Elongated soft ear lobes
  • Sterility in men secondary to orchitis
  • Hammer toes (abnormal bending of the toes)
  • Reactional states secondary to successful drug therapy (erythema nodosum leprosum).

Test Questions

Question: Leprosy primarily affects which body parts?
a) Liver and kidneys
b) Skin and peripheral nerves
c) Lungs and heart
d) Brain and spinal cord
Answer: b) Skin and peripheral nerves
Explanation: Leprosy is a chronic infection that primarily affects the skin and peripheral nerves.

Question: What is the incubation period for lepromatous leprosy?
a) 1-2 years
b) 3-5 years
c) 6-8 years
d) 8-12 years
Answer: d) 8-12 years
Explanation: Lepromatous leprosy has a longer incubation period of 8-12 years, compared to other types of leprosy.

Question: Which type of leprosy has well-defined, few skin lesions and less severe nerve damage?
a) Tuberculoid leprosy
b) Lepromatous leprosy
c) Borderline leprosy
d) Indeterminate leprosy
Answer: a) Tuberculoid leprosy
Explanation: Tuberculoid leprosy is characterized by well-defined, few skin lesions and less severe nerve damage.

Question: Which drug combination is used to treat lepromatous leprosy?
a) Dapsone
b) Dapsone + Rifampicin
c) Dapsone + Rifampicin + Clofazimine
d) Rifampicin
Answer: c) Dapsone + Rifampicin + Clofazimine
Explanation: Lepromatous leprosy is treated with a combination of Dapsone, Rifampicin, and Clofazimine.

Question: What are the complications of leprosy that may lead to blindness?
a) Loss of eyebrows and lashes
b) Nasal bridge collapse
c) Corneal ulcer
d) Erythema nodosum leprosum
Answer: c) Corneal ulcer
Explanation: Leprosy can cause corneal ulcers, which may lead to blindness if left untreated.

Question: Which investigation helps diagnose leprosy by detecting Mycobacterium leprae in skin samples?
a) Lepromine test
b) Histamine test
c) PCR
d) Skin snip for Mycobacterium leprae (modified ZN)
Answer: d) Skin snip for Mycobacterium leprae (modified ZN)
Explanation: Skin snip test with modified Ziehl-Neelsen staining is used to visualize Mycobacterium leprae under a microscope.

Question: What is the most common type of leprosy?
a) Tuberculoid leprosy
b) Lepromatous leprosy
c) Borderline leprosy
d) Indeterminate leprosy
Answer: b) Lepromatous leprosy
Explanation: Lepromatous leprosy is the most common type, accounting for about 90% of leprosy cases.

Question: Which type of leprosy has a weak cellular immune response and widespread skin lesions?
a) Tuberculoid leprosy
b) Lepromatous leprosy
c) Borderline leprosy
d) Indeterminate leprosy
Answer: b) Lepromatous leprosy
Explanation: Lepromatous leprosy is characterized by a weak cellular immune response and widespread skin lesions.

Question: What is the term used to describe the thickened, lion-like appearance of facial skin in leprosy?
a) Madorosis
b) Leonine faces
c) Erythema nodosum
d) Nasal bridge collapse
Answer: b) Leonine faces
Explanation: Leonine faces refer to the thickened, lion-like appearance of facial skin seen in some cases of leprosy.

Question: Which non-leprosy drug is commonly used in the management of leprosy?
a) Antibiotics
b) Steroids
c) Antifungals
d) Antivirals
Answer: b) Steroids
Explanation: Steroids are used in the management of leprosy to control inflammation and reduce immune reactions in some cases.


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Tuberculosis, commonly known as TB (short for tubercle bacillus), is a widespread and often deadly infectious disease caused by various strains of mycobacteria.

While primarily affecting the lungs, it can also impact other parts of the body. Around one-third of the world’s population (1 in 3 or 3 out of 10 people) is affected by this condition. Individuals with HIV/AIDS have a higher risk of contracting tuberculosis.


The disease is caused by mycobacterium tuberculosis, which is a small, aerobic, non-motile bacillus.

Mode of Spread

TB spreads through the air when individuals with an active infection cough, sneeze, or transmit respiratory fluids. Additionally, it can spread through the blood (haematogenous spread).

Types of Tuberculosis

Types of Tuberculosis

  • Pulmonary tuberculosis.
  • Extra-pulmonary tuberculosis.
  • Primary and Secondary tuberculosis.

Clinical Features:

Pulmonary TB:

  • Fever and chills
  • Night sweats
  • Loss of appetite
  • Weight loss
  • Easy fatigability
  • Persistent cough lasting more than 3 weeks, with or without haemoptysis (coughing up blood)
  • Significant finger clubbing (abnormal swelling of the fingertips)
  • Chest pain
  • Productive cough or non-productive cough in smear-negative TB
  • Lymphadenopathy (swollen lymph nodes)

Extrapulmonary TB:

In approximately 15-20% of active TB cases, the infection spreads beyond the lungs, resulting in various forms of extrapulmonary tuberculosis. This type is more common in individuals with weakened immune systems and young children. In people with HIV, extrapulmonary TB occurs in more than 50% of cases.

Notable sites of extrapulmonary infection include:

  • The pleura, leading to tuberculous pleurisy.
  • The central nervous system, causing tuberculous meningitis.
  • The lymphatic system, resulting in TB lymph nodes.
  • The genitourinary system, causing urogenital tuberculosis.
  • The bones and joints, leading to Pott’s disease of the spine. When it affects the bones, it is known as “osseous tuberculosis,” a form of osteomyelitis.
  • Sometimes, a tubercular abscess may burst through the skin, resulting in a tuberculous ulcer. Ulcers originating from infected lymph nodes nearby are typically painless.
  • A potentially severe and widespread form of TB is “disseminated” TB, commonly known as miliary tuberculosis. Miliary TB accounts for about 10% of extrapulmonary cases.

Risk factors

Several factors increase the susceptibility of individuals to TB infections:

  • HIV infection is a significant global risk factor, contributing to 13% of all TB cases.
  • Tuberculosis is closely associated with overcrowding and malnutrition, making it a prevalent disease in impoverished communities.
  • Inhabitants and employees of places where vulnerable individuals gather, such as prisons and homeless shelters, face higher risks.
  • Medically underserved and resource-poor communities, as well as high-risk ethnic minorities, are more susceptible.
  • Children in close contact with high-risk patients are at increased risk.
  • Health care providers serving TB patients are also at higher risk.
  • Chronic lung disease is another significant risk factor.
  • Smokers have nearly double the risk of TB compared to nonsmokers.
  • Other conditions like alcoholism and diabetes mellitus can also elevate the risk of developing tuberculosis.


  • Approximately one-third of the world’s population is infected with tuberculosis.
  • TB causes 25% of preventable adult deaths, and three-fourths of these affected individuals are in their productive age.
  • South Eastern Asia has the highest number of TB cases.
  • Africa has the world’s highest incidence rate, with an annual incidence rate of 345 cases per 100,000 people.
  • The infection rate is higher in men than in women.
Primary Tuberculosis:
  • It occurs in individuals who have never been exposed to tubercle bacilli before.
  • Tubercle bacilli are inhaled and reach the lungs, where they multiply and can spread to the hilar lymph nodes through the lymphatic system and blood.
  • Approximately six weeks after the primary infection, the body’s immune response kicks in, preventing further multiplication of the tubercle bacilli.
  • Some bacilli may die, and the remaining ones are walled off by immune cells called epithelioid cells, forming a ghon focus. This ghon focus can persist for years in primary tuberculosis.
  • The ghon focus and hilar lymphadenopathy together form a primary complex in primary tuberculosis.
  • Only about 10% of those with primary infection progress to develop tuberculosis disease.
ghon focus
Ghon focus
Secondary Tuberculosis:
  • This type of tuberculosis can result from either the reactivation of tubercle bacilli acquired during primary infection or reinfection by tubercle bacilli in a person previously exposed to the organisms.


  • TB infection starts when mycobacteria reach the pulmonary alveoli and invade and replicate there.
  • In addition to the lungs, tuberculosis can spread through the bloodstream, leading to infection in distant sites like peripheral lymph nodes, kidneys, brain, and bones.
  • The infection triggers an inflammatory response, resulting in the formation of granulomas. Granulomas are collections of activated macrophages, T lymphocytes, B lymphocytes, and fibroblasts.
  • The tubercle bacilli are surrounded by lymphocytes, forming a peripheral rim and creating a Ghon focus. (see image below)
  • Inside the granulomas, the bacteria can become dormant, causing latent infection. Caseation, a type of abnormal cell death, occurs in the center of the tubercles.
  • In severe cases, where TB bacteria enter the bloodstream from damaged tissue, multiple foci of infection can develop throughout the body, appearing as tiny white tubercles in the tissues. This condition is known as miliary tuberculosis and is more common in young children and individuals with HIV.
  • Tissue destruction and necrosis are balanced by healing and fibrosis. Scarring and cavities filled with caseous necrotic material replace affected tissue.

Diagnosis (Investigations):

When tuberculosis is suspected, the following investigations can aid in confirming the diagnosis:

  1. Signs of lung disease or constitutional symptoms lasting longer than two weeks.
  2. Chest X-ray: Imaging the chest can reveal characteristic abnormalities, such as infiltrates, cavities, or nodules, which can indicate tuberculosis.
  3. Multiple sputum cultures for acid-fast bacilli (AFB): Sputum samples are collected at different times, typically spot samples and early morning samples, to increase the chances of detecting the tuberculosis bacteria.
  4. Tuberculin skin tests: Also known as the Mantoux or Heaf test, it is commonly used to assess TB infection in children and identify individuals at risk of developing tuberculosis.
  5. Haematological tests:
    • Full blood cell count (FBC): This test helps evaluate any abnormalities in blood cell counts that may be indicative of an infection or inflammation.
    • Erythrocyte Sedimentation Rate (ESR): An elevated ESR can raise suspicion of tuberculosis, as it indicates inflammation in the body.
  6. Tissue biopsy: In cases where tuberculosis affects extrapulmonary sites or when other tests are inconclusive, a biopsy of the affected tissue may be performed to examine the presence of tubercle bacilli.

Relationship between HIV and TB:

Effects of HIV on TB:
  1. Development of active TB: Individuals infected with HIV have a higher risk of developing active tuberculosis once exposed to the TB bacteria.
  2. High risk of re-infection: HIV-positive individuals are more susceptible to being infected with a second strain of TB after already having the infection.
  3. Increased incidence of TB: The overall incidence of tuberculosis increases due to the higher prevalence of HIV, which weakens the immune system and makes individuals more susceptible to TB.
  4. Changes in TB presentation: TB in HIV-positive individuals may present with clinical and bacteriological changes, such as a non-productive cough, absence of hemoptysis (coughing up blood), and a miliary pattern on imaging instead of cavitations.
  5. Quicker development of TB complications: HIV accelerates the progression of TB and its associated complications.
Effects of TB on HIV:
  1. Increased HIV replication: TB infection can enhance the replication of HIV, leading to a higher viral load and faster progression to AIDS.
  2. Common opportunistic infection: TB is one of the most common opportunistic infections in individuals living with HIV and is a leading cause of death in this population.
  3. Interference with ARV treatment: Some anti-TB medications, such as Rifampicin, can interfere with certain antiretroviral drugs (ARVs), like Nevirapine and protease inhibitors, necessitating adjustments in treatment.

Consequences of dual infection with HIV and TB:

  • Increased morbidity and mortality.
  • Higher recurrence rate of TB after completing treatment.
  • Drug resistance leading to multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB).
  • Higher rates of treatment non-adherence due to overlapping medication regimens.
  • Increased risk of drug toxicity from the combined treatment.

Management of HIV and TB co-infection:

  • Prioritize TB treatment before starting ARVs.
  • Start ARVs if CD4 count is below 350 cells/mm³, either after finishing TB treatment or during the intensive phase, depending on the clinical situation.
  • Consider drug interactions between TB and HIV regimens when selecting medications.
  • Use directly observed therapy (DOTs) for TB treatment and closely monitor patients for toxicity and adherence.
  • Administer prophylaxis for opportunistic infections as indicated.

Complications of TB:

  • Pleural effusion: Accumulation of fluid in the pleural space of the lungs.
  • Pericardial effusion: Accumulation of fluid around the heart.
  • Empyema: Pus-filled cavity in the pleural space.
  • Pneumothorax: Presence of air or gas in the pleural cavity, causing lung collapse.
  • Lung fibrosis: Scarring of lung tissue, leading to impaired lung function.
  • Lung collapse: Collapse of a lung or part of a lung due to blockage or compression.
  • Extra-pulmonary TB: TB affecting organs other than the lungs, such as TB meningitis.

Treatment of TB:

Aims of TB Treatment:

  • To cure the patient of tuberculosis.
  • To prevent complications and death from TB.
  • To reduce the transmission of TB to others.

Case Definitions:

  1. New Case: A person who has never received TB treatment or has taken TB treatment for four weeks or less.
  2. Relapse: A patient who was previously diagnosed with TB, completed the course of anti-TB drugs, was declared cured, but has now become smear positive again.
  3. Failure: A person who continues to be smear positive at five months, despite adequately taking anti-TB drugs, or who was smear negative and becomes smear positive at two months.
  4. Defaulter: A patient who starts taking anti-TB drugs for more than four weeks but interrupts treatment (stops taking the drugs) for four weeks or more.
Drugs Used in TB Treatment:
  1. Rifampicin (R)
  2. Isoniazid (H or INH)
  3. Ethambutol (E)
  4. Pyrazinamide (Z)
  5. Streptomycin (S)
Standard TB Treatment Regimen: 

The World Health Organization (WHO) recommends a standard six-month treatment regimen for drug-sensitive TB cases, which typically includes the following four drugs for the first two months:

  1. Rifampicin (R)
  2. Isoniazid (H)
  3. Pyrazinamide (Z)
  4. Ethambutol (E)

This initial phase is followed by a continuation phase for the next four months, during which the drugs used may vary depending on the patient’s response to treatment and drug sensitivity testing.

It’s important to note that TB treatment should be administered under direct observation (DOTs) whenever possible to ensure proper adherence and to prevent the development of drug-resistant TB strains. Check DOT below in details.

Treatment regimen 

 Short course TB treatment regimen

Patient category (type of TB) 

Initial phase 

Continuation phase

1. New smear positive 

2. New smear negative 

3. Severe extra-pulmonary



4. Previously treated smear  POSITIVE: 


Failure to respond 

Return after interruption



5. Any form of TB in children

6. Adult non-severe extra pulmonary



Non-anti-TB Drugs Used in TB:
  1. Pyridoxine (Vitamin B₆): Administered to prevent or treat peripheral neuropathy, a side effect of Isoniazid (H) used in TB treatment. Pyridoxine supplementation helps prevent nerve damage caused by Isoniazid.

  2. Steroids: Used as adjunct therapy in specific forms of TB to reduce inflammation and improve outcomes. Steroids are commonly used in the treatment of:

    • TB Meningitis
    • TB Pericarditis
    • TB of Adrenals
DOTS (Directly Observed Therapy Short course):

How it works:

  • DOTS is a community-based TB care approach adopted by countries to improve TB treatment outcomes.
  • Trained workers or treatment supporters ensure that patients take their daily treatment doses and record the administration on the TB card.
  • DOTS is the standard of care for all TB cases and suspects.
  • It helps decrease relapse, defaulter rates, and the development of acquired drug resistance.
  • When combined with other measures, DOTS promotes treatment adherence.
  • After diagnosing TB and initiating treatment, the diagnostic center records the information in the health unit’s TB register.
  • The sub-county health worker transfers this information to the sub-county health worker register and identifies a treatment supporter in the patient’s village.
  • The treatment supporter is trained to observe the patient taking their treatment, record it on the TB card, keep the drugs, and remind the patient of follow-up assessments at the health unit at 2 months, 5 months, and 8 months.
  • The sub-county health worker collects medication from the health unit and delivers it to the treatment supporter.

Prevention of TB:

  • Early detection and proper management of TB cases.
  • Early case findings to identify and treat TB cases promptly.
  • Health education to raise awareness about TB transmission and prevention.
  • Training of all health workers to recognize early signs of TB.
  • Vaccination of children with the Bacille Calmette-Guérin (BCG) vaccine to protect against severe forms of TB in childhood.
  • Prophylaxis with Isoniazid for individuals at high risk of developing TB, such as those with latent TB infection or individuals with HIV.
  • Prevention and management of medical conditions like HIV, which increase the risk of TB.
  • Implementation of the DOTS program to improve treatment adherence and outcomes.
midwives revision in exams question approach for nursing and midwifery exams uganda

Test Questions

Question: Which bacterium is responsible for causing tuberculosis?

a) Streptococcus pneumoniae
b) Mycobacterium tuberculosis
c) Escherichia coli
d) Staphylococcus aureus

Answer: b) Mycobacterium tuberculosis
Explanation: Mycobacterium tuberculosis is the specific bacterium that causes tuberculosis.

Question: What is the most common site of TB infection in the human body?
a) Liver
b) Lungs
c) Heart
d) Kidneys

Answer: b) Lungs
Explanation: Pulmonary tuberculosis is the most common form of TB, affecting the lungs.

Question: In HIV-positive individuals, the risk of developing active tuberculosis:
a) Decreases
b) Stays the same
c) Increases
d) Remains unaffected

Answer: c) Increases
Explanation: HIV weakens the immune system, making individuals more susceptible to developing active tuberculosis once infected with Mycobacterium tuberculosis.

Question: Which of the following is NOT a clinical feature of pulmonary tuberculosis?
a) Fever and chills
b) Night sweats
c) Loss of appetite
d) Severe abdominal pain

Answer: d) Severe abdominal pain
Explanation: Severe abdominal pain is not a typical clinical feature of pulmonary tuberculosis.

Question: What is the standard duration of treatment for drug-sensitive tuberculosis?
a) 3 months
b) 6 months
c) 9 months
d) 12 months

Answer: b) 6 months
Explanation: The standard treatment regimen for drug-sensitive TB lasts for 6 months.

Question: In which form of TB, patients may present with a non-productive cough and a miliary pattern on imaging?
a) Drug-resistant TB
b) Extrapulmonary TB
c) Latent TB
d) Multidrug-resistant TB

Answer: b) Extrapulmonary TB
Explanation: Extrapulmonary TB can present with atypical symptoms like a non-productive cough and a miliary pattern on imaging.

Question: What is the main purpose of the DOTS program in TB management?
a) To prevent TB transmission
b) To promote TB vaccination
c) To monitor drug resistance
d) To improve treatment adherence

Answer: d) To improve treatment adherence
Explanation: The main aim of the DOTS program is to ensure that patients adhere to their TB treatment, which leads to better outcomes and reduced relapse rates.

Question: Which non-anti-TB drug is used to prevent or treat peripheral neuropathy, a side effect of Isoniazid?
a) Vitamin C
b) Vitamin D
c) Pyridoxine (Vitamin B₆)
d) Folic acid

Answer: c) Pyridoxine (Vitamin B₆)
Explanation: Pyridoxine is used to prevent or treat peripheral neuropathy caused by Isoniazid.

Question: TB Meningitis is best managed with the addition of which adjunct therapy?
a) Antibiotics
b) Antifungals
c) Antivirals
d) Steroids

Answer: d) Steroids
Explanation: TB Meningitis is often treated with the addition of steroids to reduce inflammation and improve outcomes.

Question: What is the primary aim of TB prevention?
a) Eradicate Mycobacterium tuberculosis from the environment
b) Reduce the incidence of drug-resistant TB
c) Prevent the transmission of TB from person to person
d) Increase vaccination coverage in high-risk populations

Answer: c) Prevent the transmission of TB from person to person
Explanation: The primary aim of TB prevention is to break the chain of transmission by preventing the spread of Mycobacterium tuberculosis from infected individuals to others.

Tuberculosis Read More »



Measles, also known as Morbilli, is a highly contagious acute infection of the respiratory system caused by the morbillivirus. 

It is characterized by a widespread skin rash, fever, and inflammation of the mucous membranes.

The transmission of measles occurs through respiration, mainly by coming into contact with fluids from the nose and mouth of an infected person. Due to its high contagion, it can easily spread among individuals.

The incubation period for measles typically lasts from 9 to 12 days.

 Risk Factors

Several risk factors increase the likelihood of contracting measles, including:

  1. Immunodeficiency in children.
  2. Traveling to regions where measles is common or having contact with individuals who have visited these areas.
  3. Malnutrition, which can weaken the immune system.
  4. Pregnancy, as it may increase susceptibility to the virus.
  5. Vitamin A deficiency, which can compromise the body’s ability to fight infections.
Signs and symptoms of measles

Signs and symptoms of measles/Stages

Measles, an acute and highly communicable infection caused by the morbillivirus, presents a clinical picture that can be divided into three distinct stages: prodromal, eruptive, and convalescent. Suspecting measles becomes crucial when patients exhibit the classic triad of the three “Cs”: cough, conjunctivitis, and coryza.

Stage 1: Prodromal Stage

  • The incubation period lasts approximately 10-14 days.
  • Patients may not show any signs or symptoms during this stage.
  • Abrupt onset of mild to moderate symptoms, characterized by:
    • Fever
    • Headache
    • General malaise
    • Loss of appetite (anorexia)
    • Enlarged neck lymph nodes
    • Abdominal pain
    • Diarrhea
    • Vomiting

Stage 2: Eruptive Stage

  • Abrupt onset with severe symptoms, including:
    • Very high fever
    • Cough
    • Photophobia (sensitivity to light)
    • Red eyes and conjunctivitis
    • Hoarseness of the voice
    • Distinctive Koplik spots on the mucous membrane of the mouth, next to the molar teeth. These spots may disappear once the rash appears.
  • Temperature rises on the first day (37.8-39.4 degrees Celsius), may slightly fall on the third day, then rise again on the fourth day with the onset of the rash.
  • The rash appears around the fourth day and starts on the forehead, behind the ears, neck, and then spreads over the face and entire body. The rash is a red maculo-papular eruption, giving the face a bloated, swollen appearance.

Stage 3: Convalescent Stage

  • Improvement and disappearance of signs and symptoms begin.
  • Key features include:
    • Desquamation of the skin (shedding of the rash)
    • A decline in body temperature
    • Resolution of hoarseness of the voice
    • Weight gain as the patient’s condition improves.

Nursing Care/Management for a Patient within 72 Hours of Measles:

Aims of Care/Management:

  1. To reduce body temperature.
  2. To correct dehydration.
  3. To prevent further complications.


  1. Admit the child to a well-ventilated room in an isolation unit in the children’s ward.
  2. Record the patient’s particulars, including name, age, next of kin, and full address on the admission forms.
  3. Reassure the mother/caregiver about the child’s condition.


  1. Monitor vital signs (Temperature, pulse, respiration, blood pressure, and weight) and record them in an observation chart for baseline monitoring.
  2. Conduct a comprehensive head-to-toe assessment to identify any abnormalities such as jaundice, edema, dehydration, cyanosis, anemia, and lymphadenopathy. Document findings in the patient file.
  3. Inform the doctor about the patient’s condition and prepare for any required investigations and medical treatments.
  4. Carry out procedures, such as tepid sponging, based on the patient’s findings (e.g., in case of high fever).
  1. Conduct necessary investigations to rule out other diseases, such as:
    • Blood slide for malaria parasites
    • Full blood count (FBC) to rule out other infections
    • Urinalysis
    • Salivary measles-specific IgA testing (rarely done).
Medical Treatments:
  1. There is no specific treatment for measles; it is managed symptomatically.
  2. Prescribe the following drugs based on symptoms:
    • Antibiotics to treat underlying infections (e.g., Cephalexin or Amoxyl syrup).
    • Intravenous Ceftriaxone for severe cases.
    • Analgesics to reduce pain and fever (e.g., Syrup Cetamol).
    • Antihistamines to reduce itching (e.g., Calamine lotion).
    • Vitamins A capsules for children below 1 year to prevent eye complications.
    • Grovit drops or syrup multivitamin to improve appetite.

Fluids and Diet:

  1. Provide plenty of oral fluids to replace lost fluids due to vomiting and diarrhea.
  2. Offer easily digestible foods rich in vitamins and proteins for quick recovery.
  3. Encourage the child to take frequent small meals.
  4. Use a nasogastric tube for feeding if the child cannot eat or drink.
  5. Administer intravenous fluids in cases of severe dehydration.

Skin Care:

  1. Pad the fingers to prevent excessive scratching of the skin.
  2. Apply prescribed calamine lotion to relieve itching.

Mouth and Eye Care:

  1. Emphasize oral hygiene with frequent mouth care using warm saline.
  2. Keep the nostrils clean and maintain cleanliness around the nasogastric tube.
  3. Apply gentian violet 1% for mouth ulcers.
  4. Use glycerin borax to lubricate the lips and prevent cracking.
  5. Clean the eyes with warm saline and avoid rubbing them.
  6. Apply TEO ointment if necessary.
  7. If one eye is affected, encourage the child to lie on the affected side to prevent infecting the other eye.
  8. Avoid direct sunlight on the eyes.

Hygiene and Bed Rest:

  1. Give the patient a daily bath and change bedding frequently.
  2. Use appropriate precautions for discharging ears and administer antibiotics as needed.
  3. Disinfect used soiled linen and utensils.
  4. Properly dispose of used swabs, discharges, or secretions.

Visitor and Ward Management:

  1. Restrict visitors and maintain visiting hours.
  2. Keep radio and TV volumes low to allow for patient rest.
  3. Encourage dim lighting due to photophobia.
  4. Encourage adequate sleep by switching off lights and minimizing noise.


  1. Continue monitoring the patient’s general condition and vital signs regularly.
  2. Take note of any deviations from the normal and act accordingly.
  3. Perform tepid sponging, give cold drinks, and apply cold compress on the forehead if the temperature is very high.

Bowel and Bladder Care:

  1. Observe and treat diarrhea or constipation as needed.
  2. Monitor and address any issues with the child’s urine output.

Exercises and Health Education:

  1. Encourage the patient to do active and passive exercises, including deep breathing exercises.
  2. Stimulate the child’s mind with play objects like toys.
  3. Educate the mother/caregiver about the mode of spread, signs, symptoms, and prevention of measles.

Complications of Measles:

  • Pneumonia
  • Acute Laryngo-Tracheo-Bronchitis (LTB)
  • Otitis media leading to deafness
  • Conjunctivitis
  • Encephalitis
  • Acute gastroenteritis
  • Malnutrition (PEM) – Kwashiorkor and marasmus
  • Subacute sclerosing panencephalitis.

Test Questions

MCQ: Which virus causes measles?
a) Influenza virus
b) Morbillivirus
c) Respiratory syncytial virus
d) Rotavirus
Answer: b) Morbillivirus
Explanation: Measles is caused by the morbillivirus, a member of the Paramyxoviridae family.

MCQ: During which stage of measles does the characteristic red maculo-papular rash appear?
a) Incubation stage
b) Prodromal stage
c) Catarrhal stage
d) Convalescence stage
Answer: c) Catarrhal stage
Explanation: The characteristic red maculo-papular rash appears during the catarrhal or eruptive stage of measles.

MCQ: What is the primary aim of nursing care in managing measles?
a) To reduce the risk of bacterial infection
b) To relieve itching and rash discomfort
c) To prevent complications and dehydration
d) To administer specific antiviral medication
Answer: c) To prevent complications and dehydration
Explanation: The primary aim of nursing care in managing measles is to prevent complications and dehydration, as there is no specific antiviral medication for measles.

MCQ: Which symptom is part of the classic triad used for suspecting measles?
a) Fever
b) Cough
c) Diarrhea
d) Jaundice
Answer: b) Cough
Explanation: The classic triad for suspecting measles includes cough, conjunctivitis, and coryza (common cold).

MCQ: What is the incubation period for measles?
a) 2-5 days
b) 7-10 days
c) 10-14 days
d) 21-28 days
Answer: c) 10-14 days
Explanation: The incubation period for measles typically lasts from 10 to 14 days.

MCQ: Which vitamin is administered to prevent eye complications related to measles in children below one year?
a) Vitamin B
b) Vitamin C
c) Vitamin D
d) Vitamin A
Answer: d) Vitamin A
Explanation: Vitamin A capsules are administered to children below one year to prevent eye complications associated with measles.

MCQ: Which stage of measles is characterized by an abrupt onset of severe symptoms, including very high fever and photophobia?
a) Incubation stage
b) Prodromal stage
c) Catarrhal stage
d) Convalescence stage
Answer: c) Catarrhal stage
Explanation: The catarrhal or eruptive stage of measles is characterized by an abrupt onset of severe symptoms, including very high fever and photophobia.

MCQ: What is the primary mode of measles transmission?
a) Contact with contaminated food
b) Direct skin-to-skin contact with an infected person
c) Airborne droplets from an infected person’s respiratory secretions
d) Ingestion of contaminated water
Answer: c) Airborne droplets from an infected person’s respiratory secretions
Explanation: Measles is primarily transmitted through airborne droplets when an infected person coughs or sneezes.

MCQ: Which of the following is NOT a risk factor for measles?
a) Immunodeficiency in children
b) Travel to areas where measles is endemic
c) Malnutrition
d) Taking vitamin supplements
Answer: d) Taking vitamin supplements
Explanation: Immunodeficiency, travel to endemic areas, and malnutrition are risk factors for measles, but taking vitamin supplements is not directly associated with measles risk.

MCQ: Which stage of measles marks the beginning of improvement, characterized by skin desquamation and a decline in body temperature?
a) Incubation stage
b) Prodromal stage
c) Catarrhal stage
d) Convalescence stage
Answer: d) Convalescence stage
Explanation: The convalescence or recovery stage of measles marks the beginning of improvement, characterized by skin desquamation, a decline in body temperature, and the resolution of symptoms.

Measles Read More »



Malaria is an infectious disease caused by a parasite belonging to the Plasmodium genus. It is primarily transmitted from one person to another through female mosquitoes of the Anopheles genus. The illness presents with acute febrile symptoms, including cycles of chills, fever, pain, and sweating.

Historical records indicate that malaria has been afflicting humans since ancient times. There are four main species of malaria parasites that affect humans, namely:

  1. Plasmodium falciparum
  2. Plasmodium vivax
  3. Plasmodium malariae
  4. Plasmodium ovale
  5. Plasmodium knowlesi

Among these, Plasmodium falciparum stands out as the most virulent malaria parasite worldwide and also happens to be the most prevalent one in Uganda.

Signs and Symptoms of Malaria

Malaria manifests through a variety of signs and symptoms, with fever being the most prominent and characteristic feature. The fever in malaria follows an intermittent pattern, coming and going repeatedly. A typical malaria attack can be categorized into three phases:

  1. The Cold Stage: During this stage, the patient experiences a sensation of coldness and shivers.

  2. The Hot Stage: In this stage, the patient feels intense heat and feverish.

  3. The Sweating Stage: This stage is accompanied by profuse sweating and a sense of relief from symptoms.

Apart from fever, other common symptoms of malaria include:

  • Loss of appetite
  • Weakness and lethargy
  • Nausea and vomiting
  • Headache
  • Joint and muscle pains
  • Diarrhea
  • Dehydration
  • Enlarged spleen (spleenomegaly)

In severe and complicated cases of malaria, the following symptoms may arise:

  • Changes in behavior, confusion, or drowsiness
  • Altered level of consciousness or coma
  • Convulsions
  • Hypoglycemia (low blood sugar levels)
  • Acidosis (excess acid in the body)
  • Difficulty in breathing, often due to pulmonary edema or respiratory distress syndrome
  • Acute renal failure
  • Severe anemia
  • Shock
  • Presence of hemoglobin in urine (haemoglobinuria)
  • Oliguria with very dark urine (similar to the color of coca-cola or coffee)
  • Jaundice (yellowing of the skin and eyes)
  • Bleeding tendency
  • Prostration (extreme weakness)
  • High levels of malaria parasites in the blood (hyperparasitaemia)
  • Extremely high body temperature (hyperpyrexia)
  • Severe vomiting

Transmission of Malaria

Malaria is transmitted to humans through the bite of an infected female Anopheles mosquito, which injects malaria parasites (sporozoites) into the bloodstream. The life cycle of the malaria parasite (Plasmodium) is complex and involves two hosts: humans and Anopheles mosquitoes.

Illustration of the Malaria Parasite Life Cycle:

Illustration of the Malaria Parasite Life Cycle:

  1. Infection begins when an infected female Anopheles mosquito bites a person, introducing Plasmodium sporozoites into the bloodstream.
  2. The sporozoites swiftly move into the human liver.
  3. Over the next 7 to 10 days, the sporozoites multiply asexually in liver cells, causing no noticeable symptoms.
  4. The parasites, now in the form of merozoites, are released from liver cells and travel through the heart to the lungs, where they settle within lung capillaries. The vesicles eventually disintegrate, releasing merozoites into the blood phase of their development.
  5. In the bloodstream, the merozoites invade red blood cells (erythrocytes) and undergo further multiplication until the cells burst. They then invade more erythrocytes, repeating this cycle and causing fever each time they break free and infect new blood cells.
  6. Some of the infected blood cells deviate from the asexual multiplication cycle and instead develop into sexual forms of the parasite known as gametocytes, which circulate in the bloodstream.
  7. When an infected mosquito bites a human, it ingests these gametocytes, which further mature into sexually active gametes within the mosquito.
  8. The fertilized female gametes transform into mobile ookinetes that penetrate the mosquito’s midgut wall, forming oocysts on its exterior surface.
  9. Inside the oocyst, numerous active sporozoites develop. Eventually, the oocyst bursts, releasing sporozoites into the mosquito’s body cavity, which then migrate to its salivary glands.
  10. The cycle of human infection begins anew when the mosquito bites another person.
Incubation Period:

The period between the mosquito bite and the onset of malarial illness typically ranges from one to three weeks (7 to 21 days). 

However, certain types of malaria, such as P. vivax and P. ovale, may take much longer, up to eight to 10 months, to cause symptoms. These parasites remain dormant (inactive or hibernating) in the liver cells during this extended period. 

Unfortunately, some dormant parasites may persist even after a patient recovers from malaria, leading to the possibility of relapsing malaria, wherein the patient may fall ill again.

Diagnosis of Malaria

Diagnosing malaria involves considering the patient’s clinical signs and symptoms, which can be challenging due to the similarity of malaria symptoms with other diseases, including yellow fever, typhoid fever, respiratory tract infections, meningitis, otitis media, tonsillitis, skin sepsis, and measles.

The following investigations are crucial in accurately confirming a malaria diagnosis:

  1. Blood Smear Examination (Malaria Parasite Smear – MPS): The classic and widely used diagnostic test for malaria involves examining a blood smear under a microscope. A small amount of the patient’s blood is placed on a microscope slide, stained, and then observed for the presence of malaria parasites inside red blood cells. This test helps identify the Plasmodium species.

  2. Rapid Diagnostic Tests (RDTs): Rapid diagnostic tests detect specific malaria antigens or proteins in the patient’s blood. RDTs are especially useful in areas with limited access to microscopy facilities and can provide rapid results for immediate management.

  3. Complete Blood Count (CBC): A CBC is essential for evaluating the overall health of the patient and can reveal valuable information about the levels of different blood components, including red blood cells and white blood cells. In malaria, a decrease in red blood cells (anemia) is often observed.

  4. Hemoglobin Estimation: Hemoglobin estimation provides information about the patient’s hemoglobin levels, which can be significantly affected in malaria due to the destruction of red blood cells.

  5. Liver Function Tests (LFTs): In certain cases, liver function tests may be conducted to assess liver health, as the malaria parasites initially multiply in the liver.

  6. Blood Chemistry Panel: A blood chemistry panel may be performed to evaluate various parameters, including electrolyte levels, kidney function, and liver enzymes, providing a comprehensive picture of the patient’s overall health status.

  7. Polymerase Chain Reaction (PCR): PCR is a highly sensitive molecular technique that can detect the genetic material of malaria parasites in the blood. It is particularly useful for detecting low levels of parasites and differentiating between various Plasmodium species.

  8. Serological Tests: Serological tests detect specific antibodies produced by the body in response to malaria infection. These tests may not be suitable for early diagnosis but can be valuable for determining past exposure to malaria.

Treatment of Malaria

  1. Treatment of Uncomplicated Malaria:
  • The recommended first-line medication for uncomplicated malaria is Artemether/Lumefantrine (Coartem).
  • In case Artemether/Lumefantrine is unavailable, the first-line alternative treatment is Atesunate + Amodiaquine.
  • The recommended second-line medication is Dihydroartemisinin + Piperaquine (Duocotecxin).
  1. Treatment of Severe and Complicated Malaria:
  • Parenteral Artesunate is the recommended treatment for managing severe malaria in all patients.
  • In the absence of Artesunate, Parenteral Quinine or Artemether can be used as alternatives.
  1. Treatment of Malaria in Pregnancy:
  • Uncomplicated malaria:
    • First trimester: Quinine tablets.
    • Second and third trimesters: Artemether/Lumefantrine or Quinine tablets.
  • Severe malaria in pregnancy should be treated with intravenous Artesunate.
Additional Treatment Measures:
  1. Antipyretic to Reduce Body Temperature:
  • Paracetamol: 10mg/kg body weight every six hours in children, 1g 6-8 hourly in adults.
  • Tepid sponging or fanning can also be used to reduce fever.
  1. Anticonvulsants:
  • Diazepam: 0.2mg/kg body weight intravenously or intramuscularly in adults.
  1. Treat Detectable Causes of Convulsions:
  • For example, hypoglycemia can be managed with Dextrose administration.
  1. Nursing Care:
  • Provide supportive care and symptomatic treatment, such as tepid sponging for fever.
  • Regularly observe temperature, pulse, respiration rate, and blood pressure. Record all observations.
  • Educate patients on personal protection, malaria prevention, and the importance of adhering to treatment.
  • Administer antiemetic medicine 30 minutes to 1 hour before antimalarial drugs if vomiting occurs.
  • Advise patients to rest for 1-2 hours after taking the medicine to avoid dizziness, vomiting, and hypotension.
  • Offer psychological support and comfort to patients.
  • Encourage a nourishing diet with plenty of oral fluids. In cases of difficulty in eating or drinking, consider passing a naso-gastric tube.
  • Monitor fluid intake and output and maintain a fluid balance chart.
  • Ensure proper patient and environmental hygiene.

Complications of Malaria:

  • Impaired consciousness/coma
  • Severe anemia
  • Renal failure
  • Pulmonary edema
  • Acute respiratory distress syndrome
  • Shock
  • Spontaneous bleeding
  • Acidosis
  • Hemoglobinuria (hemoglobin in urine)
  • Jaundice
  • Repeated generalized convulsions.
Prevention and Control of Malaria

Prevention and Control of Malaria

  1. Implement Effective Treatment and Prophylaxis:
  • Early diagnosis and prompt treatment are essential to eliminate parasites from the human population. Timely treatment helps prevent the spread of malaria.
  • Vulnerable groups, such as pregnant women, should receive chemoprophylaxis (preventive medication). The following drugs are used for this purpose: Chloroquine, Doxycycline, Mefloquine, and Primaquine.
  • All pregnant women should be provided with Intermittent Preventive Treatment (IPT) to protect both the mother and the unborn child from malaria.
  1. Reduce Human-Mosquito Contact:
  • Encourage the use of insecticide-treated nets (ITNs) while sleeping to create a physical barrier between individuals and malaria-carrying mosquitoes.
  • Implement indoor residual spraying of dwellings with insecticides or use knockdown sprays to control adult mosquitoes within households.
  • Advise individuals to wear clothing that covers the arms and legs, and to use mosquito repellent coils and creams when sitting outdoors at night to prevent mosquito bites.
  1. Control Breeding Sites:
  • Eliminate stagnant water collection sites where mosquitoes breed, such as empty cans/containers, potholes, old car tires, and plastic bags. This can be achieved through proper disposal, draining, or covering with soil.
  • Use insecticides to treat stagnant water bodies to destroy mosquito larvae, or employ biological methods such as introducing larvae-eating fish to these water sources.
  1. Provide Public Health Education:
  • Conduct public health education campaigns to raise awareness about malaria prevention measures, including the use of mosquito nets, personal protection measures, and the importance of seeking early diagnosis and treatment.
  • Educate communities about the significance of eliminating breeding sites and promoting good environmental hygiene to reduce mosquito populations.

Test Questions.

What is the primary mode of transmission of malaria to humans?
a) Contaminated food and water
b) Contact with infected animals
c) Bites from female Anopheles mosquitoes
d) Airborne droplets from infected individuals
Answer: c) Bites from female Anopheles mosquitoes
Explanation: Female Anopheles mosquitoes transmit malaria by injecting malaria parasites (sporozoites) into the bloodstream during their bite.
Which diagnostic test is considered the gold standard for confirming malaria infection?

a) Rapid Diagnostic Test (RDT)
b) Polymerase Chain Reaction (PCR)
c) Complete Blood Count (CBC)
d) Blood smear examination
Answer: d) Blood smear examination

Explanation: The blood smear examination under a microscope is the classic and most widely used diagnostic test for malaria. It allows visualization of malaria parasites inside red blood cells, helping to identify the Plasmodium species and guide appropriate treatment.

What is the recommended first-line treatment for uncomplicated malaria?
a) Artemether/Lumefantrine (Coartem)
b) Dihydroartemisinin + Piperaquine (Duocotecxin)
c) Quinine tablets
d) Doxycycline
Answer: a) Artemether/Lumefantrine (Coartem)

Explanation: Artemether/Lumefantrine is the recommended first-line medicine for treating uncomplicated malaria cases.

Which antimalarial drug is used as chemoprophylaxis to protect vulnerable groups from malaria?
a) Paracetamol
b) Chloroquine
c) Artemether
d) Diazepam
Answer: b) Chloroquine

Explanation: Chloroquine is one of the drugs used for chemoprophylaxis to protect vulnerable groups, such as pregnant women, from contracting malaria.

What intervention can help reduce human-mosquito contact and prevent malaria transmission?
a) Wearing clothes that cover the arms and legs
b) Spraying dwellings with insecticides
c) Drinking boiled water
d) Applying sunscreen
Answer: a) Wearing clothes that cover the arms and legs

Explanation: Wearing clothes that cover the arms and legs can help reduce mosquito bites and lower the risk of malaria transmission.

In severe malaria cases, what is the recommended first-line treatment for all patients?
a) Parenteral Quinine
b) Parenteral Artesunate
c) Intramuscular Artemether
d) Parenteral Mefloquine
Answer: b) Parenteral Artesunate

Explanation: Parenteral Artesunate is the recommended first-line treatment for severe malaria in all patients.

How long is the incubation period for malaria?
a) 1-3 days
b) 1-3 weeks
c) 1-3 months
d) 1-3 years
Answer: b) 1-3 weeks

Explanation: The incubation period for malaria is usually 1-3 weeks (7 to 21 days) after the mosquito bite.

Which complication of malaria is characterized by the presence of hemoglobin in urine?
a) Severe anemia
b) Jaundice
c) Acidosis
d) Hemoglobinuria
Answer: d) Hemoglobinuria

Explanation: Hemoglobinuria is the presence of hemoglobin in urine, which can occur as a complication of malaria.

What method is used to control mosquito breeding sites and prevent malaria transmission?
a) Introducing larvae-eating fish
b) Using insect repellent coils
c) Administering antimalarial drugs
d) Fumigating dwellings with pesticides
Answer: a) Introducing larvae-eating fish

Explanation: Introducing larvae-eating fish to stagnant water bodies is a biological method used to control mosquito larvae and prevent malaria transmission.

How can midwifery students contribute to malaria prevention in pregnant women?
a) Administering chemoprophylaxis during pregnancy
b) Providing insecticide-treated nets to pregnant women
c) Educating pregnant women about personal protection measures
d) All of the above
Answer: d) All of the above

Explanation: Midwifery students can play a vital role in malaria prevention for pregnant women by administering chemoprophylaxis, distributing insecticide-treated nets, and educating them about personal protection measures against malaria.

Malaria Read More »

Typhoid Fever (Enteric Fever)

Typhoid Fever (Enteric Fever)

Typhoid fever is an acute bacterial infection characterized by fever and is primarily spread through contaminated food and water.


Typhoid fever is caused by Salmonella typhi and Salmonella paratyphi A and B.


  • Typhoid fever is contracted by the ingestion of the bacteria in contaminated food or water.
  • Patients with acute illness can contaminate the surrounding water supply through stool, which contains a high concentration of the bacteria.
  • About 3-5% of patients become carriers of the bacteria after the acute illness. Some patients suffer a very mild illness that goes unrecognized, and these patients can become long-term carriers of the bacteria.
  • The bacteria multiply in the gallbladder, bile ducts, or liver and pass into the bowel.
  • The bacteria can survive for weeks in water or dried sewage.
  • The chronic carriers may have no symptoms and can be the source of new outbreaks of typhoid fever for many years.
Signs and Symptoms of Typhoid Fever

Signs and Symptoms of Typhoid Fever

Classically, the course of untreated typhoid fever is divided into four stages, each lasting approximately one week.

First week:

  • In the first week, there is a gradual rise in temperature (step-ladder fashion) accompanied by bradycardia, malaise, headache, generalized body aching, restlessness, and cough.
  • Epistaxis (nosebleeds) is observed in about a quarter of cases.
  • Abdominal pain may also be present.
  • Leukopenia, eosinopenia, and relative lymphocytosis are evident in blood tests.
  • The classic Widal test, used to detect antibodies against Salmonella, is negative in the first week, but blood culture reveals the presence of Salmonella typhi.
  • The payer patches of the distal end of the ileum are invaded by the bacillus and become inflamed, resulting in various manifestations such as slow pulse rate, severe persistent frontal headache, general malaise, anorexia, nausea, vomiting, intestinal upset (diarrhea and constipation), and depression of bone marrow.

Second week:

  • The payer patches form a slough (a layer of dead skin).
  • In the second week of the infection, the patient becomes severely ill with high fever, often reaching around 40°C (104°F), and bradycardia.
  • Delirium is common, characterized by a state of calmness or, at times, agitation.
Rose spots
Rose spots
  • Rose spots, which are pink spots, appear on the lower chest and abdomen in about one-third of patients.
  • The abdomen becomes distended and painful, especially in the right lower quadrant.
  • Diarrhea may occur, with stool appearing green and having a characteristic smell resembling pea soup. However, constipation can also be frequent.
  • The spleen and liver enlarge (hepatosplenomegaly) and become tender.
  • The Widal reaction shows strong positivity with anti-O and anti-H antibodies, while blood cultures may still be positive at this stage.
  • The tongue is coated with a brownish fur, and sordes indicate severe toxemia.
  • Dehydration becomes evident.

Third week:

  • In the third week of typhoid fever, several complications may arise:
    • The slough separates, leaving deep ulcers in the intestines.
    • Ulcers may erode blood vessels, leading to hemorrhage, or perforate the ileum, causing leakage of intestinal contents into the peritoneal cavity.
    • The patient becomes extremely ill and toxic.
    • Temperature remains very high and intermittent.
    • Pulse becomes feeble.
    • The patient lapses into a typhoid state, experiencing delirium and confusion.
    • Twitching of limbs may occur due to loss of calcium in the diarrhea state.
    • Carforragic picking may lead to clotting issues and blood-stained clothes.
    • Tough dries and flurried lips are observed due to severe dehydration from profuse diarrhea.
    • Signs of congestive cardiac failure (CCF) due to weakened myocardium may be present.
    • The patient may experience coma every eight hours.
    • Peritonitis, inflammation of the peritoneum, may occur.
  • By the end of the third week, the patient becomes emaciated, fever starts to subside, abdominal symptoms become more pronounced, and mental disturbances become prominent.

Fourth week:

  • The ulcers begin to heal through granulation.
  • At the beginning of the fourth week, the fever begins to decline, and the other symptoms gradually reduce as the patient’s temperature returns to normal.
  • Recovery is slow during this stage, and relapses are common.
  • If left untreated, typhoid fever can prove fatal in up to 25% of all cases.

Investigations for Typhoid Fever:

  1. Stool Culture: Stool culture involves collecting a sample of the patient’s stool and incubating it under specific conditions to identify and isolate the causative bacteria, usually Salmonella typhi or Salmonella paratyphi. The presence of these bacteria in the stool confirms the diagnosis of typhoid fever. 

  2. Blood Culture:  Blood sample is collected and cultured in a suitable medium to identify and isolate the bacteria causing typhoid fever. A blood culture is an effective method to confirm the diagnosis, especially in the early stages of the disease when stool cultures might be negative.

  3. Widal Test: The Widal test is a serological test used to detect antibodies produced by the body in response to the infection by Salmonella typhi. The test measures the presence of specific antibodies, including anti-O and anti-H antibodies, in the patient’s blood. A positive Widal test suggests a recent or past infection with typhoid fever. However, it is important to note that the Widal test results should be interpreted cautiously, as false-positive results can occur due to cross-reactivity with other infections or previous vaccinations.

Additional Investigations (optional):

  1. Polymerase Chain Reaction (PCR) Test: PCR is a molecular diagnostic test that can detect the genetic material (DNA or RNA) of the Salmonella bacteria directly from clinical samples, such as blood or stool. PCR is a highly sensitive and specific method, and it can provide rapid results, aiding in early detection and timely treatment of typhoid fever.

  2. Typhoid Serology: Typhoid serology involves analyzing the patient’s blood for specific antibodies against Salmonella typhi. This test, similar to the Widal test, helps in confirming a recent or past infection, but it may have limitations in terms of sensitivity and specificity.

  3. Complete Blood Count (CBC): A CBC is a routine blood test that provides information about the number and types of blood cells. In typhoid fever, the CBC may show leucopenia (low white blood cell count), eosinopenia (low eosinophil count), and relative lymphocytosis (increased lymphocyte percentage). These abnormalities can help in supporting the diagnosis of typhoid fever.

  4. Liver Function Tests (LFTs): Liver function tests assess the health of the liver and its ability to function properly. In typhoid fever, liver involvement is common, and LFTs can reveal elevated liver enzymes and other liver-related abnormalities.

  5. Urinalysis: Urinalysis may be performed to check for the presence of white blood cells or other indicators of kidney involvement, which can occur in severe cases of typhoid fever.

Complications of Typhoid Fever:

I. Gastrointestinal Complications:
A. Perforation: The ulcerated areas in the intestines can lead to perforation, causing leakage of intestinal contents into the abdominal cavity. This can result in severe abdominal pain and peritonitis.
B. Hemorrhage: The erosion of blood vessels by ulcers can cause gastrointestinal bleeding, leading to blood loss and anemia.
C. Peritonitis: Perforation of the intestine can lead to peritonitis, an inflammation of the peritoneum (the lining of the abdominal cavity), causing severe abdominal pain and tenderness.

II. Gallbladder Complications:
A. Cholecystitis: The infection can spread to the gallbladder, causing inflammation known as cholecystitis, which leads to abdominal pain, fever, and tenderness in the right upper abdomen.

III. Respiratory Complications:
A. Pneumonia: In severe cases, typhoid fever can lead to pneumonia, a lung infection characterized by fever, cough, and difficulty breathing.

IV. Cardiovascular Complications:
A. Heart Failure: Severe and untreated typhoid fever can put a strain on the heart, leading to congestive heart failure, a condition where the heart fails to pump blood effectively, resulting in fluid accumulation in the body.

V. Musculoskeletal Complications:
A. Osteomyelitis: In rare cases, typhoid fever bacteria can spread to the bones, causing osteomyelitis, which is an infection of the bone and bone marrow.

VI. Neurological Complications:
A. Encephalitis: Typhoid fever can lead to encephalitis, which is inflammation of the brain. This can cause symptoms such as headache, confusion, and altered mental state.

B. Meningitis: In some instances, the infection may also spread to the meninges, the protective membranes covering the brain and spinal cord, leading to meningitis. 

C. Mental Confusion: During the advanced stages of the disease, mental confusion and delirium may occur due to the systemic effects of the infection on the central nervous system.

Management of Typhoid Fever

  1. Hospital Admission:
  • In severe cases of typhoid fever, hospital admission is necessary to provide close monitoring and appropriate medical care.
  1. Isolation or Barrier Nursing:
  • Patients with typhoid fever should be isolated or barrier nursed to prevent the spread of the infection to others.
  1. Investigations:
  • Blood for Culture and Sensitivity (C/S) should be performed during the first week to identify the causative bacteria and determine its sensitivity to antibiotics.
  • Full Blood Sample (FBS) analysis will reveal low Hemoglobin (Hb) levels, low White Blood Cell (WBC) count, and an increased Erythrocyte Sedimentation Rate (ESR).
  • The Widal test can be done around 10/7 days after the onset of symptoms to detect antibodies against typhoid bacilli.
  • Blood Smear (B/S) examination should be conducted to rule out malaria.
  • Stool analysis and urinalysis are important to assess gastrointestinal and urinary involvement in typhoid fever.
  1. Drug Therapy:
  • Antibiotic therapy is a cornerstone of typhoid fever management:
    • Ciprofloxacin at a dose of 500-750 mg twice daily for 10/7 (10 days).
    • Azithromycin at a dose of 10 mg/kg daily.
    • Cotrimoxazole at a dose of 960 mg twice daily for 3/7 (3 days) or as per a weight-based calculation for 10/7 (10 days).
  1. Long-Term Carriers:
  • After signs have passed, stool tests should be conducted to check if Salmonella typhi bacilli are still present. Patients may become potential long-term carriers of the bacteria, requiring a 28-day course of antibiotics to eliminate the bacteria until they are free from it.
  1. Fluid and Electrolyte Management:
  • Monitor intravenous (IV) fluid administration for rehydration.
  • Correct fluid and electrolyte imbalances with Normal Saline (N/S), Dextrose 5% (D5%) solutions, and oral fluids.
  1. Nutrition:
  • Ensure adequate nutrition and provide a soft, easily digestible diet, unless the patient has abdominal complications or ileus.
  1. Antipyretics:
  • Administer antipyretics like Paracetamol (PCM) to manage fever.
  1. Hygiene and Infection Control:
  • Pay close attention to handwashing and limit close contact with individuals during the acute phase of the infection to prevent its spread.
  • Encourage proper waste disposal, covering of food, and proper food preparation to reduce contamination risks.
  • Encourage early screening and management to prevent the worsening of the disease.
  1. Proper Water Treatment and Storage:
  • Educate patients on the proper treatment and storage of water to avoid waterborne transmission of the bacteria.
  1. Regular Follow-Up and Monitoring:
  • Ensure regular follow-up and monitor for complications and clinical relapses.
  1. Management of Delirium:
  • Encourage the use of Phenobarbital at a dose of 30-60 mg in case of delirium.


  • Maintain cleanliness in the premises and ensure proper disposal of rubbish.
  • Keep hands clean and maintain trimmed fingernails.
  • Wash hands thoroughly with soap and water before eating or handling food and after using the toilet or changing diapers.
  • Drinking water should be free from microorganisms; it is preferable to boil water before consumption.
  • Avoid high-risk foods, such as raw or semi-cooked food.
  • During food preparation, wear clean, washable aprons, and caps.
  • Clean and wash food thoroughly, including scrubbing and rinsing fruits in clean water.
  • Store perishable food in the refrigerator, covering it properly.
  • Cook food thoroughly before consumption.
  • Consume food as soon as it is prepared.
  • If necessary, refrigerate cooked leftover food and consume it promptly. Reheat it thoroughly before consumption.
  • Exclude infected individuals and asymptomatic carriers from handling food and providing care to children.
  • Consider immunization, especially for those traveling to high-risk areas, where vaccines are available in oral and injectable forms.

Test MCQ Questions

Question 1:
What is the primary mode of transmission for typhoid fever?
A) Mosquito bites
B) Contaminated food and water
C) Airborne droplets
D) Direct physical contact

Question 2:
Which bacterium is responsible for causing typhoid fever?
A) Escherichia coli
B) Salmonella typhi
C) Streptococcus pneumoniae
D) Staphylococcus aureus

Question 3:
Which of the following complications can occur in severe cases of typhoid fever?
A) Fractures
B) Renal failure
C) Dental caries
D) Cholecystitis

Question 4:
Which diagnostic test is used to identify the presence of Salmonella typhi in the blood?
A) Blood smear examination
B) Stool culture
C) Urinalysis
D) Blood culture

Question 5:
What is the recommended antibiotic therapy for treating typhoid fever?
A) Penicillin
B) Amoxicillin
C) Ciprofloxacin
D) Erythromycin

Question 6:
Why is hospital admission often recommended in severe cases of typhoid fever?
A) To provide psychological support to the patient
B) To administer vaccines for long-term immunity
C) To ensure isolation and prevent disease transmission
D) To allow close monitoring and provide appropriate medical care

Question 7:
What is the primary preventive measure to avoid typhoid fever transmission in the community?
A) Proper handwashing with soap and water
B) Mosquito net usage
C) Wearing masks in public places
D) Vaccination against other bacterial infections

Question 8:
Which gastrointestinal complication can occur due to typhoid fever?
A) Pneumonia
B) Peritonitis
C) Otitis media
D) Conjunctivitis

Question 9:
Which of the following is NOT a recommended step to prevent typhoid fever?
A) Drinking untreated water from natural sources
B) Cooking food thoroughly
C) Washing hands properly before eating
D) Proper waste disposal

Question 10:
Who should be excluded from handling food and providing care to children during a typhoid fever outbreak?
A) Asymptomatic carriers and infected individuals
B) Healthcare professionals only
C) Pregnant women
D) Children under 5 years of age


  1. B – Contaminated food and water
  2. B – Salmonella typhi
  3. D – Cholecystitis
  4. D – Blood culture
  5. C – Ciprofloxacin
  6. D – To allow close monitoring and provide appropriate medical care
  7. A – Proper handwashing with soap and water
  8. B – Peritonitis
  9. A – Drinking untreated water from natural sources
  10. A – Asymptomatic carriers and infected individuals


  1. Typhoid fever is primarily spread through contaminated food and water, making option B the correct answer.
  2. Salmonella typhi is the bacterium responsible for causing typhoid fever, making option B the correct answer.
  3. Cholecystitis is one of the gastrointestinal complications associated with typhoid fever, making option D the correct answer.
  4. Blood culture is used to identify the presence of Salmonella typhi in the blood, making option D the correct answer.
  5. Ciprofloxacin is one of the recommended antibiotics for treating typhoid fever, making option C the correct answer.
  6. Hospital admission is recommended in severe cases of typhoid fever for close monitoring and appropriate medical care, making option D the correct answer.
  7. Proper handwashing with soap and water is the primary preventive measure to avoid typhoid fever transmission, making option A the correct answer.
  8. Peritonitis is a gastrointestinal complication that can occur due to typhoid fever, making option B the correct answer.
  9. Drinking untreated water from natural sources is NOT a recommended step to prevent typhoid fever, making option A the correct answer.
  10. Asymptomatic carriers and infected individuals should be excluded from handling food and providing care to children during a typhoid fever outbreak, making option A the correct answer.

Typhoid Fever (Enteric Fever) Read More »


Bacillary Dysentery (Shigellosis):

Bacillary dysentery is an acute bacterial disease that primarily affects the large and small intestine, leading to symptoms such as bloody mucoid diarrhea.

 It is important not to confuse bacillary dysentery with diarrhea caused by other bacterial infections, as one of the distinguishing characteristics of bacillary dysentery is the presence of blood in the stool, resulting from the invasion of the pathogen into the mucosa.


    • Bacillary dysentery is caused by different types of Shigella bacteria, including Shigella sonnei, Shigella flexneri, and Shigella dysenteriae.

Mode of Transmission:

    • Bacillary dysentery can be transmitted directly through fecal material of a patient or carrier.
    • It can also be transmitted indirectly through contaminated food and water.
    • Infection can occur even after consuming a small number of bacteria, making household spread and transmission in institutions highly likely.
    • Young children are particularly susceptible to this infection.

Clinical Features:

    • Incubation period: 1-3 days (can extend up to 7 days).
    • Common symptoms include:
      • Sudden onset of mucoid bloody diarrhea.
      • Fever.
      • Nausea and vomiting.
      • Abdominal cramps.
      • Tenesmus (sensation of desire to defecate without producing significant amounts of feces).
      • Flatulence.
      • Headache and fatigue.
      • Dehydration.


    • Fresh stool samples are collected for culture and sensitivity testing, as well as microscopy to identify the causative bacteria.


    • Admission to a medical ward in isolation.
    • Strict personal hygiene (barrier nursing) to prevent infecting others.
    • Disinfection of the patient’s bed and other items used.
    • Proper disposal of fecal matter and vomit into a pit latrine.
    • Regular monitoring of temperature, pulse, respiration, blood pressure, hydration levels, and level of consciousness.
    • Providing reassurance and support to the patient and relatives.
    • Fluid intake maintenance using Oral Rehydration Solution (ORS) or intravenous fluids in severe cases.
    • Antibiotic treatment with drugs like nalidixic acid or ciprofloxacin.
    • Implementing a BRAT diet (bananas, rice, applesauce, toast) to aid in recovery.
    • Use of a nasogastric tube for feeding and medication administration if oral intake is not possible.
    • Medications for managing nausea and vomiting, such as metoclopramide (plasil).
    • Close monitoring of hydration levels and maintenance of a fluid balance chart.


    • Maintain cleanliness in premises and kitchen utensils.
    • Proper disposal of rubbish.
    • Practice proper hand hygiene before eating or handling food, and after using the toilet or changing diapers.
    • Boil or treat drinking water.
    • Avoid high-risk foods like shellfish, raw or semi-cooked food.
    • Use clean washable aprons and caps during food preparation.
    • Thoroughly clean and wash food items, including fruits, in clean water.
    • Store perishable food in a well-covered refrigerator.
    • Ensure thorough cooking of food before consumption.
    • Consume food promptly or refrigerate leftovers and reheat thoroughly before eating.
    • Exclude infected individuals and asymptomatic carriers from handling food or providing care to children.

Amoebic Dysentery (Amoebiasis)

Amoebic dysentery is a parasitic infection of the gastrointestinal system that is caused by the parasite Entamoeba histolytica

The infection is most commonly acquired through oral-fecal contamination, which can occur by consuming contaminated food or water, or by coming into contact with contaminated feces and not washing your hands properly.

Symptoms of amoebic dysentery 

  • Violent diarrhea, often with blood and/or mucus in the stools
  • Severe colitis
  • Frequent flatulence
  • Dehydration
  • Abdominal cramps and tenderness
  • Slight weight loss
  • Moderate anemia
  • Moderate fever
  • Mild fatigue
  • Unrelated symptoms such as liver abscess, lung involvement, amoeboma swelling, and anal ulceration


The diagnosis of amoebic dysentery is usually made by examining a stool sample under a microscope to look for cysts or motile organisms. Ultrasound scans may also be performed.


The treatment of amoebic dysentery involves several steps:

  1. Correcting any dehydration
  2. Initiating a 10-day course of the antimicrobial drug metronidazole (Flagyl) or tinidazole to eliminate the infection
  3. Administering amoebicidal (lumenal) drugs such as diloxanide furoate, paromomycin, or iodoquinol to eradicate any remaining parasites
  4. Isolating infected individuals to prevent further spread of the infection
  5. Emphasizing personal hygiene practices


To prevent the occurrence and transmission of amoebic dysentery, the following preventive measures should be followed:

  • Educate the public about proper handwashing before eating and appropriate fecal disposal practices.
  • Ensure the proper management of carriers of the infection.
  • Promote the use of clean drinking water and safe food handling practices.

Dysentery Read More »



Cholera is an infection of the small intestine caused by the bacterium Vibrio cholerae.

The infection is characterized by profuse watery stools, vomiting, dehydration, and collapse. 


  • Cholera is specifically caused by the bacterium Vibrio cholerae.

This bacterium is Gram stain negative and possesses a flagellum, a long projecting part that enables it to move, and pili, hair-like structures that it uses to attach to the intestinal tissue.


  • The primary mode of transmission for cholera is through the fecal contamination of food and water, often resulting from poor sanitation practices. When individuals infected with cholera have untreated diarrheal discharge, the bacteria can enter waterways or drinking water supplies, contaminating them.
  • Consuming food that has been washed in contaminated water can also lead to transmission. It is important to note that cholera is rarely spread directly from person to person.

Susceptibility: Several factors influence the susceptibility to cholera:

  1. Ingestion of bacteria: In a normal, healthy adult, approximately 100 million bacteria must typically be ingested to cause cholera. This highlights the importance of a significant bacterial load for infection to occur.

  2. Age: Children, particularly those between the ages of two and four, are more susceptible to cholera infection. This could be attributed to their underdeveloped immune systems and increased likelihood of exposure due to their behavior and hygiene practices.

  3. Lowered immunity: Individuals with weakened immune systems, such as those with AIDS or malnourished children, are at higher risk of experiencing severe cases if they become infected with cholera. Their compromised immune function makes it more difficult for their bodies to fight off the infection effectively.

Pathophysiology of Cholera

Cholera is a gastrointestinal illness caused by the bacterium Vibrio cholerae. The bacteria produce a toxin that causes the body to lose water and electrolytes, leading to severe diarrhea.

How the Bacteria Enter the Body

Most Vibrio cholerae bacteria are killed by the acidic environment of the stomach. However, a small number of bacteria can survive and travel to the small intestine. The bacteria attach to the intestinal wall and produce a toxin that causes the body to lose water and electrolytes.

The Toxin

The toxin produced by Vibrio cholerae is called cholera enterotoxin. The toxin binds to cells in the small intestine and activates an enzyme that causes the cells to pump water and electrolytes into the intestine. This results in the production of large amounts of watery diarrhea.

More Detailed Pathophysiology:
Upon consumption, most Vibrio cholerae bacteria do not survive the acidic conditions of the human stomach. However, a small number of bacteria manage to survive. As they exit the stomach and reach the small intestine, they need to navigate through the thick mucus lining in order to reach the intestinal walls, where they can establish themselves and multiply. Vibrio cholerae bacteria possess flagella for mobility and pili to attach to the intestinal tissue.

Vibrio cholerae bacteria produce a toxin that is responsible for causing the most severe symptoms of cholera. This toxin, known as an enterotoxin, acts on human cells, prompting them to extract water and electrolytes from the body, primarily from the upper gastrointestinal tract. The extracted fluid and electrolytes are then pumped into the intestinal lumen, resulting in the excretion of diarrheal fluid.

Signs and Symptoms

The incubation period for cholera is typically 2-3 days. The first signs and symptoms of cholera are watery diarrhea and vomiting. The diarrhea can be so profuse that it can lead to dehydration and shock.

In a typical case of severe cholera, the disease progresses through three stages:

Stage I:

  • Profuse watery stools are expelled by the patient. Over time, fecal matter becomes nearly clear fluid with mucous flakes, giving it the characteristic “rice-water” appearance.
  • Vomiting occurs, initially expelling food and later becoming restricted to rice-water-like fluid.
  • Severe cramps develop in the abdomen and limbs due to salt loss.

Stage II:

  • Dehydration and collapse occur during this stage.
  • The body becomes cold, and the skin appears dry and inelastic.
  • Blood pressure drops, sometimes becoming unrecordable.
  • The pulse becomes rapid and weak.
  • Urine production stops, and the patient may be at risk of shock.

Stage III:

  • This stage marks the recovery phase, which can happen spontaneously or with treatment.
  • Diarrhea decreases, allowing the patient to tolerate fluids.
  • The general condition of the patient rapidly improves.

Diagnosis of Cholera

The diagnosis of cholera is based on the following:

  • History: The patient may have a history of travel to an area where cholera is common, or they may have been in contact with someone who has cholera.
  • Symptoms: The patient will typically have watery diarrhea and vomiting. The diarrhea may be so profuse that it can lead to dehydration and shock.
  • Physical examination: The doctor will examine the patient for signs of dehydration, such as dry skin, sunken eyes, and decreased urination.
  • Laboratory tests: The following laboratory tests may be performed to diagnose cholera:
    • Stool culture: This test is used to grow the bacteria in the laboratory.
    • Polymerase chain reaction (PCR): This test is used to detect the genetic material of the bacteria.
    • Rapid diagnostic test (RDT): This test is a rapid way to detect the bacteria.
Prevention of Cholera

Prevention of Cholera

Cholera is a serious disease that can be fatal, but it is preventable. The best way to prevent cholera is to follow proper sanitation practices.

Here are some specific steps you can take to prevent cholera:

  1. Hand hygiene: Always wash hands with water and soap before preparing, serving, or consuming food. Additionally, it is important to wash hands with soap and water after using a latrine.

  2. Safe drinking water: Boil all drinking water or treat it with chlorine. Store the treated water in a clean container to prevent recontamination.

  3. Food safety: Consume food when it is still hot. If consuming raw foods such as fruits and vegetables, ensure they are properly washed, and when possible, peeled before eating.

  4. Food storage: Cover all foods to prevent contamination by dust, house flies, and cockroaches.

  5. Reporting and burial practices: In the unfortunate event of a cholera-related death, report it immediately to health authorities. Burial should take place promptly, and it is crucial to avoid serving food during this time.

  6. Surveillance and reporting: Active surveillance and prompt reporting of suspected cases allow for the rapid containment of cholera epidemics.

  7. Disinfection: Kill the germs by sprinkling germ-killing solutions, such as JIK, on stool or vomitus, as well as on any other materials used by the person suffering from cholera.

  8. Water and sanitation improvement: Enhance water and sanitation infrastructure to reduce the transmission of infection, such as by improving access to clean water sources and implementing proper waste management systems.

  9. Outbreak investigations: Conduct thorough investigations of diarrheal outbreaks to identify the source of contamination and implement appropriate control measures.

  10. Cholera vaccination: Consider immunization with cholera vaccines in areas prone to outbreaks or for individuals at high risk of exposure.

  11. Treatment of malnutrition: Address malnutrition, as individuals with weakened immune systems are more susceptible to severe cholera. Providing adequate nutrition can help improve their overall resilience.

Management and Treatment

Management and Treatment

  1. Patient admission: The patient can be admitted to temporary hospitals, schools, or churches. Cholera beds with a central hole are used, allowing continuous stools to pass into a calibrated bucket containing a disinfectant.

  2. Oral Rehydration Solution (ORS): ORS is the primary treatment for cholera. It is recommended for rehydrating patients and replenishing electrolytes lost through diarrhea. In cases of severe dehydration, intravenous Ringer’s lactate or normal saline, along with ORS, may be administered. The patient should be reassessed every one to two hours, and hydration should be continued. If there is no improvement in hydration, the intravenous drip rate may be increased. During the first 24 hours of treatment, the patient may require 200ml/kg or more of fluid. If hydration improves and the patient is able to drink, switching to ORS solution is recommended.

  3. Nasogastric tube: In young children, a nasogastric tube can be used to administer fluids if necessary, ensuring adequate hydration.

  4. Antibiotics: In certain cases, antibiotics may be prescribed. Doxycycline 300mg or ciprofloxacin as a single dose can be given, but they are contraindicated in pregnancy. For pregnant women, septrin can be used. In children, cotrimoxazole, doxycycline, ciprofloxacin, or erythromycin may be considered based on the specific circumstances.

  5. Hypoglycemia management: If hypoglycemia is present, intravenous dextrose should be administered to correct low blood sugar levels.

  6. Zinc supplementation: Zinc supplementation is effective in treating and preventing diarrhea, especially among children. It can be provided to aid in recovery.

  7. Isolation and infection control: Patients should be isolated to prevent the spread of infection, as stools and vomit are highly infectious. Proper disposal of stools and vomit should be carried out, preferably into a pit latrine.

  8. Equipment and instrument disinfection: Hospital equipment should be cleaned with a disinfectant such as JIK. Instruments can be cleaned with JIK or sterilized to prevent the transmission of the infection.

  9. Fluid balance chart: A fluid balance chart should be instituted to monitor the patient’s hydration status closely.


  • Shock
  • Electrolyte imbalance
  • Acute renal failure
  • Convulsions/Fits
  • Anaemia
  • Coma
Related Question

a) List 5 cardinal signs and symptoms of cholera.

b) Outline 10 specific nursing care in an outbreak of cholera.


a) Five cardinal signs and symptoms of cholera include:

  1. Watery diarrhea, sometimes in large volumes.
  2. Nausea and vomiting.
  3. Dehydration.
  4. Rice-water stools.
  5. Loss of skin elasticity.

b) Ten specific nursing care measures in an outbreak of cholera:

  1. Wash hands with soap and running water frequently, especially after using the toilet and before handling food.
  2. Advise people to drink only safe water, such as bottled water or water that has been boiled.
  3. Encourage individuals to consume food that is fully cooked and hot, and to avoid street vendor food whenever possible.
  4. Discourage the consumption of sushi, as well as raw or improperly cooked fish and seafood.
  5. Monitor intake and output, taking note of the number, character, and amount of stools.
  6. Promote the use of latrines or proper disposal of feces, emphasizing not to defecate in any body of water.
  7. Ensure that any articles used are properly disinfected or sterilized before use.
  8. Maintain strict asepsis during dressing changes, wound care, intravenous therapy, and catheter handling.
  9. Practice hand hygiene by washing hands or using hand sanitizer before and after having contact with the patient.
  10. Implement proper waste management procedures, particularly for human excreta.

Cholera Read More »

Gastroenteritis (GE)

Gastroenteritis (GE)

Gastroenteritis is a medical condition characterized by inflammation of the gastrointestinal tract that involves both the stomach (gastro-) and the small intestine (entero-), resulting in some  combination of diarrhea, vomiting, and abdominal pain and cramping.  

The severity of infectious gastroenteritis depends on the immune system’s ability to resist the  infection.  

Electrolytes (mainly sodium and potassium) may be lost as the infected individual vomits and  experiences diarrhea.  


Causes of Gastroenteritis

  1. Viruses 
  •  Rotavirus, norovirus, adenovirus, and astrovirus are known to cause viral gastroenteritis. 
  •  Rotavirus is the most common cause of gastroenteritis in children. 
  •  Norovirus  is the leading cause of gastroenteritis among adults, causing greater than 90%  of outbreaks.
  1. Bacteria 
  • In the developed world Campylobacter jejuni is the primary cause of bacterial GE. 
  • Escherichia coli 
  •  Salmonella, Shigella, and Campylobacter species. 
  • Salmonella is contracted by ingesting the bacteria in contaminated food or water and by  handling poultry. 
  • Campylobacter occurs by the consumption of raw or undercooked poultry meat and other  foods. It is also associated with unpasteurized milk or contaminated water.  
  • Clostridium difficile is an important cause of diarrhea that occurs more often in the elderly. It is a common cause of diarrhea in those who are hospitalized and is frequently  associated with antibiotic use. 
  •  Staphylococcus aureus infectious diarrhea may also occur in those who have used  antibiotics. 
  1. Parasites 

A number of protozoans can cause gastroenteritis – most commonly: Giardia lamblia 

  • Entamoeba histolytica 
  • Cryptosporidium 
  1. Non-infectious causes 
  • Medications like NSAIDs 
  • Certain foods such as lactose (in those who are intolerant). 
  • Crohn’s disease.
transmission of gastroenteritis.


The transmission of germs occurs through the feces or vomit of individuals infected with the illness. Gastroenteritis can be spread through the following means:

  • Consuming untreated or unboiled water from rivers, streams, lakes, ponds, or unprotected springs.
  • Eating cold food that has been exposed to dust, flies, or cockroaches.
  • Neglecting to wash hands with soap and water after using a latrine.
  • Eating unwashed fruits and vegetables.
  • Serving food and drinks in dirty containers.
  • Storing drinking water in unclean containers.
  • Improper disposal of feces.
  • Presence of open rubbish in areas that attract flies and cockroaches.

Signs and Symptoms:

The primary symptom is diarrhea, often accompanied by vomiting. Infected individuals may notice the presence of blood or mucus in their stools. Crampy abdominal pain is a common occurrence, which may temporarily ease after passing stool. There may be a low-grade fever, headache, and body aches. Symptoms of dehydration may include:

  • Muscular cramps, sunken eyes, decreased urine output, dry mouth and tongue, weakness, and irritability. In severe cases, adults may experience symptoms such as fatigue, dizziness or lightheadedness, headache, weakness, confusion, rapid heart rate, coma, and significantly reduced urine production.


  • Gastroenteritis is diagnosed clinically, based on a person’s signs and symptoms.
  • Stool cultures should be performed especially in those with blood in the stool.


  • Gastroenteritis is usually an acute and self-limiting disease that does not require medication.
  • The preferred treatment in those with mild to moderate dehydration is oral rehydration therapy (ORT).
  • Intravenous delivery may be required if there is a decreased level of consciousness or if dehydration is severe.
  • Plain water may be used if more specific and effective ORT preparations are unavailable or not palatable.
  • A nasogastric tube can be used in young children to administer fluids if necessary.
  • Institute a fluid balance chart.
  • Metoclopramide may be helpful in some children, and butylscopolamine is useful in treating abdominal pain.
  • Fermented milk products (such as yogurt) are similarly beneficial.
  • Zinc supplementation is effective in both treating and preventing diarrhea among children.
  • Antibiotics are not usually used for gastroenteritis, although they are sometimes recommended if symptoms are particularly severe or if a susceptible bacterial cause is isolated or suspected.
    • If antibiotics are to be employed, a macrolide (such as azithromycin) is preferred. Metronidazole or Tinidazole is used if the cause is protozoa.
  • Isolation of the patient to prevent cross-infection.
  • Proper disinfection and disposal of stool and vomit.
Prevention and Control of gastroenteritis.

Prevention and Control:

  • Always wash hands with water and soap before preparing, serving, or eating food.
  • Always wash hands with soap and water after using a latrine.
  • Boil all drinking water or treat it with chlorine. Store it in a clean container.
  • Consume food while it is still hot.
  • Ensure that raw foods such as fruits and vegetables are properly washed and, whenever possible, peeled before eating.
  • Cover all foods to prevent contamination by dust, house flies, and cockroaches.
  • In the event of a person’s death due to diarrhea, report it immediately to the health authorities.
  • Kill germs by using germ-killing solutions like JIK (bleach) on stool or vomit and on all other materials used by the person suffering from diarrhea.
  • Improve water and sanitation to reduce the transmission of infection.
  • Conduct investigations of diarrheal outbreaks.
  • Treat other infections such as typhoid, dysentery, etc.
  • Address and treat malnutrition.
  • Consider immunization with Rota vaccine, which provides protection against rotavirus, a common cause of gastroenteritis.

Gastroenteritis (GE) Read More »

Introduction to communicable diseases

Introduction to communicable diseases

Communicable diseases, also known as infectious diseases or transmissible diseases are diseases  that spreads from one person or animal to another or from a surface to a person

Communicable diseases occur at all age groups outmost serious in childhood due to intensive exposure and poorly developed immunity. These diseases are to a great extent preventable

In countries where the disease have been largely prevented, other conditions like accidents, and degenerative and malignant diseases that occur at an old age have become the commonest, the process known as epidemiological transmission

Tropical countries, Uganda, inclusive have continued to struggle with poverty related diseases that occur at an old age which include: diarrhea, parasite infestations, respiratory infections, immunizable childhood infections, eye infections and malnutrition. These countries are at the same time facing steady increase of diabetes, CVA, rheumatic conditions and cancer

Communicable’ diseases are divided into 

  • Contact contagious diseases
  • STDs and HIV/AIDs
  • Vector borne diseases
  • Diseases related to contaminated water and food
  • Airborne diseases
  • Blood borne diseases
  • Diseases from the animals and their products
  • Helminthic diseases

Some Communicable diseases and there causative agents.

Causative OrganismDisease/Infection
Rabies virusRabies
Influenza A virusAvian influenza (Bird flu)
Vibrio choleraeCholera
Plasmodium speciesMalaria
Severe acute respiratory syndrome coronavirus (SARS-CoV)Severe acute respiratory syndrome (SARS)
Trypanosoma speciesTrypanosomiasis
Tsetse flySleeping sickness (African trypanosomiasis)
Wuchereria bancroftiElephantiasis
Dracunculus medinensisGuinea worm disease
RotavirusDiarrhea (caused by rotavirus)
Mumps virusMumps
Human immunodeficiency virus (HIV)HIV/AIDS
Varicella-zoster virusChickenpox
Measles virusMeasles
Yellow fever virusYellow fever
ArbovirusesArboviral diseases
African swine fever virusAfrican swine fever
Brucella speciesBrucellosis
Salmonella enterica serovar TyphiTyphoid fever
Schistosoma speciesSchistosomiasis
Shigella speciesDysentery
Bacillus anthracisAnthrax

Why are communicable diseases important in Africa?  

  1. Many of them are very common 
  2. Some of them are very serious and cause death and disability 
  3. Some of them cause widespread outbreaks of the disease- epidemics 4. Many of them are preventable by fairly simple means 
  4. Many are particularly serious and more common in infants and children. 

Organisms and agents of disease 

The living organisms that cause communicable diseases are of different sizes and sorts. The largest, like tape or filarial worms are visible to the eyes. They are made of many cells and  are called metazoa.  

Complicated but single celled organisms like malaria parasites and amoeba are called protozoa.  They are smaller and can only be seen when magnified with a microscope. Smaller still are bacteria which are simple, single cell, best seen under a microscope after they  have been stained with dyes. 

Rickettsiae and chlamydiae are smaller and can only multiply within cells. Smallest of all are the viruses. These cannot be seen with an ordinary microscope.

Epidemiological Triad

Patterns of communicable diseases 

Different diseases are common in different places and different times. To understand why this  happens we need to consider the living organisms of disease- the agent; the people they infect the host and the surrounding in which they live- the environment

The agents need a suitable environment in which to grow and multiply and must be able to  spread and infect other hosts. If they do not succeed in doing this, they die out.

There is therefore a balance between the agent, the host and the environment which can change  and be made to change in different ways.

epidemiological triad

Hosts (people) are affected by environment, for example, they may live in a hot climate in which  there many mosquitoes. But people can also change this environment by draining swamps,  changing the vegetation and adding competing hosts such as animals. 

Similarly, the environment can affect the agent, for example, the altitude and the temperature  for malaria. 


Infectious disease 

An infectious disease is an illness due to a specific infectious agent or its toxic products that arise  through a transmission of that agent or its products from an infected person, animal or reservoir  to a susceptible host, either directly through an intermediate plant or animal host, vector or inanimate environment. 


Infection is the entry and development of an infectious agent in the body accompanied by an  immune response. 


Manifestation of infection through symptoms and signs 


Someone who has met with an infectious agent in a way that is known to cause disease 


Colonization is the presence of a replicating microorganism without clinical or subclinical  infection or disease. No immune response. 


Carrier is a person that harbours a specific infectious agent in the absence of clinical disease and  serves as a potential source of infection.


The reservoir of infection is the animal or place in which a particular organism usually lives and  multiplies. Most of the important communicable diseases humans are the main reservoirs. 

Route of transmission 

The route of transmission is the way in which an organism leaves the infected host or source and  travels to a new susceptible person. 


The source of infection is the animal or place from which the particular organism spreads to its  new host. 

Incubation period 

The incubation period is the time between infection and the appearance of signs and symptoms  of illness. 


Epidemiology is the study of the distribution and patterns of health events, health characteristics  and their causes or influences in a well defined population. Or 

It is a branch of medicine that deals with the study of the causes, distribution and control of  diseases in the population. 


It means the disease is present in the community at all times but in a relatively low frequency Something that is endemic is typically restricted or peculiar to a locality or region. For example  malaria is endemic in some areas of Africa. 


An epidemic is a sudden severe outbreak of an infectious disease that spreads rapidly within a  region or group, affecting a large proportion of people. 


A pandemic occurs when an epidemic becomes widespread and affects a whole region, a  continent or the entire world. 

Clinical disease 

A clinical disease is a disease which has physical manifestations (clinical signs and symptoms). 

Susceptible host 

A susceptible is someone that is exposed to an infectious disease. 


A vector is an animal, usually an insect that transmits parasitic microorganisms from person to  person or from infected animals to human beings. 

Transmission cycle 

The transmission cycle describes how organisms grow, multiply and spread. In some cases humans may be the only host, in which case the infection spreads directly from  person to person, e.g. measles. In other cases, humans are the final hosts from whom the  organism has no chance to pass further, e.g. tetanus. 


There are three parts of a transmission cycle for an agent or organism: 

Source —-> Transmission  —-> Susceptible Host 


The source of an infection can be an infected person or animal, or soil. People and animals may  have clinical disease, subclinical disease or be carriers. 


The main routes of transmission are: 

  • Direct contact (skin, mucous membrane, sexual intercourse) 
  • Vector transmission 
  • Fecal contamination of soil, food and water which are ingested. 
  • Contact with animals or their products (e.g. biting) 
  • Airborne transmission (inhalation) 
  • Transplacental (mother to child) transmission 
  • Blood contact (injections, surgery, blood transfusion) 

Susceptible Host 

A susceptible host is one with low resistance to a particular infection. Low resistance may be due  to: 

  •  Not having met the organism before and therefore not having any immunity to it. For  example, at the age of 6-12 months, a child loses the passive immunity against measles  which was acquired from the mother during pregnancy. When in contact with another child who has measles, the child will develop the disease because of no immunity against  measles 
  •  Having another serious illness like AIDS at the same time. Such people have a higher risk  of developing tuberculosis. 
  •  Malnutrition which can make the infection worse. 

Principles of communicable disease control and prevention 

The aim of control is to tip the balance against the agent. This may be done by: 

  1. Attacking the source 
  2.  Interrupting route of transmission 
  3.  Protecting the host 

Attacking the Source 

Interrupting Transmission 

Protecting the Host


Environmental sanitation 



Personal hygiene 


Reservoir control 

Vector control 

Personal protection


Disinfection and sterilization 

Better nutrition 

Introduction to communicable diseases Read More »

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