Waterborne & Foodborne Diseases

Question 1

What is the causative organism of cholera?

Answer 1

Vibrio cholerae* (serogroups O1 and O139).

Question 2

Describe the chain of infection for cholera.

Answer 2

1. Reservoir: Contaminated water sources (e.g., rivers, lakes).
2. Transmission: Ingestion of contaminated food/water.
3. Portal of Entry: Mouth.
4. Susceptible Host: Individuals with poor hygiene, malnutrition, or weakened immunity.

Question 3

What are the hallmark symptoms of cholera?

Answer 3

Profuse “rice-water” diarrhea, vomiting, dehydration (rapid heart rate, sunken eyes, dry skin).

Question 4

How is cholera treated?

Answer 4

• Oral rehydration solution (ORS) or IV fluids for severe dehydration.
• Antibiotics (doxycycline, azithromycin) to reduce severity.

Question 5

List three preventive measures for cholera.

Answer 5

• Safe water and sanitation (e.g., treated water, improved sewage systems).
• Proper food handling (cook thoroughly, avoid raw seafood).
• Cholera vaccination for high-risk populations.

Question 6

What are the three types of causative agents for dysentery?

Answer 6

1. Bacterial: Shigella spp., Campylobacter jejuni.
2. Parasitic: Entamoeba histolytica (amoebic dysentery).
3. Viral: Norovirus, Rotavirus.

Question 7

Explain the chain of infection for dysentery.

Answer 7

1. Reservoir: Contaminated food/water or infected individuals’ feces.
2. Transmission: Fecal-oral route (poor hygiene, contaminated surfaces).
3. Portal of Entry: Mouth.
4. Susceptible Host: Individuals in unsanitary conditions or with weakened immunity.

Question 8

What distinguishes dysentery from typical diarrhea?

Answer 8

Blood/mucus in stools, abdominal cramps, and fever.

Question 9

How is dysentery treated based on its cause?

Answer 9

• Bacterial: Antibiotics (fluoroquinolones, azithromycin).
• Amoebic: Antiparasitics (metronidazole).
• Supportive care: Hydration, IV fluids for severe cases.

Question 10

What prevents dysentery outbreaks?

Answer 10

• Handwashing with soap.
• Safe food/water consumption (cooked food, treated water).
• Improved sanitation (proper waste disposal).

Question 11

What virus causes hepatitis A, and to which family does it belong?

Answer 11

Hepatitis A virus (HAV), family Picornaviridae.

Question 12

Outline the chain of infection for hepatitis A.

Answer 12

1. Reservoir: Infected humans (virus in feces).
2. Transmission: Fecal-oral route (contaminated food/water or close contact).
3. Portal of Entry: Mouth.
4. Susceptible Host: Unvaccinated individuals.

Question 13

What are the key symptoms of hepatitis A?

Answer 13

Fatigue, jaundice (yellow skin/eyes), nausea, dark urine, pale stools.

Question 14

Is there a cure for hepatitis A? How is it managed?

Answer 14

• No cure: Self-limiting infection.
• Supportive care: Rest, hydration, nutrition, avoiding alcohol.

Question 15

How can hepatitis A be prevented?

Answer 15

• Vaccination (recommended for travelers/high-risk groups).
• Hygiene (handwashing after bathroom use).
• Safe food/water practices.

Question 16

What links cholera, dysentery, and hepatitis A?

Answer 16

Transmission via fecal-oral route, reliance on poor sanitation, and preventable through hygiene/vaccination.

Question 17

Why are these diseases more prevalent in areas with poor sanitation?

Answer 17

Contaminated water, inadequate sewage systems, and lack of hygiene facilitate pathogen spread.

Question 18

Name one vaccine-preventable disease in this category.

Answer 18

Hepatitis A and cholera (vaccines available).