Question

Which one or more of the following diseases is/are zoonotic?

• A. Nipah virus infection
• B. Ebola Haemorrhagic Fever
• C. Cholera
• D. Kyasanur Forest Disease

Hint:

Ask whether each pathogen has an animal reservoir it must pass through before infecting humans. Cholera spreads through contaminated water, not an animal host.

Answer 1

The Correct Option is A, B, D

Step 1: Understanding the Question.
A zoonotic disease is one that is caused by a pathogen that normally lives in animals and can jump from an animal host to infect humans. We need to check each of the four diseases and decide whether its causative agent is transmitted from animals to people.

Step 2: Key Concept.
Zoonoses typically have a wild or domestic animal reservoir, and infection reaches humans through direct contact, a vector such as a mosquito or tick, or contaminated animal products. Diseases spread mainly through contaminated water or human to human transmission, with no essential animal reservoir, are not classified as zoonotic.

Step 3: Detailed Explanation.
Option (A): Nipah virus infection. Nipah virus naturally circulates in fruit bats (the reservoir host) and spills over into humans through contact with infected bats, pigs, or contaminated fruit and date palm sap. This is a well documented zoonotic disease, so (A) is correct.
Option (B): Ebola Haemorrhagic Fever. Ebola virus is believed to be maintained in a wild animal reservoir, most likely fruit bats, and it spills over into humans and other primates through contact with infected animals or bushmeat, before spreading further by human to human contact. Because its origin is an animal reservoir, it is classified as zoonotic, so (B) is correct.
Option (C): Cholera. Cholera is caused by the bacterium \(\textit{Vibrio cholerae}\), which spreads mainly through water or food contaminated with human faecal matter, not through an animal reservoir. Since there is no essential animal host driving transmission to humans, cholera is not considered zoonotic, so (C) is incorrect.
Option (D): Kyasanur Forest Disease. This viral haemorrhagic disease is transmitted to humans through the bite of infected hard ticks that normally feed on forest rodents and monkeys, making monkeys and small mammals the animal reservoir. This is a classic tick-borne zoonosis, so (D) is correct.

Step 4: Final Answer.
Nipah virus infection, Ebola Haemorrhagic Fever, and Kyasanur Forest Disease all have animal reservoirs and spread to humans from animals, while cholera does not, so options (A), (B) and (D) are correct.
\[ \boxed{\text{(A), (B) and (D)}} \]