Paper II
Question
Nipah virus – modes of transmission and outbreak prevention. (1+3)
Answer
Modes of transmission of Nipah virus: fruit bats (genus Pteropus) are the natural reservoir. Transmission to humans occurs via: direct contact with bat excreta/secretions; consumption of raw date palm sap contaminated by bat saliva/urine during nocturnal sap collection; contact with infected intermediate hosts, classically pigs; and human-to-human transmission via close contact with an infected patient’s bodily fluids — a genuinely important feature distinguishing Nipah virus from Japanese Encephalitis (where humans are dead-end hosts), and one that makes healthcare-associated transmission a real concern.
Outbreak prevention:
- Avoiding consumption of raw date palm sap, and covering sap collection containers to prevent bat access/contamination — a key, specifically targeted measure given the sap-consumption transmission route.
- Reducing bat-human contact — avoiding handling of sick/dead bats or fruit that may have been partially eaten by bats, and avoiding areas with known bat roosting sites during outbreaks.
- Strict infection control and isolation precautions for suspected/confirmed cases (given the genuine human-to-human transmission risk), including barrier nursing and appropriate PPE for healthcare workers.
- Contact tracing and quarantine of individuals exposed to a confirmed case.
- Avoiding contact with sick pigs/other potentially infected intermediate hosts in outbreak-affected areas.
- Public health messaging and community education in endemic/outbreak-prone regions (e.g., Kerala), given the disease’s high case fatality and the entirely supportive nature of available treatment (no specific antiviral or licensed vaccine exists for human use), making outbreak containment through these public-health measures the central management strategy.
- Surveillance systems to enable early detection and rapid response to emerging clusters, given Nipah virus’s status as a WHO priority pathogen for epidemic preparedness.