MCQ of the Day: 31 October 2026

Answer: B. Pteropus fruit bats. Acute encephalitis with respiratory involvement, high fatality, human-to-human spread to a carer, and a link to fruit contaminated by bat saliva or urine point to Nipah virus (genus Henipavirus, family Paramyxoviridae). Fruit bats of the genus Pteropus are the natural reservoir. Kerala has had repeated outbreaks since 2018, and in Bangladesh and West Bengal infection is linked to drinking raw date palm sap. Diagnosis is by RT-PCR on throat swab, CSF, urine or blood; it is a BSL-4 pathogen, so samples go to the ICMR-NIV, Pune, network.

A. Pigs were the amplifying (intermediate) host in the 1998–99 Malaysian outbreak, not the natural reservoir.

C. Culex mosquitoes transmit Japanese encephalitis and West Nile viruses; Nipah has no arthropod vector.

D. Rodents are reservoirs for leptospirosis, plague and hantaviruses, not henipaviruses.