Which of the following States was in the news for the outbreak of Nipah virus disease in May-June, 2018?

Kerala is correct. The May 2018 Nipah outbreak began in Perambra and Kozhikode in north Kerala, and by June it had caused several deaths. The state health department, with central agencies, ran contact tracing, isolation and containment. Nipah is a zoonotic virus. Fruit bats of the Pteropus genus are its natural reservoir, and humans get infected through contaminated date palm sap, partly eaten fruit, or close contact with infected people.

Why the others fail:

• Bihar is associated with Acute Encephalitis Syndrome (AES) outbreaks, which are a different disease, not Nipah in 2018.
• Haryana and Gujarat did not report a Nipah outbreak in this period, so neither fits the news reference.

Core concept: zoonoses and One Health surveillance. For Mains, this links to pandemic preparedness, bat-human interface, and the role of district surveillance and the IDSP.

Trap: aspirants mix Nipah with AES or Japanese Encephalitis and pick Bihar or a state that had a different encephalitis story. Link the virus to its reservoir and transmission route, not to a state name.