On Aug. 23, 2024, the World Health Organization announced that between early June and 15 August 2024, the Ministry of Health and Family Welfare of the Government of India had reported 245 cases of acute encephalitis syndrome (AES) including 82 deaths. Of these, 64 are confirmed cases of Chandipura virus (CHPV) infection.

CHPV is endemic in India, with regular outbreaks. However, the current outbreak was the largest in twenty years. CHPV is a member of the Rhabdoviridae family and is known to cause sporadic cases and outbreaks of AES in western, central and southern parts of India, especially during the monsoon season. It is transmitted by vectors such as sandflies, mosquitoes and ticks.