Kyasanur forest disease

Definition

A tick-borne viral hemorrhagic fever endemic to the southwestern Indian state of Karnataka, caused by Kyasanur Forest disease virus (KFDV), a member of the family Flaviviridae. The disease is maintained in forest ecosystems where hard ticks (family Ixodidae) serve as both vectors and reservoirs, transmitting KFDV to humans, monkeys, and other mammals through infected bites. Outbreaks typically correlate with nymphal tick activity during the dry season (January–June) and are associated with forest fragmentation, agricultural encroachment, and human exposure to tick-infested habitats.

Etymology

Named for the Kyasanur forest area in Shimoga district, Karnataka, India, where the disease was first identified in 1957 during an epizootic among wild monkeys.

Example

Field entomologists conducting surveillance for Kyasanur forest disease in the Western Ghats collect questing nymphs of Haemaphysalis spinigera from leaf litter and vegetation, then test pools by RT-PCR to detect KFDV and map transmission risk across forest-agriculture interfaces.

Synonyms

• KFD

Related Terms

• Tick-borne encephalitis
• Omsk hemorrhagic fever
• Flaviviridae
• Ixodidae
• vector-borne disease
• Zoonosis
• viral hemorrhagic fever
• disease ecology
• acarology

Usage Notes

The term refers specifically to the human/animal disease syndrome, not the virus itself (KFDV). Specialists distinguish KFD from other tick-borne flaviviral hemorrhagic fevers such as Omsk hemorrhagic fever (Russia) and Alkhurma hemorrhagic fever (Saudi Arabia) by geographic range, primary vector species, and minor genetic divergence. Despite its name, KFD is not restricted to forest habitats; transmission occurs at forest edges, plantations, and recently cleared areas where tick hosts congregate. Vaccination and personal protective measures against tick bites are the primary control strategies; no specific antiviral therapy exists.