Animal · Human · Environment
Vector-borne · Forest-interface
Kyasanur Forest Disease (KFD)
A tick-borne haemorrhagic fever caused by KFD virus (Flaviviridae), endemic to the Western Ghats and adjacent forest belts of India. Also known locally as "monkey fever".
Pathogen
KFD virus (Flaviviridae)
Vector
Hard ticks (Haemaphysalis spinigera)
Incubation
3–8 days
CFR
3–10%
Transmission & Risk Groups
Transmitted via the bite of infected hard ticks in forest environments. Primates (langurs, bonnet macaques) serve as amplifying hosts; mass die-offs in monkeys often signal an active transmission cycle. Humans are dead-end hosts. Person-to-person spread does not occur.
Highest-risk groups
- Forest dwellers & tribal communities
- Agricultural workers near forest edges
- Hunters, livestock handlers, fuelwood collectors
- Forest department staff & researchers
- Pilgrims & eco-tourists in endemic zones
Symptoms (humans)
- Sudden high fever, chills, severe headache
- Severe muscle pain, vomiting, photophobia
- Bleeding tendencies (nose, gums, GI tract)
- Biphasic illness: ~15% develop second phase with neurological signs
Prevention & Control
- Vaccination: formalin-inactivated tissue-culture vaccine (NIV Pune) administered to populations in endemic zones — primary dose, booster at 4 weeks, then annual.
- Personal protection: DEET repellents, light-coloured full-sleeve clothing, body checks after forest exposure.
- Monkey carcass surveillance: mandatory reporting and safe disposal — major early warning signal.
- Vector control: spraying of dust at carcass sites and forest paths with limited effectiveness.
- Health education: targeted to tribal hamlets, eco-tourists, forest staff during high-risk season (Nov–May).
- Risk mapping: link forest cover, primate activity, livestock grazing, and human movement data — One Health priority.
Cases by District (last 7 days)
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