Every year, between January and May, remote villages along Karnataka's Western Ghats witness something disturbing: monkeys fall dead from trees. Locals call it "monkey fever" — and they know that when the monkeys die, the next victims could be the people who farm, herd, or collect firewood in those forests. In 2026, Karnataka has already recorded its first death from this disease, a 29-year-old man from Shivamogga district. Kyasanur Forest Disease (KFD) is no longer just a jungle health warning — it is spreading to new districts and states, and every Indian living in or visiting forested regions of the Western Ghats should know its signs.
What Is Kyasanur Forest Disease (Monkey Fever)?
Kyasanur Forest Disease (KFD) is a tick-borne viral haemorrhagic fever caused by the Kyasanur Forest Disease virus (KFDV), a member of the Flavivirus family (the same family as dengue and Japanese encephalitis viruses). It was first identified in 1957 in the Kyasanur forest range of Shivamogga (formerly Shimoga) district, Karnataka, making it one of India's few disease discoveries on home soil.
The disease is transmitted to humans through the bite of hard ticks — mainly Haemaphysalis spinigera — that live in the leaf litter and low vegetation of moist deciduous forests. Monkeys (bonnet macaques and black-faced langurs) act as amplifying hosts: when they are infected, tick populations feeding on their blood become highly infectious. A sudden die-off of monkeys in a forest area is the earliest warning signal of a KFD season.
Key facts:
- Case fatality rate: 3–5% with supportive care
- Season: Predominantly November to June, peaking January–March
- No human-to-human transmission — only through infected tick bites
- Persons at highest risk: farmers, forest workers, cattle herders, woodcutters, and tribal communities living near forests
Where Is KFD Found in India?
Once confined to three districts of Karnataka, KFD has been creeping along the Western Ghats for decades.
| State | Affected Districts / Areas |
|---|---|
| Karnataka | Shivamogga, Uttara Kannada, Chikkamagaluru, Dakshina Kannada, Udupi, Belagavi, Kodagu |
| Kerala | Wayanad, Malappuram, Thrissur |
| Tamil Nadu | Nilgiris, Coimbatore |
| Goa | North Goa forest areas |
| Maharashtra | Sindhudurg (Rajapuri) |
India reports approximately 400–500 KFD cases per year, though experts believe under-reporting is significant. The disease is considered notifiable by the National Centre for Disease Control (NCDC). If you live in or plan to visit any forested or scrub area in these states, awareness is essential.
Symptoms: What Monkey Fever Feels Like
KFD has a characteristic two-phase illness pattern that sets it apart from other fevers.
Phase 1 (Days 1–12): The Fever Phase
Symptoms begin abruptly, 3 to 8 days after a tick bite.
| Symptom | Description |
|---|---|
| Sudden high fever | 39°C–40°C (102°F–104°F) with chills |
| Severe headache | Frontal, persistent, often debilitating |
| Intense muscle pain | Particularly in the limbs and lower back |
| Vomiting and nausea | Common from day 2–3 |
| Bleeding manifestations | Nosebleeds, bleeding gums, blood in vomit or stools (days 3–4) |
| Eye redness (conjunctivitis) | Bloodshot eyes with sensitivity to light |
| Abnormal low blood counts | Thrombocytopenia (low platelets) and leucopenia (low WBCs) — detected on CBC |
Most patients improve after the initial 1–2 week fever phase. However, about 10 to 20% go on to a dangerous second phase.
Phase 2 (3–21 days after Phase 1): The Neurological Phase
After a brief apparent recovery, some patients develop a second wave:
- Severe headache and stiff neck — signs of meningeal irritation
- Mental confusion, disorientation, or abnormal behaviour
- Tremors and visual disturbances
- Weakness and fatigue lasting weeks
This biphasic pattern is a hallmark of KFD and distinguishes it from dengue or simple viral fever. The neurological phase carries a higher risk of death and long-term complications.
How Is KFD Diagnosed?
Early diagnosis is critical because supportive care is the only available treatment. If you are in an endemic area with high fever after forest exposure, the following tests are relevant:
Recommended Tests
Complete Blood Count (CBC): Will show low platelets (thrombocytopenia) and low white blood cells (leucopenia) — abnormal findings that prompt further investigation. You can upload your CBC reports to MedicalVault to track trends across visits.
Liver Function Tests (LFT): KFD often causes elevated liver enzymes (SGPT, SGOT), which can appear within the first week. See our LFT guide for context.
Kidney Function Tests (KFT): Renal impairment can develop in severe cases.
Specific Viral Tests (ICMR/NIV Pune):
| Test | Notes |
|---|---|
| RT-PCR (KFDV) | Best in first 5 days of fever; detects viral RNA |
| IgM ELISA | Positive from Day 5–7 onwards; good for late presentation |
| Virus isolation | Done only at BSL-3 labs (NIV Pune) for confirmation |
The National Institute of Virology (NIV) in Pune is the national reference laboratory for KFD testing. Samples must be transported to NIV Pune or designated state labs in Shivamogga for confirmatory testing.
Important: In rural endemic areas, diagnosis is often made clinically (fever + bleeding + low CBC + forest exposure). Do not wait for lab results to begin supportive care.
Treatment: What Doctors Do
There is no specific antiviral drug approved for KFD. All treatment is supportive:
- Intravenous fluids to prevent dehydration and shock
- Platelet and blood transfusions for severe bleeding
- Antipyretics (paracetamol) for fever — aspirin and ibuprofen should be AVOIDED as they worsen bleeding
- Oxygen support and ICU care for respiratory complications
- Monitoring liver, kidney, and blood counts closely
Most patients who receive prompt supportive care in a hospital recover within 2 weeks. Fatalities typically occur in those who present late, are elderly, or develop neurological complications.
The KFD Vaccine: Who Gets It and What's New in 2026?
A formalin-inactivated KFDV vaccine has been available in India since the 1990s and is provided by the Karnataka government to people living in endemic areas. However, this older vaccine has several limitations — it requires multiple doses, has moderate efficacy, and is not widely available outside Karnataka.
In 2026, India launched Phase I clinical trials of a new indigenous KFD vaccine developed through a collaboration between the Indian Council of Medical Research (ICMR) and Indian Immunologicals Limited. This is a two-dose, adjuvanted, inactivated vaccine that completed successful animal studies and has now moved to human trials testing safety and dosage. The goal is a more effective, scalable vaccine that can be deployed across all affected states.
Who Is Currently Eligible for the Existing Vaccine?
The current KFD vaccine is recommended for:
- People living or working in endemic villages of affected districts
- Forest department workers, cattle herders, and plantation workers
- Persons visiting endemic areas for extended periods (wildlife researchers, trekkers staying for weeks)
The vaccine schedule is 0, 1, and 3 months (primary series), with annual boosters for continued risk. It is given free at government health centres in endemic Karnataka districts.
Prevention: How to Protect Yourself
Whether or not a vaccine is available in your area, the following precautions significantly reduce your risk:
Tick Bite Prevention
- Wear protective clothing: Long-sleeved shirts, full trousers tucked into socks, and closed shoes when walking in forests or scrubland
- Use DEET-based repellents on exposed skin and on clothing (follow label instructions)
- Permethrin-treated clothing provides additional protection for extended forest exposure
- Check for ticks after returning from forests — carefully inspect scalp, behind ears, armpits, groin, and backs of knees
- Remove ticks promptly with fine-tipped tweezers, grasping close to the skin. Do not crush ticks with fingers — this can release the virus
After Forest Exposure
- Shower as soon as possible after forest visits
- Wash and dry clothing at high temperature
- Monitor for fever for 2 weeks after potential tick exposure
- Report to a government hospital immediately if fever develops — mention forest exposure and possible tick contact
Keeping Animals Safe
- Cattle and domestic animals can carry ticks that bite humans. Regular acaricide (tick-killing spray) treatment of cattle in endemic areas dramatically reduces tick burden in villages
- Avoid direct contact with sick or dead animals (monkeys, rodents) found in forests
When to See a Doctor: Red Flags
Seek emergency care immediately if you or someone near you develops the following after being in a forested area:
- Fever above 38.5°C lasting more than 2 days
- Nosebleeds, bleeding gums, or blood in stool/urine
- Severe headache with confusion or altered behaviour
- Rapid deterioration, extreme weakness, or fainting
In KFD-endemic districts, always mention recent forest exposure to your doctor — this single detail can change the clinical approach and prevent delayed diagnosis.
Tracking Your Health During and After KFD
If you or a family member has recovered from KFD, monitoring your blood counts and liver/kidney function over the following weeks is important. Recovery can be slow and the neurological phase can be delayed. Using MedicalVault's trend analysis feature to track your serial CBC, LFT, and KFT results in one place helps you and your doctor see if parameters are normalising — without losing track of reports across multiple lab visits.
You may also find our related guides useful:
- Dengue Test Guide — another tick/mosquito-borne fever with similar early symptoms
- Understanding Your CBC Report — how to read the blood counts affected by KFD
- Liver Function Test (LFT) Guide — monitoring liver involvement during recovery
Key Takeaways
- Kyasanur Forest Disease (Monkey Fever) is a tick-borne viral haemorrhagic fever found along India's Western Ghats, with 400–500 cases every year and a 3–5% fatality rate.
- The disease causes a distinctive two-phase illness: initial fever with bleeding, followed by a neurological phase in 10–20% of patients.
- Diagnosis relies on RT-PCR (first 5 days) or IgM ELISA (after day 7) at ICMR reference labs, alongside CBC and liver tests.
- No specific antiviral treatment exists — early hospitalisation and supportive care are the mainstay.
- A formalin-inactivated vaccine is available free of cost in endemic Karnataka districts; a new ICMR-developed vaccine entered Phase I trials in 2026.
- Prevention is highly effective: wear protective clothing, use DEET repellent, check for ticks, and remove them promptly after forest visits.
- If you live in or visit KFD-endemic areas, track your health reports across visits — MedicalVault's family sharing feature makes it easy to manage records for everyone in your household.