Written By: Satata Karmakar | Updated : February 23, 2026 1:25 PM IST
Medically Verified By: Dr. Shibu Varkey
Monkey Fever
Kyasanur Forest Disease (KFD), commonly called monkey fever, is a viral infection transmitted to humans through the bite of infected ticks, mainly the Haemaphysalis species. The virus naturally circulates among monkeys and small mammals, and humans contract it accidentally when visiting or working in forests.
The disease was first identified in 1957 in the Kyasanur forest of Karnataka, hence its name. While it is named "Monkey Fever," it is important to note that monkeys are not the source of infection for humans they act as hosts in the virus's natural cycle. Infected ticks that have fed on these monkeys transmit the virus to humans.
In an exclusive interaction with TheHealthSite.com, Dr. Shibu Varkey, Regional Medical Director Tamil Nadu; Maxivision Super Speciality Eye Hospitals, said, "KFD is a tick-borne viral illness, and some patients may experience redness, watering, light sensitivity, eye pain, or temporary blurred vision during the fever phase due to systemic inflammation, though in most cases, it does not cause serious damage to the eyes. These symptoms are usually mild and resolve with recovery, and in rare cases, especially if the infection affects the nervous system, patients may experience double vision or other more significant visual disturbances. Recently, we have evaluated 01 such cases with eye-related issues caused by KFD. While severe complications are uncommon, early ophthalmic assessment is advisable if visual symptoms persist, to ensure timely care and prevent avoidable complications."
KFD has an incubation period of 3 8 days, during which individuals may not show any symptoms. When symptoms appear, they often include:
Most people recover within 1 2 weeks, but severe cases can lead to hemorrhagic complications and death, as seen in this first reported fatality of the year.
KFD is considered dangerous for several reasons:
The virus primarily spreads through tick bites, but it can also be transmitted if an individual comes into contact with the blood or tissues of infected monkeys. Human-to-human transmission is extremely rare.
Ticks are most active during monsoon and post-monsoon seasons, which is why outbreaks often occur between November and May in endemic regions.
Authorities have intensified monitoring in Karnataka, including vaccination campaigns, public awareness drives, and tick control measures. Residents and visitors in forested regions are advised to:
The KFD vaccine is available in endemic zones and is recommended for individuals above one year of age, with booster doses for ongoing protection.
Currently, there is no specific antiviral treatment for KFD. Management mainly involves supportive care:
The first death in 2026 serves as a stark reminder of the ongoing threat of KFD in Karnataka. Health authorities are increasing surveillance, vaccination, and public awareness, especially in forested areas where human-tick interaction is high.
It also highlights the need for prompt medical care and early detection. Anyone showing symptoms after forest exposure should seek medical attention immediately, rather than assuming it is a mild viral illness.
As KFD continues to pose a threat in endemic regions, staying informed, following preventive measures, and seeking early treatment remain the most effective ways to protect yourself and your family.
