The Kyasanur forest disease, also known as monkey fever, was till recently seen only in Karnataka's five endemic districts — Shimoga, Chikkamagalore, Uttara Kannada, Dakshina Kannada and Udupi of Malnad region

It has not only spread to newer areas in Karnataka like Chamrajanagar, but also dispersed to adjoining states like Tamil Nadu and Kerala.

The Indian Council of Medical Research has sounded an alert and surveillance has been stepped up in states that share a boundary with Karnataka that include Maharashtra, Andhra Pradesh, Tamil Nadu and Kerala.

The National Institute of Virology has developed a vaccine for this disease which is available in Karnataka, where in recent years the number of human cases has been occurring.

• The virus that causes KFD or monkey fever is a highly pathogenic member in the family Flaviviridae, which causes dengue and yellow fever. The pathogen was named after the forest area where it was first detected in 1957. Scientists at NIV first found and described the disease as KFD
• Though the virus has been isolated from 16 species of ticks, the species Haemaphysalis spinigera is the major vector
• Monkeys which come in contact with the infected ticks in the forest get the virus and act as the amplifying host. Some small mammals such as rats and shrews are known to act as hosts for the virus. Campers or others passing through the forest get the disease from the bites of infected nymphs of the tick or through contact with the infected monkey or even a monkey which died recently from the infection
• Once infected, timely supportive management is the only treatment mode
• The infection, which starts with high fever and body ache, produces a haemorrhage in the body, similar to that produced by dengue fever, and has a mortality rate of five per cent to 10 per cent