Vector control scientist Padma Shri P.K. Rajagopalan was among the first to identify Kyasanur Forest Disease (KFD) in Shivamogga as a new zoonotic disease in 1957. His pioneering research work, in the form of dozens of papers, between 1957 and 1970 continues to form the base of much of our understanding of the tick-borne disease, which has killed nine people and infected more than 90 persons in villages in Shivamogga this year. The 89-year-old biologist, who continues to write actively on KFD, spoke to The Hindu recently. Excerpts:

How did you become involved in the investigations into monkey fever in 1957?

I was then a 26-year-old field entomologist and was part of a field station in Akividu (Andhra Pradesh) to study whether migrating birds were bringing Japanese encephalitis to India. We got a telegram from the Virus Research Centre, Pune, asking me to move immediately to Sagar (Shivamogga). There had been reports of monkey deaths and there were fears that yellow fever had broken out.

Our first task was to get mosquitoes and test them for the virus. People who were sick in the area were brought to Sagar, where supportive treatment was given. Their blood, as well as organs from the deceased, were sent to the Rockefeller Foundation’s New York laboratory. The virus was isolated and identified as related to Omsk Hemorrhagic Fever, which is a tick-transmitted virus. The search for mosquitoes was given up on. Field staff were given yellow fever vaccination, but within 10 days even the vaccinated staff came down with fever. Ticks were collected from the forest floor as well as monkeys and tested, and sure enough the KFD virus was isolated. Kyasanur Forest Disease was named after the place where the first virus isolation was made.

Initial theories suggest they could have come through birds or as a part of a series of viruses brought through the Silk Road.

All kind of wild theories were floated. The idea of birds as carriers was refuted after a two-year study in which over 8,000 birds were tested for antibodies, virus isolation and tick ectoparasites. Antibodies were found only in some ground-moving birds, but no non-indigenous tick species was found on them. This was proof that the virus was not introduced by migratory birds.

My opinion is the virus is indigenous and present in the ecosystem. I feel that the insectivore bat species Rhinolophus rouxi and its ectoparasite Ornithodoros chiropterphila (which was discovered by Dr. Rajagopalan) are the most important source. An infection is like a flower: it sprouts up when conditions are favourable.

It is often said that KFD outbreaks are aggravated by human activity within forests...

They flare up because of various ecological changes — development works, agricultural practices, and climate, among other things. Ticks are very slow moving and humans get the infection when they frequent a pocket with infected ticks. If a man does not go there, there is no human case.

The KFD field station is critical for surveillance of the disease and research into vaccinations. But it seems to be non-operational since you left in 1970.

Mysore state then had the best primary healthcare system in all of India. The health infrastructure at the lower levels (health inspectors and midwives) knew almost every villager. I could organise an excellent information system which included prompt messages about monkey deaths. Unfortunately, this is no longer there. The government has done no work on KFD studies. A virus diagnostics laboratory was established in Shivamogga, but every year the officer in charge is shifted. There must be staff to do surveillance.

It is also better to take decisions at the local, district and State levels than depend on Central agencies. They must create the infrastructure for this. You have to treat every village as a new centre for the epidemic.

Do you think enough research is being done locally to develop a better vaccine?

The vaccine being used is useless. The three-dose vaccine is impractical to administer and its efficacy has been doubted. A whole set-up is necessary. It costs a lot of money, but this is a policy decision. As you know in India, health is given the lowest priority. There is not going to be a single-dose KFD vaccine available in the near future.