ABSTRACT
Kyasanur Forest disease virus (KFDV) was detected after a new febrile and sometimes fatal disease was described in Shimoga district of Karnataka State in India. Human suspected cases of typhoid occurred at least since 1956 in this area (Rau, 1957). However, serological tests to detect typhoid fever, like Widal or Weil-Felix, turned out to be nonreactive, so the suspected diagnosis of typhoid and typhus seemed unlikely. A eld excursion of the Indian Virus Research Center in March and April 1957 nally discovered a lterable agent from a dead langur (Presbytis entellus) and two dead bonnets (Macaca radiata), which were found near a street along the Kyasanur State Forest (Work and Trapido 1957a). At the same time as human cases of this new severe illness were reported, a large number of sick or dead monkeys had been noticed by the local population. This observation at that time also caused severe concerns of an outbreak of sylvatic yellow fever in India. Later, the lterable agent could be isolated from patients’ blood and organs and the transmission cycle could be explored after a similar virus was isolated from ticks of the genus Haemaphysalis (Trapido et al., 1959). The agent was named Kyasanur forest disease virus after the location of the original discovery. Serological tests revealed that KFDV was a member of the tick-borne virus serocomplex of the group B arboviruses, now the family Flaviviridae.
