Kyasanur Forest Disease: a Status Update

Abstract

Kyasanur Forest Disease (KFD) is an emerging zoonotic viral tick borne disease affecting mainly monkeys. The etiological agent of KFD is Kyasanur Forest Disease virus (KFDV), a RNA virus of the genus Flavivirus, family Flaviviridae. The natural host of KFDV mainly involves wild primates and various tick species of genus Haemaphysalis. In enzootic areas, the KFDV was maintained and circulated in small mammals especially rodents, shrews, ground birds and ticks. KFD is endemic in 5 areas of Karnataka, India mainly Shimoga, Chikkamagalore, Uttara Kannada, Dakshina Kannada, and Udupi. KFD has been reported also from Tamil Nadu and Kerala. A variant of KFD has been isolated from Saudi Arabia and China. The various isolates of KFDV from India, Saudi Arabia, and China share a recent common ancestor. Though the prevalence of KFD is reported from few areas, chances of existence of virus outside these foci can't be eliminated. KFD should be included in differential diagnosis of diseases in other areas of Asia and Middle East The clinical manifestation of disease ranges from haemorrhagic phase to neurological manifestations. Diagnosis of KFD is mainly by virus isolation or by various serological detection methods. Molecular diagnostic methods such as RT-PCR, real time PCR are also available. A formalin inactivated tissue culture vaccine is available for prophylaxis. Other control strategy includes wearing protective clothing while handling infectious materials and tick control. Thorough knowledge of transmission of disease is very essential in control/prevention programmes. There is a requirement of better diagnostic methods, tick control strategies, public awareness, more area coverage of immunization and regular revaccination.