The epizootics of Kyasanur Forest disease in wild monkeys during 1964 to 1973

Abstract

In the Kyasanur Forest disease area two species of wild monkeys, Presbytis entellus and Macaca radiata, succumb to the natural infection with Kyasanur Forest disease (KFD) virus (family Flaviviridae). Between October 1964 and September 1973, 1046 monkeys (860 P. entellus and 186 M. radiata) died. Of these, KFD virus was isolated from 118 P. entellus and 13 M. radiata. Maximum mortality of monkeys was reported during December through May coinciding with the season of activity of immature stages of Haemaphysalis ticks, incriminated vectors of KFD. The epizootic showed an initial spread of the disease to the areas contiguous with the original focus of infection. This was followed by the recognition of epizootics and epidemics in three new foci, removed from the original focus, by the end of 1973. It was also observed that, in certain localities in the original focus, KFD virus activity persisted over several years.

Kyasanur forest disease: an epidemiological view in India

“…KFD epizootic is initially characterised by the spread of the disease to the areas contiguous with the original focus of infection. [44].…”

Kyasanur Forest Disease: a Status Update

“…Outbreaks in human population of Shimoga district, Mysore State were reported from (Upadhyaya et al, 1975. Similarly reports of non human primates are from 1957 -1964 by Goverdhan et al, (1974) and 1964-1973by Sreenivasan et al, (1986. Report of Upadhyaya et al (1975), mainly centered on endemic areas, whereas the report of Sreenivasan (1986) spread out the area to non endemic places also and reported 1046 monkey mortality during the peak season of tick activity.…”

“…In every season of epidemic, around 500 cases are reporting from these areas (Sreenivasan et al, 1986;Pattnaik, 2006). Outbreaks in human population of Shimoga district, Mysore State were reported from (Upadhyaya et al, 1975.…”

“…In primate host, black-faced langurs were found highly vulnerable to the virus (Sreenivasan et al, 1986). Tick population hike during dry season (December to May), results in all major epizootics during this period (Rajagopalan et al, 1968a, b).…”

“…Domestic ruminants can maintain the infected tick population for long time. The ticks of genus Haemophysalis, mainly Haemophysalis spinigera act as a major vector for KFD (Sreenivasan et al, 1986). Wide spread distribution of this species of tick in forests especially tropical and deciduous of southern and central India.…”