Monkey Fever— Kyasanur Forest Disease
Abstract & Commentary
Synopsis: Kyasanur Forest disease, also known as "monkey fever," is a cause of hemorrhagic fever with late CNS manifestations in a geographically delimited area of India.
Source: Kyasanur Forest Disease—India (Karnataka). ProMED. http://www.promedmail.org.
Indian health officials from Karnataka state (formerly Mysore state) reported 253 cases, including 10 deaths, of Kyasanur Forest disease. Cases were reported from almost 70 villages. Large numbers of monkeys had also died. The state government responded by institution of a vaccination program within a 10-km radius of affected villages. In addition, insecticide spraying within a 5-km radius around dead monkeys was implemented.
Comment by Stan Deresinski, MD, FACP
Investigation of an outbreak of fatal disease in monkeys and men in a forested area within Shimoga District of Karanataka state in western India in 1957 led to the discovery of a novel flavivirus. The virus, a member of the tick-borne encephalitis complex, was given the name Kyasanur Forest disease after the area in which it was discovered.1 This virus has remained localized to subtropical forest in this area where approximately 300-500 cases are identified annually. The case fatality rate is 3-5%. The emergence of this disease may be related to deforestation activities and consequent change in interactions between humans and the natural ecology.
Infected individuals experience the abrupt onset of fever and headache after an incubation period of 3-7 days.2 Myalgias, with severe back and extremity pain, are common. Pulmonary involvement may be heralded by the development of a cough. Hemorrhagic manifestations may ensue. Survivors of this initial phase of hemorrhagic fever may, after an afebrile interval of as long as 2 weeks, develop severe central nervous system manifestations.
The virus is transmitted by the bite of an ixodid tick, with cases occurring during the dry seasons of summer and autumn. The transmission cycle is believed by some to involve wild rodents and insectivores. Humans and monkeys are accidental hosts—the disease is often called "monkey fever."
A closely related virus has recently been identified as a cause of human disease in Saudi Arabia, having first been recovered from the blood of 6 male butchers.3
The largest city in Karanataka state is Bangalore, the "Silicon Valley" of India, and many individuals in the computer industry travel frequently between the United States and Bangalore, which is southeast of the area affected by Kyasanur Forest disease. Individuals returning from Bangalore with a febrile illness should, among other things, be asked about any side trips during their visit.
References
1. Richman DD, Whitley RJ, Hayden FG, eds. Clinical Virology. 2nd ed. Washington, DC: American Society for Microbiology; 2002.
2. Pavri K. Clinical, clinicopathologic, and hematologic features of Kyasanur Forest disease. Rev Infect Dis. 1989;11(Suppl 4):S854-S859.
3. Zaki AM. Isolation of a flavivirus related to the tick-borne encephalitis complex from human cases in Saudi Arabia. Trans R Soc Trop Med Hyg. 1997;91:179-181.
Dr. Derenski is Clinical Professor of Medicine, Stanford; Associate Chief of Infectious Diseases, Santa Clara Valley Medical Center.
Kyasanur Forest disease, also known as monkey fever, is a cause of hemorrhagic fever with late CNS manifestations in a geographically delimited area of India.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
- Award-winning Medical Content
- Latest Advances & Development in Medicine
- Unbiased Content