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| | '''For patient information click [[{{PAGENAME}} (patient information)|here]]''' |
| {{DiseaseDisorder infobox | | | {{DiseaseDisorder infobox | |
| Name = Kyasanur forest disease | | | Name = Kyasanur forest disease | |
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| ==Overview== | | ==[[Kyasanur forest disease overview|Overview]]== |
| '''Kyasanur forest disease''' is a [[tick-borne disease|tick-borne]] [[viral hemorrhagic fever]] endemic to [[South Asia]]. The disease is caused by a virus belonging to the family [[flaviviridae]].
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| ==Historical Perspective== | | ==[[Kyasanur forest disease historical perspective|Historical Perspective]]== |
| The disease was first reported from Kyasanur Forest of [[Karnataka]] in [[India]] in March 1957. The disease first manifested as an [[epizootic]] outbreak among monkeys killing several of them in the year 1957. Hence the disease is also locally known as '''Monkey Disease''' or '''Monkey Fever'''.<ref name=ethno>{{cite journal|title=Kyasanur Forest Disease: An Ethnography of a Disease of Development| author=Nichter, Mark|journal=Medical Anthropology Quarterly, New Series| volume=1| issue=4| year=1987|pages=406–423}}</ref> The similarity with [[Spring-summer encephalitis|Russian Spring-summer encephalitis]] was noted and the possibility of migratory birds carrying the disease was raised.<ref>{{cite journal|doi=10.2105/AJPH.49.7.869|author=Work, Telford H.|last2=Roderiguez|first2=FR|last3=Bhatt|first3=PN| title=Virological Epidemiology of the 1958 Epidemic of Kyasanur Forest Disease|year=1959| pages=869–874 |volume=49| issue=7| journal=American Journal of Public Health|pmid=13661478|pmc=1372906}}</ref> Studies began to look for the possible species that acted as reservoirs for the virus and the agents responsible for transmission. Subsequent studies failed to find any involvement of migratory birds although the possibility of their role in initial establishment was not ruled out. The virus was found to be quite distinctive and not closely related to the Russian virus strains. Antigenic relatedness is however close to many other strains including the Omsk hemorrhagic fever (OHF) and birds from Siberia have been found to show an antigenic response to KFD virus. Sequence based studies however note the distinctivenss of OHF.<ref>{{cite journal|doi=10.1016/S0042-6822(03)00246-0|journal=Virology|year=2003 | volume=313|issue=1|pages=81–90| title=Analysis of the complete genome of the tick-borne flavivirus Omsk hemorrhagic fever virus| author=Lin D, Li L, Dick D, Shope RE, Feldmann H, Barrett AD, Holbrook MR|pmid=12951023}}</ref> Early studies in India were conducted in collaboration with the US Army Medical Research Unit and this led to controversy and conspiracy theories.<ref>{{cite journal|journal=Bulletin World Health Organ.|year=1963|volume=28| issue=2|pages=235–262|title=Ticks (Ixodidae) on birds migrating from Europe and Asia to Africa, 1959-61|author=Harry Hoogstraal, Makram N. Kaiser, Melvin A. Traylor, Ezzat Guindy, and Sobhy Gaber|pmc=2554471|pmid=13961632}}</ref><ref>{{cite journal|author=Lewis, Michael |year=2002| title= Scientists or Spies? Ecology in a Climate of Cold War Suspicion| journal= Economic and Political Weekly|volume= 37|issue= 24|pages=2324–2332}}</ref>
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| Subsequent studies based on sequencing found that the [[Alkhurma virus]], found in [[Saudi Arabia]] is closely related.<ref>{{cite journal|doi=10.1006/bbrc.2001.5610|author=Charrel RN, Zaki AM, Attoui H, Fakeeh M, Billoir F, Yousef AI, de Chesse R, De Micco P, Gould EA, de Lamballerie X.|year=2001| title=Complete coding sequence of the Alkhurma virus, a tick-borne flavivirus causing severe hemorrhagic fever in humans in Saudi Arabia|journal=Biochem. Biophys Res. Commun. |volume=287|issue=2|pages=455–61|pmid=11554750}}</ref> In 1989 a patient in Nanjianin, China was found with fever symptoms and in 2009 its viral gene sequence was found to exactly match with that of the KFD reference virus of 1957. This has however been questioned since the Indian virus shows variations in sequence over time and the exact match with the virus sequence of 1957 and the Chinese virus of 1989 is not expected. This study also found using immune response tests that birds and humans in the region appeared to have been exposed to the virus.<ref>{{cite journal|journal=Emerg. Infect. Dis. |year=2009 |volume=15| issue=2|pmid=19193286|title=Isolation of Kyasanur Forest Disease Virus from Febrile Patient, Yunnan, China|pmc=2657630| pages= 326–328| doi= 10.3201/eid1502.080979|author=Jinglin Wang, Hailin Zhang, Shihong Fu, Huanyu Wang, Daxin Ni, Roger Nasci, Qing Tang, and Guodong Liang}}</ref> Another study has suggested that the virus is recent in origin dating the nearest common ancestor of it and related viruses to around 1942, based on the estimated rate of sequence substitutions. The study also raises the possibility of bird involvement in long-distance transfer.<ref>{{cite journal|author= Rajeev Mehla, Sandeep R.P. Kumar, Pragya Yadav, Pradip V. Barde, Prasanna N. Yergolkar, Bobbie R. Erickson, Serena A. Carroll, Akhilesh C. Mishra, Stuart T. Nichol, and Devendra T. Mourya|title=Recent Ancestry of Kyasanur Forest Disease Virus|doi=10.3201/eid1509.080759|pmc= 2819879| journal=Emerging Infectious Diseases| volume=15|pmid= 19788811|year= 2009| issue=9| pages=1431–1437}}</ref> It appears that these viruses diverged 700 years ago.<ref name=Dodd2011>Dodd KA, Bird BH, Khristova ML, Albariño CG, Carroll SA, Comer JA, Erickson BR, Rollin PE, Nichol ST (2011) Ancient ancestry of KFDV and AHFV revealed by complete genome analyses of viruses isolated from ticks and mammalian hosts. PLoS Negl Trop Dis 5(10):e1352.</ref>
| | ==[[Kyasanur forest disease pathophysiology|Pathophysiology]]== |
| ==Pathophysiology==
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| ===Transmission=== | | ==[[Kyasanur forest disease causes|Causes]]== |
| The main hosts of Kyasanur forest disease virus (KFDV) are small rodents, but shrews, bats, and monkeys may also carry the virus. KFD is transmitted from the bite of an infected tick (Haemaphysalis spinigera is the major vector). Humans can get these diseases from a tick bite or by contact with an infected animal, such as sick or recently dead monkey.
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| | ==[[Kyasanur forest disease differential diagnosis|Differentiating Kyasanur forest disease from other Diseases]]== |
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| | ==[[Kyasanur forest disease epidemiology and demographics|Epidemiology and Demographics]]== |
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| | ==[[Kyasanur forest disease risk factors|Risk Factors]]== |
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| | ==[[Kyasanur forest disease natural history, complications and prognosis|Natural History, Complications and Prognosis]]== |
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| Larger animals such as goats, cows, and sheep may become infected with KFD, but they do not have a role in the transmission of the disease. Furthermore, there is no evidence of the disease being transmitted via the unpasteurized milk of any of these animals.
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| ==Epidemiology and Demographics==
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| There are approximately 400-500 cases of KFD per year with a [[case fatality]] rate of 3% to 5%.
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| ==Risk Factors==
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| People with recreational or occupational exposure to rural or outdoor settings (e.g., hunters, campers, forest workers, farmers) are potentially at risk for infection by contact with infected ticks.
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| ==Diagnosis== | | ==Diagnosis== |
| ===History and Symptoms===
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| After an [[incubation period]] of 3-8 days, the symptoms of KFD begin suddenly with [[fever]], [[headache]], severe muscle pain, [[cough]], [[dehydration]], [[gastrointestinal]] symptoms and [[bleeding]] problems. Patients may experience abnormally low [[blood pressure]]. After 1-2 weeks of symptoms, some patients recover without complication. However, in most patients, the illness is biphasic and the patient begins experiencing a second wave of symptoms at the beginning of the third week. These symptoms include fever and signs of [[encephalitis]] ([[inflammation]] of the brain).
| | [[Kyasanur forest disease history and symptoms|History and Symptoms]] | [[Kyasanur forest disease physical examination|Physical Examination]] | [[Kyasanur forest disease laboratory findings|Laboratory Findings]] | [[Kyasanur forest disease other diagnostic studies|Other Diagnostic Studies]] |
| ===Laboratory Findings===
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| The patients may have low [[platelet]], [[red blood cell]], and [[white blood cell]] counts. The diagnosis is made by virus isolation from blood or by [[serologic]] testing using enzyme-linked immunosorbent serologic assay ([[ELISA]]).
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| ==Treatment== | | ==Treatment== |
| There is no specific treatment for KFD, but supportive therapy is important. Supportive therapy includes the maintenance of hydration and the usual precautions for patients with bleeding disorders.
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| ==Prevention==
| | [[Kyasanur forest disease medical therapy|Medical Therapy]] | [[Kyasanur forest disease primary prevention|Primary Prevention]] | [[Kyasanur forest disease cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Kyasanur forest disease future or investigational therapies|Future or Investigational Therapies]] |
| [[Prophylaxis]] by vaccination, as well as preventive measures like protective clothing, tick control, and mosquito control are advised. An [[attenuated]] [[live vaccine]] is now available. Specific treatments are not available. | | |
| | ==Case Studies== |
| | [[Kyasanur forest disease case study one|Case #1]] |
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| ==Sources== | | ==Sources== |
| * CDC Kyasanur forest disease[http://www.cdc.gov/ncidod/dvrd/spb/mnpages/dispages/kyasanur.htm] | | * CDC Kyasanur forest disease[http://www.cdc.gov/ncidod/dvrd/spb/mnpages/dispages/kyasanur.htm] |