Rift Valley fever 26378 210435895 2008-05-05T22:41:33Z Puceron 5792803 /* Animal vaccination */ {{DiseaseDisorder infobox | Name = Rift Valley fever | Image = Rift Valley fever tissue.jpg | Caption = <center>[[Transmission electron microscopy|TEM]] [[micrograph]] of tissue infected with Rift Valley fever virus</center> | ICD10 = {{ICD10|A|92|4|a|90}} | ICD9 = {{ICD9|066.3}} | }} {{Taxobox <!-- Color parameter is not needed -- automatically assigned --> | name = ''Rift Valley Fever virus'' | virus_group = v | familia = ''[[Bunyaviridae]]'' | genus = ''[[Phlebovirus]]'' | species = ''Rift Valley Fever virus'' }} '''Rift Valley Fever (RVF)''' is a viral [[zoonosis]] (affects primarily domestic [[livestock]], but can be passed to humans) causing [[fever]]. It is spread by the bite of infected [[mosquito]]es. The disease is caused by the RVF [[virus (biology)|virus]], a member of the genus ''Phlebovirus'' (family ''Bunyaviridae''). The disease was first reported among livestock in [[Kenya]] around [[1915]], but the virus was not isolated until [[1931]]. RVF outbreaks occur across sub-Saharan [[Africa]], with outbreaks occurring elsewhere infrequently (but sometimes severely - in [[Egypt]] in [[1977]]-78, several million people were infected and thousands died during a violent epidemic. In [[Kenya]] in 1998, the virus claimed the lives of over 400 Kenyans. In September [[2000]] an outbreak was confirmed in [[Saudi Arabia]] and [[Yemen]]). In humans the virus can cause several different syndromes. Usually sufferers have either no symptoms or only a mild illness with fever, [[headache]], [[myalgia]] and [[liver]] abnormalities. In a small percentage of cases (< 2%) the illness can progress to [[hemorrhagic fever]] syndrome, [[meningoencephalitis]] (inflammation of the brain), or affecting the eye. Patients who become ill usually experience fever, generalized weakness, back pain, dizziness, and weight loss at the onset of the illness. Typically, patients recover within 2-7 days after onset. [[Image:Rift valley fever distribution.jpg|right|thumb|280px|Distribution of Rift Valley Fever in Africa. Blue, countries with endemic disease and substantial outbreaks of RVF; green, countries known to have some cases, periodic isolation of virus, or serologic evidence of RVF.]] Approximately 1% of human sufferers die of the disease. Amongst livestock the fatality level is significantly higher. In pregnant livestock infected with RVF there is the [[abortion]] of virtually 100% of fetuses. An epizootic (animal disease epidemic) of RVF is usually first indicated by a wave of unexplained abortions. ==Animal vaccination== Several animal [[vaccines]] have been made to protect against RVF infection. The first one to be developed was a [[Vaccine|live vaccine]]. When administered to mice, the results were promising, this vaccine provided [[immunity (medical)|immunity]] for 3 years. However a problem was encountered: administration to pregnant ewes on many occasions led to [[abortion]]. From there on in, [[attenuated]] vaccines have been developed. Although they are protective, and do not cause adverse effects, this was only achieved after multiple [[inoculation]]s. The fact that multiple doses were required could prove problematic especially in areas where RVF is [[endemic (epidemiology)|endemic]]. ==2006/07 outbreak in Kenya & Somalia== In November 2006, a Rift Valley fever outbreak occurred in [[Kenya]]. The victims are from the [[North Eastern Province (Kenya)|North Eastern Province]] and [[Coast Province]] of Kenya, which have received heavy rain in recent months, causing floods and creating breeding grounds for [[mosquitoe]]s which spread the virus of the fever from infected livestock to humans. As of [[7 January]] [[2007]], about 75 people have died and another 183 infected. <ref>{{cite news | title = At least 75 people die of Rift Valley Fever in Kenya | url = http://www.iht.com/articles/ap/2007/01/07/africa/AF-GEN-Kenya-Rift-Valley-Fever.php | date = 7 Jaunary 2007 | publisher = International Herald Tribune }} </ref> The outbreak has forced the closure of livestock markets in the North Eastern Province, affecting the economy of the region.<ref>{{cite news | title = Kenya: Schools Disrupted As Deadly Fever Hits Incomes | publisher = [[IRIN]] | date = [[11 January]] [[2007]] | url = http://www.reliefweb.int/rw/RWB.NSF/db900SID/LZEG-6XCNZ7?OpenDocument}}</ref> The outbreak was subsequently reported to have moved into [[Maragua District|Maragua]] and [[Kirinyaga District|Kirinyaga]] districts of [[Central Province (Kenya)|Central Province]] of Kenya.<ref>{{cite news | title = Nairobi at risk of RVF infection | publisher = [[The Standard (Kenya)]] | date = [[22 January]] [[2007]] | url = http://www.eastandard.net/hm_news/news.php?articleid=1143963928}}</ref> On [[20 January]] [[2007]] the outbreak was reported to have crossed into [[Somalia]] from Kenya and killed 14 people in the [[Jubbada Hoose|Lower Jubba]] region.<ref>{{cite news | title = 14 die after Rift Valley Fever breaks out in southern Somalia | publisher = Shabelle Media Network, Somalia | date = [[20 January]] [[2007]] | url = http://www.shabelle.net/news/ne2114.htm}}</ref> As of 23rd January 2007 cases had started to crop at the Kenyan capital [[Nairobi]]. An estimated large number of businesses were supposedly suffering large losses as customers were shunning the common meat joints for the popular [[Nyama Choma]] (Roast meat), as it was believed to be spreading the fever. In December of 2006 and again in January of 2007, Taiwan International Health Action (TaiwanIHA) began operating missions in Kenya [http://www.mofa.gov.tw/webapp/content.asp?cuItem=25148&mp=6] consisting of medical experts assisting laboratory training and health facility personnel, and included donations of supplies such as mosquito sprays. The United States Centers for Disease Control has also set up an assistance mission and laboratory in Kenya. By the end of January, 2007, some 148 people have died since the outbreak began in December. As at 14 March 2007, the Kenyan government declared RVF as having diminished drastically after spending an estimated 2.5 Million in Vaccine and deployment costs, It also lifted the ban on cattle movement in the affected areas. As of 2 November 2007, 125 cases including 60 deaths have been reported from more than 10 localities of White Nile, Sinnar, and Gezira states in Sudan. Young adult males are predominantly affected. More than 25 human samples have been found positive for RVF by PCR or ELISA.<ref>{{cite news | title = Deadly fever spreads Kenya Panic | publisher = BBC| date = [[26 January]] [[2007]] | url = http://news.bbc.co.uk/2/hi/africa/6301417.stm}}</ref> ==References== {{reflist}} ==External links== *[http://www.cdc.gov/ncidod/dvrd/spb/mnpages/dispages/rvf.htm Official CDC RVF Information Page] *[http://www.who.int/mediacentre/factsheets/fs207/en/ WHO Rift Valley fever] {{Viral diseases}} [[Category:Viral diseases]] [[Category:Bunyaviruses]] [[Category:Zoonoses]] [[Category:Insect-borne diseases]] [[ar:حمى الوادي المتصدع]] [[de:Rifttalfieber]] [[fa:تب دره ریفت]] [[fr:Fièvre de la vallée du Rift]] [[it:Febbre della Rift Valley]] [[nl:Riftdalkoorts]] [[ja:リフトバレー熱]] [[wa:Five del Vå do Rift]] [[zh:裂谷熱]]