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|Venezuelan hemorrhagic fever|
Venezuelan hemorrhagic fever ( VHF ) is a zoonotic human illness first identified in 1989. The disease is most prevalent in several rural areas of central Venezuela and is caused by Guanarito mammarenavirus ( GTOV ) which belongs to the Arenaviridae family. The short-tailed cane mouse ( Zygodontomys brevicauda ) is the main host for GTOV which is spread mostly by inhalation of aerosolized droplets of saliva, respiratory secretions, urine, or blood from infected rodents. Person-to-person spread is possible, but uncommon.ContentsPresentation[ edit ]
VHF has many similarities to Lassa fever and to the arenavirus hemorrhagic fevers that occur in Argentina and Bolivia. It causes fever and malaise followed by hemorrhagic manifestations and convulsions. Some presentations of the virus are also characterized by vascular damage, bleeding diathesis, fever, and multiple organ involvement. Clinical diagnosis of VHF has proven to be difficult based on the nonspecific symptoms . The disease is fatal in 30% of cases and is endemic to Portuguesa state and Barinas state in Venezuela .
Treatment and prevention for the VHF virus are limited and there are currently no licensed vaccines available that can act to prevent the disease. However, once infected, ribavirin , an anti-viral drug given intravenously, is one way to treat VHF.Virus[ edit ]
Arenaviruses are enveloped, single-stranded, bisegmented RNA viruses with antisense genomes. Based on their antigenic properties, arenaviruses have been classified into two major groups: the Old World arenaviruses, and the New World arenaviruses. Old World arenaviruses include lymphocytic choriomeningitis virus and Lassa virus . New world arena viruses are further broken down into three clades, A, B, and C. The Guanarito arena virus belongs to clade B and is the cause of VHF. On the biosafety level scale of one to four, with four causing the most risk, the viruses causing hemorrhagic fevers have been assigned a four by the CDC.Host[ edit ]
The short-tailed cane mouse, the main host of GTOV, is native to western Venezuela and resides in large numbers in tall grass, cultivated agricultural fields, human homes, and outbuildings. It is speculated that demographic and ecological changes in the rural areas increased the frequency of contact between humans and infected rodents such that VHF emerged.History[ edit ]
From September 1989 through December 2006, the State of Portuguesa recorded 618 cases of VHF. Nearly all of the cases were individuals who worked or lived in Guanarito during the time they became infected. The case fatality rate was 23.1%.
Because the virus is contracted by aerosol dissemination, concern arose shortly after the first cases emerged in 1989 due to fear of biological warfare . Potential biological terrorism agents were identified and categorized in 1999 by the Centers for Disease Control and Prevention (CDC) as part of the Congressional initiative to further response capabilities to biological weapons. Arenaviruses causing hemorrhagic fevers , along with a genus of virus called filoviruses, were categorized in Category A; these are pathogens with the highest potential impact on public health safety.
A notable event in the timeline of this virus' scientific knowledge was the unexplained disappearance of a vial of the virus at the University of Texas Medical Branch Galveston National Laboratory, announced 2013 March 24.References[ edit ] "ICTV Taxonomy history: Guanarito mammarenavirus " (html). International Committee on Taxonomy of Viruses (ICTV). Retrieved 4 March 2019. Salas R, de Manzione N, Tesh RB, et al. (October 1991). "Venezuelan haemorrhagic fever". Lancet. 338 (8774): 1033–6. doi : 10.1016/0140-6736(91)91899-6 . PMID 1681354 . S2CID 22660700 .Milazzo ML, Cajimat MN, Duno G, et al. (December 2011). "Transmission of Guanarito and Pirital viruses among wild rodents, Venezuela" . Emerging Infect. Dis. 17 (12): 2209–15. doi : 10.3201/eid1712.110393 . PMC 3311192 . PMID 22172205 .^ Radoshitzky SR, Kuhn JH, Spiropoulou CF, et al. (February 2008). "Receptor determinants of zoonotic transmission of New World hemorrhagic fever arenaviruses" . Proc. Natl. Acad. Sci. U.S.A. 105 (7): 2664–9. doi : 10.1073/pnas.0709254105 . PMC 2268193 . PMID 18268337 .de Manzione N, Salas RA, Paredes H, et al. (February 1998). "Venezuelan hemorrhagic fever: clinical and epidemiological studies of 165 cases" . Clin. Infect. Dis. 26 (2): 308–13. doi : 10.1086/516299 . PMID 9502447 .^ Hruby, D.E., Bolken, T.C., & Dai, D. (2011). U.S. Patent No. 7,872,037 . Corvallis, OR: Siga Technologies, Inc.(May 19, 2011).Special Pathogens Branch. Centers for Disease Control and Prevention. https://www.cdc.gov/ncidod/dvrd/spb/mnpages/disinfo.htm ^ Fulhorst CF, Cajimat MN, Milazzo ML, et al. (2008). "Genetic diversity between and within the arenavirus species indigenous to western Venezuela" . Virology. 378 (2): 205–13. doi : 10.1016/j.virol.2008.05.014 . PMC 2583173 . PMID 18586298 . "Virus vial missing from Galveston lab" . ETX News. 24 March 2013. Archived from the original on 30 March 2013.External links[ edit ]