Mr. Benson
Bio-116-001
21 October 2014
Yellow fever: An epidemiological and historical review
Introduction
Few diseases have attracted more attention from medical historians than yellow fever (YF). It was one of the most feared of epidemic diseases in the world from the 15th to 19th centuries, when large scale outbreaks in port cities of North and South America, Africa, and Europe caused devastating mortality and helped to shape the expansion of settlements and colonial powers (1). Yellow fever is a serious viral infection that 's usually carried to human by female mosquitoes. It’s scientific name Aedes aegypti mosquito (Fig.1).
Fig.1: Female of Aedes aegypti mosquito.
The disease is caused by the yellow fever virus and is spread by the bite of the female mosquito (Fig. 2) (2). It only infects humans, other primates, and several species of mosquitoes. In cities, it is primarily spread by mosquitoes of the Aedes aegypti species. The virus is an RNA virus of the genus Flavivirus (Fig. 3)(3). The disease may be difficult to tell apart from other illnesses, especially in the early stages.[2] To confirm a suspected case, blood sample testing with polymerase chain reaction is required.(4)
Fig.2: Mosquitoes pass yellow fever virus to humans through a small amount of saliva when they bite.
Fig.3: A TEM micrograph of the yellow fever virus (234,000X magnification)
Vectors
The yellow fever mosquito: Aedes aegypti Aedes aegypti is the quintessential urban vector of yellow fever and dengue. It is a remarkable specie because the ‘domesticated’ form is rarely found more than 100 m from human habitation and feeds almost exclusively on human blood. Nevertheless, like its forest ancestor, it remains day-active with a preference for heavy shade (5). It freely enters homes and other buildings and spends much of its time hidden in dark places, often among clothing, a stable microclimate with few predators. Its human host is abundant and lives under
Cited: Lindenbach, B. D., et al. 2007. "Flaviviridae: The Viruses and Their Replication". In Knipe, D. M. and P. M. Howley. (eds.). Fields Virology (5th ed.). Philadelphia, PA: Lippincott Williams & Wilkins. p. 1101. ISBN 0-7817606-0-7. Tolle M.A . 2009. "Mosquito-borne diseases". Curr Probl Pediatr Adolesc Health Care 39 (4): 97–140. Arnebeck B World Health Organization. 2011. Vaccine-preventable diseases: monitoring system 2008. Global summary. Yellow Fever [Accessed 31 August 2011]. Medical Review: January 24, 2013 Coalbunkers R Medical Review: January 22, 2012 World Health Organization McFarland J, Baddour LM, Nelson JE et al., 1997. Imported yellow fever in a United States citizen. Clin Infect Dis. 25:1143-7. Reiter P. 2009. Yellow fever and dengue: a threat to Europe?. Euro Surveill. 2010;15(10):pii=19509. Review articles Date of submission: 06 May 2009 .