Yellow Fever transmission in Brazil

Abstract

Yellow fever (YF) is an arboviral disease caused by a virus from Flaviviridae family and genus Flavivirus endemic in tropical regions of Africa and South America. Transmission occurs after infected mosquito bite, genera Aedes and Haemogogus. Urban YF was eradicated in Brazil in 1942, since than sporadic wild transmission has been maintained in country endemic area. From 1989 to 2008, 546 human confirmed cases YF were reported including 241 deaths (case fatality rate 44, 1%) in Brazil. During this period north and midwestern region were responsible for the highest number of cases registering human cases almost every year. Beginning in 1999, YF virus underwent a geographic expansion into southeast, south and midwestern region - Federal District, Goias, Sao Paulo, Minas Gerais, Parana and Rio Grande do Sul states – related to outbreaks in areas that were silent for several decades and outside Amazon area. This study describes the re-emergence of YF virus in enzootic cycles involving mosquitoes, primates and humans cases in midwestern, southeast and south region during 2008 and 2009. During this period and explosive recording of monkey's death was registry by health authorities with laboratory confirmed epizootics. Human cases were associated with leisure and work activities in rural areas and occurred among unvaccinated person. Brazilian Ministry of Health considered it as a public health event of national concern according to the International Health Regulations (2005). Epidemiological control measures were adopted including entomologic control and assessments, monkey deaths surveillance investigation and mass vaccination campaigns were implemented. YF vaccine-associated viscerotropic and neurotropic disease were reported. Those activities were important to establish an effective intervention to control and prevent future outbreaks. Public health authority's interest has been awakened by reporting early identification of YF virus circulation to understand the potential geographic virus expansion and reemergence. Abstracts for SupplementInternational Journal of Infectious DiseasesVol. 14Preview Full-Text PDF Open Archive