Entomological investigation of a sylvatic yellow fever area in São Paulo State, Brazil

Abstract

Following reports of two autochthonous cases of sylvatic yellow fever in the State of São Paulo, Brazil, in 2000, entomological surveys were conducted with the objective of verifying the occurrence of vector species in forest environments close to or associated with riparian areas located in the western and northwestern regions of the State. Culicidae were captured in 39 sites distributed in four regions. Haemagogus leucocelaenus and Aedes albopictus were the most abundant species and were captured in all the regions studied. H. leucocelaenus was the most abundant species in the municipalities of Santa Albertina and Ouroeste, where the two cases of sylvatic yellow fever had been reported. Mosquitoes from the janthinomys/capricornii group were only found at eight sites in the São José do Rio Preto region, while Sabethes chloropterus was found at one site in Ribeirão Preto. H. leucocelaenus showed its capacity to adapt to a secondary and degraded environment. Our results indicate a wide receptive area for yellow fever transmission in the State of São Paulo, with particular emphasis on the possibility of H. leucocelaenus being involved in the maintenance of this sylvatic focus of the disease.

Isolation of Yellow Fever Virus from Mosquitoes in Misiones Province, Argentina

“…All mosquitoes captured were studied for flavivirus detection using reverse-transcription PCR; however, Sabethes and Haemagogus genus mosquitoes were selectively tested for YFV because these genera have been associated with transmission of YFV in sylvatic areas in South America (Monath 1999;Vasconcelos 2003;Camargo-Neves et al 2005). In 2001 and 2008 strains of YFV were isolated from Haemagogus leucocelaenus, and from Aedes serratus in Rio Grande do Sul State, Brazil Cardoso et al 2010).…”

“…The enzootic transmission cycle involves two components: the mosquitoes and the nonhuman primates. In Africa the vector involved in this enzootic cycle is a mosquito from the genus Aedes, whereas in South America the vectors associated with the transmission cycle are mosquitoes from the genera Haemagogus and Sabethes (Monath 1999;Vasconcelos 2003;Camargo-Neves et al 2005).…”

Detection of a new yellow fever virus lineage within the South American genotype I in Brazil

“…The introduction of new virus strains seems to be a continuous, overlapping process that have been causing low-level virus transmission, and a progressive genetic divergence. Moreover, the intensive human migration and heavy deforestation caused by the use of land may drive changes in mosquito species composition, alteration in mosquito behavior, and an increase in non-human primate dispersion [Vasconcelos et al, 2001a;Vasconcelos, 2002;Camargo-Neves et al, 2005]. Fig.…”

Circulation of antibodies against yellow fever virus in a simian population in the area of Porto Primavera Hydroelectric Plant, São Paulo, Brazil

“…Another entomological study aimed to describing vector species within the western and northwestern region of the state of São Paulo 4 . Collections were carried out in 39 localities in four different areas.…”