Abstract
BackgroundThe reintroduction of sylvatic yellow fever in the state of São Paulo after about six decades was confirmed in the Northwestern region in 2000, where in 2008 there also occurred an important epizootic. The purpose of this study was to investigate the feeding habits of culicids potentially involved in the sylvatic transmission of the virus in this region.MethodsSpecimens were collected in 24 forested localities at ground level with hand nets and mouth aspirators. Collections were made quarterly between October 2006 and July 2008 during daylight hours. Blood-meal identification was carried out in mosquitoes of the tribes Aedini, Mansoniini and Sabethini. The biotin/avidin sandwich ELISA was employed to determine six source types: bird, bovine, equine, rat, human and monkey.ResultsA total of 24,879 females of the three tribes were obtained, 245 (0.98%) of which were engorged. The presence of three different blood sources per engorged female was the predominant situation, and included 35.10% of the total of samples processed. Samples with two or four different sources were represented by 25.31% and 25.71%, of the specimens, respectively, while just 9.39% had only one type and 1.22%, five different sources. Aedes scapularis, Ae. serratus (Group), Psorophora albigenu and Ps. ferox were the most abundant species and accounted for about 95% of the engorged specimens. Of the principal vector species, Haemagogus janthinomys/capricornii was found with bird, bovine and primate blood. These sources were predominant and alternated top ranking as the most frequent source according to the mosquito species and collection site. In general, primate blood was the most prevalent source.ConclusionsThe human population of the region visits this ecotone frequently, which indicates the need for the periodical assessment of vaccination coverage against yellow fever. The frequency of non-human primate blood source in mosquito species that show minor vector importance in yellow fever virus transmission deserves attention. The eclectic feeding habits and some aspects of the interactions between potential vectors and reservoirs of yellow fever may be associated with the habitat fragmentation characteristic of the region. We recommend that further studies on the capacity and vector competence be performed on secondary vectors in extra-Amazonian region.Electronic supplementary materialThe online version of this article (doi:10.1186/s40409-015-0005-z) contains supplementary material, which is available to authorized users.
Highlights
The reintroduction of sylvatic yellow fever in the state of São Paulo after about six decades was confirmed in the Northwestern region in 2000, where in 2008 there occurred an important epizootic
The last 20 years have been characterized by the expansion of sylvatic transmission of yellow fever beyond the Amazonian biome in Brazil [1]
The participation of other mammals in the maintenance of the virus and the influence of the double vector-reservoir role of the mosquitoes in the disease cycle are discussed [1,8,9]. It was recently suggested a potential mediation of human migrations in virus dispersion based on genetic divergence in Brazilian strains [10]
Summary
The reintroduction of sylvatic yellow fever in the state of São Paulo after about six decades was confirmed in the Northwestern region in 2000, where in 2008 there occurred an important epizootic. The last 20 years have been characterized by the expansion of sylvatic transmission of yellow fever beyond the Amazonian biome in Brazil [1] This situation represents a serious challenge for public health services, especially in relation to the improvement of surveillance systems, the defining of strategies for the immunization of the susceptible population and the adoption of preventive measures to avoid urban transmission [2,3,4,5,6]. The participation of other mammals in the maintenance of the virus and the influence of the double vector-reservoir role of the mosquitoes in the disease cycle are discussed [1,8,9] It was recently suggested a potential mediation of human migrations in virus dispersion based on genetic divergence in Brazilian strains [10]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call