Brazil, Angola, Democratic Republic of Congo and Nigeria recorded significant yellow fever (YF) outbreaks during 2016, 2017 and 2018, attributing to several deaths. YF is caused by a virus (Flavivirus) which is transmitted to humans through infected mosquito bites. The sylvatic YF reemergence, despite the availability of an effective vaccine, requires more research to identify the geographical distribution and eco-epidemiological aspects of the sylvatic mosquito species consociated with the yellow fever disease sustention and consequent dissemination. According to the World Health Organization, these recent outbreaks are forewarnings of worse to come, if no action is taken. Understanding mosquitoes’ biology facilitates the control and prevention of YF, and is vital in situations where the vaccination coverage is low or the vaccine is not readily available. The aim of this study is to review and describe the biological and ecological aspects of the mosquito genera Haemagogus and Sabethes, being the two most prevalent vectors and repositories of this virus type, and their role in the preservation and transmission of sylvatic YF in Brazil, imperatively noting the probability of transvaginal and transestadial transmission from female mosquitoes to their eggs and resultant larvae, which further perpetuates the disease. This transmittal adaptation may explain the isolated outbreaks in previously uninfected areas. Another contributing factor to recent outbreaks is the change in human lifestyles, ingenuously invading forest areas triggering inadvertent infections. This circumstance would be efficiently controlled if population growth did not invade these vector-infested & virus-infected forest ecosystems. Moreover, the degradation of these sylvatic mosquito habitats and their propensity to explore instigates their permeation throughout urban areas, enhancing mosquito-human interactions. The results contributed to the formation of an environmental surveillance, incorporating the analysis of the influence of geographical locations of the mosquitoes within YF outbreak regions, capacitating the creation of prevention alternatives for new cases.
Buy this Article