ABSTRACT
A febre amarela (FA) se mantém endêmica ou enzoótica na África e Américas do Sul e Central, causada por um arbovírus mantido em ciclos silvestres em que primatas não humanos (PNH) são os principais hospedeiros amplificadores e mosquitos das tribos Aedini e Sabethini são os transmissores. O homem participa deste ciclo como um hospedeiro acidental ao contatar áreas de mata com animais infectados e mosquitos transmissores. Durante o surto de FA ocorrido no estado de São Paulo entre os anos de 2016 e 2018 foram registradas mortes de PNH no Parque Estadual da Cantareira (PEC) e infecções humanas foram relatadas nas proximidades, sinalizando para o risco de transmissão do vírus amarílico neste remanescente de mata situado na região metropolitana de São Paulo. Foi objetivo de estudo investigar os culicídeos potencialmente associados à transmissão de febre amarela silvestre (CPAFAS) no PEC e elaborar um manual de coleta diurna de Culicidae em ambiente florestal urbano para auxiliar o trabalho de vigilância entomológica realizado no município de São Paulo (MSP). As coletas foram quinzenais no Núcleo Engordador, nas trilhas do Macuco e Mountain Bike, entre 10 e 14 horas, de março de 2019 a fevereiro de 2020. Para as coletas foram utilizados puçá entomológico para captura de indivíduos adultos e instalação de armadilhas larvitrampas (bambu e PET) no solo e na copa das árvores para coleta de imaturos. Para os adultos de CPAFAS foram estimadas a riqueza e abundância; comparou-se a diversidade da fauna coletada nas duas trilhas utilizando-se o teste de Mann-Whitney; correlacionou-se o total de indivíduos coletados com dados climáticos (temperatura, pluviosidade e umidade relativa do ar por meio do coeficiente de correlação de Sperman. Para os imaturos comparou-se a abundância do total de CPAFAS e Hg. leucocelaenus coletados nas larvitrampas nas duas alturas instaladas utilizando a análise de Wilcoxon. Foram coletados um total de 248 espécimes de adultos e 136 de imaturos de CPAFAS pertencentes a 13 espécies distribuídas nos gêneros Aedes, Haemagogus, Psorophora e Sabethes. Os resultados mostraram que não houve diferença estatisticamente significativa de diversidade entre as trilhas, indicando terem as mesmas características relativas à fauna de CPAFAS. Ocorreu correlação positiva entre o total de CPAFAS e as variáveis climáticas de temperatura e pluviosidade dos 30 dias que antecederam à coleta. Ao se comparar a abundância dos CPAFAS nas larvitrampas, observou-se a preferência por armadilhas de bambu. Em relação à altura de colocação das armadilhas a maior frequência ocorreu no bambu copa, quando se considerou o total de CPAFAS. Para Hg. leucocelaenus, não foi constatada diferença estatisticamente significativa no bambu copa ou solo indicando que a espécie explora diferentes níveis de habitats florestais. Estes resultados sinalizam que o PEC é uma área que merece atenção para a vigilância de vetores da FA, recomendando a continuação do monitoramento diurno no parque e em outras áreas vulneráveis à transmissão da FA no MSP e propondo à coordenação do Laboratório de Identificação e Pesquisa em Fauna Sinantrópica do MSP um manual de coleta diurna de culicídeos.
Yellow fever (YF) remains endemic or enzootic in Africa and South and Central America, is caused by an arbovirus maintained in wild cycles in which non-human primates (NHP) are the main hosts and mosquitoes from the Aedini and Sabethini tribes are the vectors. Humans participate of this cycle as accidental hosts when contacting forest areas with infected animals and mosquito vectors. During the YF outbreak that occurred in the state of São Paulo between 2016 and 2018, were recorded deaths of NHP in the Cantareira State Park (CSP) and human infections nearby, signaling the risk of the YF virus transmission in this area remaining of forest located in the metropolitan region of São Paulo. The aims of this study were to investigate the specimens of Culicidae potentially associated with the wild yellow fever transmission dynamics (CPAFAS) in the CSP and to develop a manual for daytime collection of Culicidae in an urban forest environment to assist the entomological surveillance activities carried out in the municipality of São Paulo (MSP). Collections performed fortnightly at Núcleo Engordador, on the Macuco and Mountain Bike trails, between 10 a.m. and 2 p.m., and from March 2019 to February 2020. To collections were used aerial insect nets to capture adult individuals and larvitraps traps (bamboo and PET) on soil and treetop for collecting immature. For CPAFAS adults, species richness and abundance were estimated; the diversity of fauna collected on the two trails was compared using the Mann-Whitney test; the total number of individuals collected was correlated with climatic data (temperature, rainfall and relative humidity) using Spearman's correlation coefficient. For immatures, the abundance of total CPAFAS and Hg. leucocelaenus collected from larvitraps in the two installed level were compared using Wilcoxon analysis. A total of 248 adults and 136 immature specimens of CPAFAS belonging to 13 species distributed between the genera Aedes, Haemagogus, Psorophora and Sabethes were collected. The results showed that there was no statistically significant difference in diversity between trails, indicating that they have the same characteristics regarding the CPAFAS fauna. There was a positive correlation between the total of CPAFAS and the climatic variables of temperature and rainfall in the 30 days prior to collection. When comparing the abundance of CPAFAS in larvitraps, the preference for bamboo traps was observed. Regarding the level of traps placement, the highest frequency occurred in bamboo traps placed at treetop level, when considering the total of CPAFAS. For Hg. leucocelaenus, no statistically significant difference was found between bamboo traps placed at treetop or soil level, indicating that the species explores different levels of forest habitats. These results indicate that the CSP is an area that deserves attention for YF vector surveillance. The continuation of daytime monitoring in the park and other areas vulnerable to YF transmission in the MSP is recommended and a manual for daytime collection of Culicidae is proposed to the coordination of the Identification and Research Laboratory in Synanthropic Fauna of the MSP.
Subject(s)
Yellow Fever , Entomology , CulicidaeABSTRACT
The dengue viruses are widespread in Brazil and are a major public health concern. Other flaviviruses also cause diseases in humans, although on a smaller scale. The city of São Paulo is in a highly urbanized area with few green spaces apart from its parks, which are used for recreation and where potential vertebrate hosts and mosquito vectors of pathogenic Flavivirus species can be found. Although this scenario can contribute to the transmission of Flavivirus to humans, little is known about the circulation of members of this genus in these areas. In light of this, the present study sought to identify Flavivirus infection in mosquitoes (Diptera: Culicidae) collected in parks in the city of São Paulo. Seven parks in different sectors of the city were selected. Monthly mosquito collections were carried out in each park from March 2011 to February 2012 using aspiration and traps (Shannon and CD C-CO2). Nucleic acids were extracted from the mosquitoes collected and used for reverse-transcriptase and real-time polymerase chain reactions with genus-specific primers targeting a 200-nucleotide region in the Flavivirus NS5 gene. Positive samples were sequenced, and phylogenetic analyses were performed. Culex and Aedes were the most frequent genera of Culicidae collected. Culex flavivirus (CxFV)-related and Aedes flavivirus (AEFV)- related nucleotide sequences were detected in 17 pools of Culex and two pools of Aedes mosquitoes, respectively, among the 818 pools of non-engorged females analyzed. To the best of our knowledge, this is the first report of CxFV and AEFV in the city of São Paulo and Latin America, respectively. Both viruses are insect- specific flaviviruses, a group known to replicate only in mosquito cells and induce a cytopathic effect in some situations. Hence, our data suggests that CxFV and AEFV are present in Culex and Aedes mosquitoes, respectively, in parks in the city of São Paulo. Even though Flavivirus species of medical importance were not detected, surveillance is recommended in the study areas because of the presence of vertebrates and mosquitoes that could act as amplifying hosts and vectors of flaviviruses, providing the required conditions for circulation of these viruses.
Subject(s)
Aedes/virology , Culex/virology , Flavivirus/genetics , Flavivirus/isolation & purification , Animals , Base Sequence , Brazil , Cities , Female , Humans , Parks, Recreational , PhylogenyABSTRACT
A mosquito faunal survey was conducted from October 2010 to February 2011 in the municipal parks of São Paulo City, Brazil. A total of 7,015 specimens of 53 taxonomic categories grouped into 12 genera (Aedes, Anopheles, Coquilletidia, Culex, Limatus, Lutzia, Mansonia, Psorophora, Toxorhynchites, Trichoprosopon, Uranotaenia, and Wyeomyia) were collected. The largest and most peripheral parks showed greater species richness compared to smaller and more centralized parks.
