In Brazil, the mosquito Aedes (Stegomyia) aegypti is considered the main vector of the dengue, chikungunya, and Zika arbovirus transmission. Recent epidemiological studies in southern Brazil have shown an increase in the incidence of dengue, raising concerns over epidemiological control, monitoring, and surveys. Therefore, this study aimed at performing a historical spatiotemporal analysis of the Ae. aegypti house indices (HI) in southern Brazil over the last 19 years. As vector infestation was associated with climatic and environmental variables, HI data from the Brazilian Ministry of Health, climate data from the Giovanni web-based application, and environmental data from the Mapbiomas project were used in this study. Our results showed an expressive increase in the number of HI surveys in the municipalities confirming the vector presence, as compared to those in 2017. Environmental variables, such as urban infrastructure, precipitation, temperature, and humidity, were positively correlated with the Ae. aegypti HI. This was the first study to analyze Ae. aegypti HI surveys in municipalities of southern Brazil, and our findings could help in developing and planning disease control strategies to improve public health.
Visceral leishmaniasis is among the most neglected diseases in the world and especially affects poor populations of some developing or underdeveloped countries, with human disease being a factor in the occurrence of thousands of deaths every year. Visceral leishmaniasis affect domestic dogs, main reservoirs of the Leishmania parasite in urban environments. Thus, the aim of this study was to analyze the prevalence of canine visceral leishmaniasis in two non-endemic municipalities located in southern Santa Catarina, as well as to identify the main risk factors for infection in dogs. A cross-sectional study was carried out with dogs living in two Zoonoses Control Centers located in the cities of Tubarão and Criciúma. Blood samples were collected and analyzed by real-time PCR for detection of Leishmania infection. Clinical examination and evaluation of the characteristics of the canine population were also carried out. A total of 107 dogs were evaluated, of which 19% were positive for Leishmania, and 85% of the positive cases were asymptomatic. In conclusion, we highlight the detection of cases of canine visceral leishmaniasis in two cities that had not yet reported cases. The high rate of positive asymptomatic animals suggests the maintenance of the parasite in the environment.
23 October 2021 in Research, Society and Development
The family Psychodidae has a cosmopolitan distribution with members that occur in many habitats, mainly in humid environments, and is most diverse in the tropics. Subfamilies Sycoracinae and Phlebotominae have females with hematophagous habits and the latter studied more due to medical and veterinary interest, since it includes species that can transmit diseases to animals and humans. The knowledge about the sand fly fauna in a region is extremely important for adequate monitoring and control measures for leishmaniasis. Thus, the objective of this study was to characterize Psychodidae fauna in relation to richness, abundance and molecular identification of Leishmania spp. in sand flies in southern Santa Catarina, Brazil. The ollections were carried out between 2015 and 2016 in three cities in Santa Catarina, Brazil. Samples were taken near feeding places for domestic animals, urban forest and peridomicile areas. The insects were identified and female sand flies were submitted to molecular analysis to detect the presence of Leishmania spp.. A total of 4,200 insects were collected, 4,193 from the Sycoracinae subfamily and 7 Phlebotominae from the Nyssomyia neivai and Pintomyia fisheri species. Of the studied municipalities, sandflies were registered in Tubarão and Imaruí and the most frequent habitat was the peridomicile areas. No samples were positive for Leishmania spp. In conclusion, the work highlights the presence of two species of sandflies, which were recorded for the first time in southern Santa Catarina.