Dinâmica de anofelinos na transmissão da malária no Distrito do Coração, Município de Macapá, Amapá, Brasil

Abstract

The Anopheles species are insects belonging to order Diptera, suborder Nematocera, Family Culicidae, subfamily Anophelinae and genus Anopheles Meigen 18 18, and are popularly known as mosquitoes, gadflies or gnats. In the Americas, malaria is transmitted in 21 countries, where it is estimated that approximately 203 million people are at risk of contracting this disease. Brazil is responsible for the largest number of cases, with 50.7% of total registrations, corresponding about 500.000 cases per year. Of these, approximately 99.5% of cases occur in the Amazonian, comprising the states of Acre, Rondonia, Amazonas, Roraima, Amapa, Para, Maranhão, Mato Grosso and Tocantins. For understanding the dynamics of malaria transmission in an area of study is necessary to know the entomological parameters of Anopheles species, such as diversity and population density, biting activity; behavior exophilic, endophily, anthropophilic, bestiality and natural infection. Therefore, the goal was to analyze the entomological factors involved in the dynamics of malaria transmission correlating them with environmental variables. The current study was conducted in the Distrito do Coração, located in "Duca Serra" Highway, 13 km, municipality of Macapa city, state of Amapá, Brazil. The collections of specimens in the Distrito do Coração were conducted fiom December 2010 to November 201 1, comprising less and more rainy periods. Samples were collected monthly, with three days of uninterrupted catch using attractive humans with protection. In addition, there were four collections of twelve hours and four in environments anthropophilic and zoophilic. The mosquitoes collected were placed in plastic cups with site identification, date, time and mode of capture. ARer the collections the mosquitoes were identified, associating them with the air temperature relative humidity and rainfall, the time of highest biting activity, the degree of endophily exophilic behavior, the parameters of anthropophilic and zoophilic. The dissection of the ovary of the species collected were carried out for estimated the parous rates of females, as were analyzed the rate of infectivity for Piamodium species using PCR technique. We obtained a total of nine species diversity for 1,689 individuals collected. The most abundant species were A. darlingi, A. brazzlienszs and A. marajoara. The density was higher in the month of September, in the less rainy period. There was a multimodal behavior of biting activity for the predominant species, with a higher leve1 of exophilic and anthropophilic. The rate of attraction to mosquitoes per madhour showed no significant correlation with climatic variables (air temperature, relative humidity and rainfall). This lack of correlation may be due to the low density and variability in the abundance of mosquitoes between plots. The three predominant species present high parous rate. A11 samples (397 pools) were negative for Plmodium spp. Of the three most abundant species in this study, two are important vectors of malaria in the region. Considering this aspect, the Distrito do Coração can be considered a highly vulnerable to the development of outbreaks of malaria, therefore, require urgent control measures to be implemented in this district in order to prevent outbreaks and/or malaria epidemics.