Malária no Maranhão: aspectos bioecológicos de espécies de Anopheles Meigen, 1818 e dinâmica de transmissão nos municípios de Buriticupu e São José de Ribamar.

Abstract

Entomological studies were conducted, based on data from the municipalities of San Jose and Buriticupu Ribamar, in the state of Maranhão, in order to equate entomological parameters related to the dynamics of malaria transmission and control. Collections of mosquitoes were performed in intra, peri and extradomicílio from 18h to 06h, in the period 2006 to 2011. Also conducted sampling of immature forms and data were obtained on density of Anopheles species, diversity of macrophytes and limnological data, with emphasis on physical and chemical aspects of the water. The mosquitoes were analyzed for infection by the plasmodium and the diagnosis of blood ingested. In the city of Buriticupu nine species were collected and 2,832 copies in total. Considering the most frequent species, Anopheles darlingi accounted for 63.59% of the sample, 22.96% Anopheles albitarsis latus senso and Anopheles oswaldoi 5.67%. When one considers the collections in intra, peri and extradomicílio it appears that the three species showed very similar percentages in all three environments, respectively, about 23%, 53% and 22%. In the coastal area of San José de Ribamar were collected only 75 specimens of adults, and 35 specimens of A. aquasalis 23 A. albitarsis latus,senso and 5 A. darlingi. Regarding immature, Buriticupu 130 specimens were captured and A. darlingi accounted for 60% of samples, and A. albitarsis latus senso 24.61%. In San José de Ribamar 62 larvae were captured with 61.29% of A. aquasalis and 22.59% of A. albitarsis latus senso. The data showed that dietary source A. darlingi and A. aquasalis had more relation with the human host. The PCR data were positive for Plasmodium vivax and P. falciparum, and were detected A. darlingi, A. albitarsis latus senso, A. oswaldoi and A. nuneztovari infected species. The values of Minimum Rate of Infection of the four species were 2.8, 2.2, 4.6 and 8.3, respectively. Considering the two localities studied, A. darlingi, A. aquasalis, A. albitarsis latus senso and A. oswaldoi were found predominantly in animal sheds and showed anthropophilic and zoophilic behavior. These species showed among hosts eclectic behavior. The Anopheles density on São Luis island was low, but the area is endemic for the disease and the presence of A. darlingi in Guarapiranga was detected again after had been recorded in 1940. In the characterization of breeding, as the associated vegetation, five genera were detected in each municipality, only the genus Nymphaea common both sites.