Resultados preliminares de um projeto sobre a ecologia dos flebotomíneos vetores de leishmaniose tegumenar no estado da Bahia / Preliminary results of a project on the ecology of the cutaneous leishmaniasis vectors phlebotominae in the State of Bahia

RESUMO

Preliminary data of a project about the ecology of the Phlebotominae (sandflies) in a tegumentary leishmaniasis area of coconut plantation in the south of the State of Bahia, Brazil are presented. There are 60 dwellings far of one another, where existed 31 dogs and 229 inhabitants. Among them 41.5 per cent were Montenegro positive; 37.5 per cent from these had scars of healed ulcers and 8.8 per cent had active ulcers. 53 per cent of the house had dogs from which 22 per cent were seropositive; from the 7 dogs with ulcers only 3 were seropositive. 14 per cent of the inspected house harboured sandflies inside them. During two years of observations 72 sentinels hamsters were maintened at houses of patients with leishmaniasis ulcers, but they did not get the infection. During two years of observation, monthly collectings of sandflies were made inside house, chicken pen, curral, tree trunks and open field around a house with a patient with leishmaniasis. The following results were already obtained about the vectors 5,614 specimens were identified as belonging to fourteen different species of sandflies. Among them Lutzomyia whitmani (92 per cent) and Lutzomyia intermedia (4.8 per cent) were the most abundant species. They are very anthropophilic and can be found inside houses and at peridomestic sites. Probably they are the principal vectors of the disease at domestic places. The other twelve species were less frequent and more found at sylvatic places in inspite they also bite the man. Generally the biting activity of most of the species of the area begins at 5 p.m. in the dusk and reaches its peak at 0 hour a.m., when begins declining until disapear at 7 a.m. L. whitmani was similarly collected with the same density in all lunar phases while L. intermedia was more abundant during the new moon phase. Most of the hundreds sandflies collected during the second year of observations, remains preserved in liquid nitrogen, watching for the adjustment of PCR molecular techniques to be processed for determination of the vector natural infection rates with leishmanias. Final results on all the project will be published as soon as the examination of such material has been processed.