HELMINTHS OF PUBLIC HEALTH INTEREST ON THE EXTERNAL SURFACE OF DIPTERA (INSECTA) IN FEIRA DE SANTANA AND SALVADOR, BA

Abstract

Insects of the order Diptera are often associated with several conditions of poor health quality, waste deposits and sewage ditches, conditions that may cause contact with stages of parasites of health interest, that can carry the same on their body surface, favoring the spread of these agents. We propose to detect protozoa and helminths on outer surface of sinantropic Diptera in two cities in the State of Bahia. The collection of the flies was carried out from May 2012 to August 2014 in a public school, at a University campus in Feira de Santana and in a park in Salvador in an area covered with dense vegetation. In these sites traps were installed for a total of 15 collections. After 48 hours following the assembling of the traps, the content was taken to the lab for parasitological examination. The flies were stored individually in the microtubes containing 5 mL of distilled water, agitated for 2 minutes and removed from the tubes afterwards. The liquid washed from the outer surfaces were centrifuged at the 1650 g for five minutes, eliminating the supernatant. For the examination and identification of the organisms, 50 µL of the sediment was observed in an optical microscope between slide and cover slip in duplicate. During the study period 778 specimens of fly were captured for the analysis. The majority of the specimens were Muscidae (60,6%), Fanniidae (20,7%), Calliphoridae (10,3%) and Sarcophagidae (8,3%). Of the 778 samples analyzed, 15 (1,9%) were positive parasites: Ascaris, Schistosoma, hookworms, Taenia, Enterobius, Strongyloides and Trichuris. There was no association between the family of Diptera and the parasitological examination result, no correlation between temperature, humidity and rainfall and relative abundance of families of flies, however, 60% of the parasitological examination result was influenced by the climatic variables, with significance to the rainfall, which ranged from 0.4 to 29.0 mm in flies carrying parasites. The study reveals that the families Sarcophagidae, Fanniidae and Calliphoridae are mechanic vectors of human parasites and other animals in the areas studied. This reveals the importance to control these vectors to minimize the risk factors of the infections.