Histochemical and molecular evaluation of the prevalence of Leishmania spp. in hematophagous insects

Abstract

The prevalence study of Leishmania spp. in hematophagous insects captured from the environment in bat roosts and pigeon nests, or feeding their hosts (cattle, pigs, horses, dogs and humans) in urban, peri-urban and rural areas, between 2012 and 2014. For this study, the amastigotes present in these insects were detected by histochemical and PCR techniques. Positive gene amplification for Leishmania was found in two horseflies of the species Tabanus importunus collected in the environment, and amastigote forms of Leishmania spp., as well as erythrocytes and leukocytes, were histochemically detected in one of that insect. The other analyzed insects were not positive by PCR our by direct parasitological examination. Only horseflies captured in urban and peri-urban areas were positive. During the collection, no phlebotomine sand flies were captured in rural areas far from the city limits. It can be concluded that the discovery of horseflies positive for Leishmania spp. in urban and peri-urban areas indicates the likelihood that urban areas and their surroundings provide vector parasites with an environment suitable for the spread and consequent perpetuation of the biological cycle of this protozoan.

Tabanids as possible pathogen vectors in Senegal (West Africa)

“…Trypanosoma theileri has been confirmed by amplifying the 18S gene and the ITS1 region. The existence of the L. donovani complex in tabanids has already been mentioned [32], but its involvement in the transmission cycle and the occurrence of disease has not been determined. Our study could not provide an explanation for the strong preponderance of Leishmania among Senegalese tabanids.…”