Detection of LeishmaniaDNA in Sand Flies (Diptera: Psychodidae) From a Cutaneous Leishmaniasis Outbreak Area in Northeastern Brazil

Cutaneous leishmaniasis (CL) by Leishmania braziliensisVianna (Kinetoplastida: Trypanosomatidae) is a widespread disease in the western hemisphere and Brazil is the country reporting the majority of the human cases each year. Several phlebotomine sand flies have been regarded as putative or proven vectors of L. braziliensisand multiple vectors may be involved in the transmission of this parasite in the same endemic foci. In this study, we tested a subset of female phlebotomine sand flies collected in the frame of a previous study conducted in a military training camp, where outbreaks of CL by L. braziliensishave sporadically been reported. In total, 1,807 female phlebotomine sand flies were tested (individually or in pools) by real-time PCR and a minimum infection rate of 0.9% (95% CI: 0.6–1.5%) was detected. Positive females belonged to the species Psychodopygus complexus(Mangabeira) or Psychodopygus wellcomeiFraiha, Shaw & Lainson (females of these species are morphologically indistinguishable), Trichopygomyia longispina(Mangabeira), and Sciopemyia sordellii(Shannon & Del Ponte) (Diptera: Psychodidae). By restriction enzyme analysis, 13 samples (nine of Ty. longispina, two of Ps. complexus/wellcomei, and two of Sc. sordellii) presented a HaeIII restriction profile identical to L. braziliensis. The results of this study reinforce the notion that multiple vectors may be involved in the transmission of L. braziliensisin a single focus, ultimately making the epidemiological picture more complex than currently recognized.