HUMAN BITING RHYTHM, BLOOD MEAL SOURCES IDENTIFICATION, AND DETECTION LEISHMANIA PARASITES IN SANDFLY SPECIES IN OCHOLLO, A CUTANEOUS LEISHMANIASIS HOTSPOT IN SOUTHWEST ETHIOPIA

Abstract

Ochollo is a cutaneous leishmaniasis (CL) hotspot Kebele in the southwest Ethiopia. The study was aimed on the human biting rhythm, blood meal sources identification, and detection of Leishmania parasite in sandfly species in Ochollo Kebele, a CL hotspot in southwest Ethiopia. Three entomological techniques such as human landing catches (HLC), Centers for Disease Control and Prevention (CDC) light traps and sticky traps (ST) were employed to collect sandflies. The Kebele was clustered into nine sub-Kebeles and eight houses were randomly selected from each sub-Kebele. Seventy two randomly selected houses and ten available caves were used for CDC light trap and ST collection of sandflies.HLC was done in another four houses (two close to caves, two far from caves).Bloodmeal sources of Phlebotomus species was determined using polymerase chain reaction (PCR) and the positive specimens were sequenced to determine the host species. Freshly fed sandflies were screened for Leishmania parasite detection by kDNA rt-PCR. A total of 11,488 sandfly, 36% (4108) Phlebotomus, and 64% (7380) Sergentomyia were collected indoors, outdoor on walls and inside caves. Among the indoor collected sandflies, Phlebotomus accounted 33% (1413 of the 4283), while Sergentomyia accounted for 67%. Phlebotomus pedifer (89.5%; 619 of the 692) and P. gibiensis (10.5%; 73 of 692) were the two Phlebotomus species identified. Among the 414 blood fed Phlebotomus processed for blood meal sources determination, 311 (75%) samples were positive for Cytochrome b gene amplification. Among the positive specimens, 73% (227 of 311) had blood meal from 19 different bloodmeal sources, and human was the dominant blood meal source of P. pedifer in the study area. About 4.4% (6 of 136) human and 14% (1 of 7) Acomys ngurui blood meals were positive for Leishmania kDNA. Phlebotomus pedifer was the predominant (150; 93%) species collected by HLC catches with majority from indoors. The peak biting hours were 20:00-22:00indoor and 23:00-24:00outdoor. The current investigation on blood meal source determination calls for a study to assess the role of both wild and domestic animals in disease transmission.