[Study of phlebotomines sand fly wildlife suburban location of Bamako (Mali) presence of Phlebotomus (Phlebotomus) duboscqi]

Distribution and Diversity of Sand Fly Species (Diptera: Psychodidae, Phlebotominae) in Two Geoclimatic Zones of Chad

Leishmaniasis transmitted by sandflies is an important vector-borne disease. In Chad, information on sandflies is outdated, and so this study was designed to update the sandfly fauna. Sandflies were collected in five health districts representing two geoclimatic zones using sticky traps and pyrethrum sprays in indoor and peridomestic habitats between September 2019 and December 2020. All collected sandfly specimens were identified based on species-level morphological characters. A total of 2,015 specimens belonging to 13 species of sandflies (one Phlebotomus and twelve Sergentomyia) were collected and identified. The vector of human cutaneous leishmaniasis, Phlebotomus duboscqi, represents 0.65% of all collected sandflies and is the only representative of the Phlebotomus genus to be collected predominantly inside human dwellings. Phlebotomus orientalis, the vector of visceral leishmaniasis previously collected in Chad in 1976 was not found in this study. Sergentomyia clydei, Sergentomyia schwetzi, Sergentomyia antennata and Sergentomyia africana were the most abundant species collected with 44.71%; 22.73%; 16.03% and 11.17%, respectively. Sergentomyia schwetzi and Sergentomyia dubia, the two species involved in the transmission of canine leishmaniasis, were found in five and four study sites respectively. According to our results, the sandfly fauna of the two geoclimatic zones of Chad is comprised of 13 species. Our data showed that, unlike P. orientalis which was not found, P. duboscqi is present in four of the five sites surveyed. Therefore, these areas are at risk and remain potential foci of cutaneous leishmaniasis. However, the need for further studies such as vector species detection, their seasonal fluctuations and their vector competence.

Epidemiology of the outbreak, vectors and reservoirs of cutaneous leishmaniasis in Mali: A systematic review and meta-analysis

OBJECTIVE

To compile available data and to estimate the burden, characteristics and risks factors of cutaneous leishmaniasis (CL) in Mali.

METHODS

Articles in English and French were searched in Hinari, Google scholar and PubMed. Unpublished studies were identified by searching in Google.com. Terms used were cutaneous leishmaniasis Mali; Leishmaniasis Mali, Leishmania major Mali; or Phlebotomus Mali or Sergentomyia Mali. We select descriptive studies on CL and sandflies in Mali. Data were extracted and checked by the author, then analyzed by region, by study population and type of biological tests, meta-analysis approach with STATA software was used.

RESULTS

Nineteen published (n = 19) and three unpublished were included. CL epidemiology was characterized by occurrence of clinical cases in different areas of Mali, outbreaks restricted to known areas of transmission and isolated cases diagnosed in travelers. In endemic areas, population at risk are young age persons, farmers, ranchers, housewives, teachers and military personnel. The annual incidence ranged from 290 to 580 cases of CL. Leishmania major is the main species encountered throughout the country (North Savanna, Sahel and Sub-Saharan areas), and Phlebotomus duboscqi has been identified as the vector and Sergentomyia (Spelaeomyia) darlingi as possible vector. The overall estimated prevalence of positive LST (Leishmanin Skin Test) was 22.1%. The overall frequency of CL disease among suspected cases was 40.3%.

CONCLUSIONS

Although descriptive, hospital-based and cross-sectional studies are robust enough to determine the extent of CL in Mali; future well-designed eco-epidemiological studies at a nationwide scale are needed to fully characterize CL epidemiology and risk factors in Mali.

Diversity of Sand Flies (Diptera: Psychodidae: Phlebotominae) in Two Different Eco-Climatic and Endemic Zones of Cutaneous Leishmaniasis in Mali, West Africa

Being the only established vectors of the protozoan parasites of the genus Leishmania, sand flies have become very important in all countries where leishmaniasis exists. To better understand the sand fly fauna, a taxonomic inventory study was carried out between January and March 2012 in Soudan savannah (Boundioba, Sikasso) and Sahelian (Tieneguebougou, Koulikoro) areas of Mali. CDC light traps were used to collect the sand flies. Collected sand flies specimens were cleaned with lacto-phenol and examined under a light microscope for species identification. In total, 14 species belonging to the genera Phlebotomus and Sergentomyia were identified. The genus Sergentomyia constituted 98.05% of collected sand flies versus 1.95% for the genus Phlebotomus. The most abundant species were Sergentomyia dubia Parrot, Mornet, & Cadenat, Sergentomyia shwetzi, Sergentomyia clydei Sinton, and Sergentomyia antennata Newstead. In Boundioba, the genus Phlebotomus was represented by two species (Phlebotomus duboscqi Neveu-Lemaire and Phlebotomus rodhaini Parrot), whereas only one species, Ph. duboscqi, was captured in Tieneguebougou. For the first time, three new species, Sergentomyia madagascariensis, Sergentomyia congolensis, and Sergentomyia dureni, were identified in Mali. More investigations are needed for a better entomological assessment of the transmission of cutaneous leishmaniasis in the different eco-climatic zones of Mali.