Entomological, parasitological and molecular investigations in a new focus of cutaneous leishmaniasis in Youssoufia region, Morocco.

BACKGROUND AND AIMS: Leishmaniasis is a neglected tropical infection caused by Leishmania parasite that affect human and animal. In Morocco, the cutaneous leishmaniasis has spread substantially to the new areas. The surveillance limited to active foci may underestimate the occurrence of cutaneous leishmaniasis (CL). This study aims to investigate the local transmission of CL in rural districts of Youssoufia province, central Morocco, as a potential focus of CL. METHODS: For this purpose, parasitological, molecular and entomological investigations were carried out in this area. Data collection concerns potential vectors and human cases. Thus, 402 patients were examined for suspected leishmaniasis lesions in three localities of the province of Youssoufia. In these same localities, 983 sand flies were collected by CDC light traps and sticky paper during one-night per month during 6 months. These sand flies were all identified morphologically using the Moroccan identification key. RESULTS: The results showed that among the 25 skin lesions detected in a population of 402 individuals, 18 were confirmed by kDNA nested PCR as CL positive patients, of which only 25% were positive by direct examination. Leishmania tropica and Leishmania major were identified as causative agents of CL in the study area. Direct parasitological examination showed a low sensitivity (27.78%), especially for L. major, although its specificity was evaluated at 100%. Regarding entomological results, both genera of the Moroccan sand fly were collected in the study area: Genus/Phlebotomus (75.28%) and Sergentomyia (24.72%). Phlebotomus (P) papatasi, the proven vector of L. major, was the most abundant species (33.98%), followed by Paralongicollum sergenti (22.58%), the confirmed vector of L. tropica; while Sergentomyia (S) minuta, P. longicuspis, S. fallax and P. kazeruni were collected with, respectively, 17.60%, 16.99%, 7.12% and 1.73%. CONCLUSION: This study constitutes the first report of CL in the study areas, as well as the coexistence of L. tropica and L. major in these rural localities. Local transmission of CL is highly probable, as indicated by the prevalence of the two proven vectors of L. major and L. tropica. To control the spread of this disease, our results suggest the use of highly sensitive molecular methods to detect CL cases in potential leishmaniasis foci, which will improve surveillance.

Determinants of anthroponotic cutaneous leishmaniasis by case-control study in Morocco.

Leishmaniasis is endemic in Morocco where both cutaneous and visceral forms coexist. To date, anthroponotic cutaneous leishmaniasis (ACL) determinants remain poorly investigated in Morocco. However, the disease risk factors identification is vital to determine the specific preventive process. In this aim, a case-control study was conducted in the main active ACL foci in central Morocco. Epidemiological data were extracted from bulletins, registers and annual reports of the regional direction of Health offices. The socioeconomic and environmental data were collected from epidemiological surveys, completed by a questionnaire intended for accessible positive population and control people selected from the cases' entourage. The study included 258 cases and 395 controls. Our results showed that many socioeconomic factors were associated with ACL in Morocco such as the rural habitation (OR = 4.163; 95% CI: 2.91-5.96), movement to endemic area (OR = 4.53; 95% CI: 3.03-6.77), provenance from leishmaniasis foci (in Essaouira focus OR = 5.34; 95% CI: 1.19-24.03) and poverty. In addition, environmental factors like proximity of vegetation (OR = 2.45; 95% CI: 1.14-5.25), poor domestic hygiene, particularly the absence of sewage system/waste management (OR = 1.63; 95% CI: 1.35-1.96), and presence of animals (OR = 2.67; 95% CI: 1.14-5.25) increase the risk of ACL in Morocco. Except for Matrimonial status (married people, OR = 4.11; 95% CI: 1.80-9.41), there is however no significant association of the disease with the other socio-demographic factors in the study area (p>0.05). These several risk factors must be taken in consideration to prevent this disease through multidisciplinary collaboration and community participation.

Climate Change Influences on the Potential Distribution of the Sand Fly Phlebotomus sergenti, Vector of Leishmania tropica in Morocco.

BACKGROUND: Leishmaniases are a vector-borne disease, re-emerging in several regions of the world posing a burden on public health. As other vector-borne diseases, climate change is a crucial factor affecting the evolution of leishmaniasis. In Morocco, anthroponotic cutaneous leishmaniasis (ACL) is widespread geographically as many foci across the country, mainly in central Morocco. The objective of this study is to evaluate the potential impacts of climate change on the distribution of ACL due to Leishmania tropica, and its corresponding vector Phlebotomus sergenti in Morocco. METHODS: Using Ecological Niche Modeling (ENM) tool, the estimated geographical range shift of L. tropica and P. sergenti by 2050 was projected under two Representative's Concentration's Pathways (RCPs) to be 2.6 and RCP 8.5 respectively. P. sergenti records were obtained from field collections of the laboratory team and previously published entomological observations, while, epidemiological data for L. tropica were obtained from Moroccan Ministry of Health reports. RESULTS: Our models under present-day conditions indicated a probable expansion for L. tropica as well as for its vector in Morocco, P. sergenti. It showed a concentrated distribution in the west-central and northern area of Morocco. Future predictions anticipate expansion into areas not identified as suitable for P. sergenti under present conditions, particularly in northern and southeastern areas of Morocco. L. tropica is also expected to have high expansion in southern areas for the next 30 years in Morocco. CONCLUSION: This indicates that L. tropica and P. sergenti will continue to find suitable climate conditions in the future. A higher abundance of P. sergenti may indeed result in a higher transmission risk of ACL. This information is essential in developing a control plan for ACL in Morocco. However, future investigations on L. tropica reservoirs are needed to confirm our predictions.