[Human leishmaniases in Morocco: a nosogeographical diversity]

Abstract

Leishmaniases in Morocco are endemic diseases. Three forms of leishmaniasis are reported, visceral leishmaniasis, cutaneous leishmaniasis caused by Leishmania tropica and cutaneous lesions due to Leishmania major. Leishmania infantum, a common parasite inducing visceral leishmaniasis, was observed thereafter in cutaneous lesions. The first case of cutaneous leishmaniasis due to L. tropica was isolated since 1987. But, this parasite was shown to be more polymorphic with almost 8 zymodemes. However, these zymodemes are not all transmitted by Phlebotomus sergenti and not all isolated from human reservoir. Regarding the clinical aspect, cutaneous leishmaniasis with L. tropica is described as a single lesion starting as a nodule at the site of inoculation. A crust develops centrally which may fall away exposing an ulcer which heals gradually. The second cutaneous form is that caused by Leishmania major. It was known in villages located in the southern slopes of the Atlas Mountains. Clinically, the lesion is often severely inflamed and ulcerated and heals in 4-6 months. The epidemiologic cycle of this rural form, include Phlebotomus papatasi as the proven vector and a commensally rodent, Meriones shawi grandis as the reservoir. However, visceral leishmaniasis in Morocco has been known since 1921. It is especially located in the North. The responsible parasite is L. infantum MON 1. Two species of the sand fly are involved in the transmission of this form, P. ariasi and P. perniciosus. In infected man, the clinical signs are non-tender splenomegaly, with or without hepatomegaly, wasting and pallor of mucous membranes. Even though L. infantum MON1 is responsible of the disease, some canine cases were reported to be caused by Leishmania tropica.