Thirty years of cutaneous leishmaniasis in Tadla-Azilal focus, Morocco

Parasite Epidemiol Control. 2019 Jan 31:4:e00091. doi: 10.1016/j.parepi.2019.e00091. eCollection 2019 Feb.

Abstract

Cutaneous leishmaniasis (CL) due to Leishmania tropica is a major health problem in Tadla-Azilal focus, Morocco, where the first case was registered, here, in one locality named Tanant in 1987. So far, CL remains endemic and largely widespread. The objective of this study was to analyze the current eco-epidemiological situation after thirty years of active transmission. Data used are the official ones, obtained from the Moroccan Ministry of Health. Between 1998 and 2015, 5518 CL cases were registered in three provinces; Azilal, Béni Mellal and Fquih Ben Salah. CL has spread, from the historical focus in Azilal along two axes; one to the Northeastern Mountains and the other to the Northwestern plains. CL infected both genders and all ages, with large number of women (53%) and children (75% had <9 years old). More interestingly, age range at risk was larger within females than males, and this difference was more pronounced in Fquih Ben Salah where the disease had newly emerged. Similarly, age ranges at risk were larger and fluctuated significantly each year particularly in new emerging areas in Béni Mellal and Fquih Ben Salah. All these variations may testify, at least in part, to the process of acquiring immunity. Altitude structured CL spatiotemporal distribution. CL was more prevalent in two altitudes ranges; 400-500 m and 800-900 m. The situation and duration of period of diagnostic of CL varied largely according to the altitude. These different scenarios could be related to the seasonal dynamics of vector populations.

Keywords: Age structure; Altitude; Cutaneous leishmaniasis; Morocco; Space-time distribution; Tadla-Azilal.