In the Spotlight - Leishmaniasis

Leishmania, protozoan parasites responsible for leishmaniasis, are transmitted to humans through the bite of sandflies, small insects resembling flies. Dogs are the classic reservoir for L. infantum. In the dermis, these Leishmania multiply within certain white blood cells and can then reach various tissues in the body, causing the symptoms of the disease. Human leishmaniasis manifests as ulcerative lesions of the skin (cutaneous leishmaniasis, CL) or visceral organs (visceral leishmaniasis, VL), following the migration of Leishmania parasites to the liver, spleen, or other deep organs.

Prevalence, as determined by sero-epidemiological screening surveys, varies between 3% and 28% depending on the region and the methods used. A trend toward an increase in the number of cases and geographical spread has been detected in recent years. Surveillance of human leishmaniasis in France is based on case reports submitted to the National Reference Center for Leishmania. It covers both autochthonous cases (241 cases reported between 1999 and 2009) and imported cases (721 cases reported during the same period). The annual incidence of autochthonous leishmaniasis is low, with an average of 22 cases per year, relating mainly to cases of LV (85%). Imported cases are more numerous (average annual incidence of 65.5 cases). They are primarily cases of LC (91%), and predominantly involve LC cases originating from the Maghreb, sub-Saharan Africa, and French Guiana.

Leishmaniasis appears to be firmly established in the Mediterranean departments of southern mainland France. In the epidemiological field, many unknowns remain regarding reservoirs, particularly the exact role of wild carnivores and the role of cats in the cycle. Finally, close monitoring of canine leishmaniasis is all the more necessary given that risk mapping suggests the possibility of the zoonosis spreading to the country’s Atlantic coast.