Investigation of the spread of human visceral leishmaniasis in central Tunisia

The epidemiology, clinical patterns, and spatial spread of Mediterranean vi sceral leishmaniasis were retrospectively studied in central Tunisia. The c linical profile of the disease was typical of the Mediterranean infantile f orm, Malnutrition and associated infectious diseases were observed in 62.5% and 55% of cases, respectively. The case-fatality rate was 6.2% and resist ance to meglumine antimonate was observed in 1.6% of patients. The annual i ncidence of cases increased from similar to 10 cases per year before 1991 t o similar to 50 cases per year between 1992 and 1994. The cumulative incide nce was 133.7/100 000 among children aged <15 years. This increase was prec eded by 3 years of high mean annual rainfall in the region. The spatial dis tribution of the incidence of the infection through time showed an aggregat ion of cases in the northern part of the area where intensive agriculture p rojects took place during the last 10 years, leading to the establishment o f a stable Leishmania infantum transmission cycle below the Atlas mountain chains, and an evident tendency to a progressive extension to the south.