[Systematic search for parasites among leprosy patients in Mali]

Practice of multidrug therapy in leprosy (combination Dapsone + Rifampicine + Clofazimine) established since 1981, has significantly reduced the incidence of the disease. However, immunosuppression due to treatment of multi-drugs therapy induced adverse reactions with glucocorticoid and the change in host immune response due to the leprosy itself, might increase the risk of parasitic infections. To test this hypothesis, we carried out a case-control study at the “Institut Marchoux” in Bamako. Stool and urine samples from all patients included in the study were examined for parasites identification. In addition, we performed thick and thin blood film to identify malaria infection and skin biopsy (snip) to detect onchocerciasis. A total of 121 cases of leprosy and 219 controls aged 10-84 years old were included in the study from March 1999 to February 2000. Sixty two percent (n = 121) of cases were treated with glucocorticoid. The prevalence of infection due to Entamoeba coli and Entamoeba histolytica were higher in cases than in controls (p = 0.02). The prevalence of infection due to hookworms was higher in cases than in controls. There was no difference of the infections to the other intestinal parasites. Three cases of cryptosporidiosis and one case of isosporosis were observed in leprosy group vs none in the control group. There was no significant difference between cases and controls with regard to prevalence of Schistosoma haematobium, Trichomonas vaginalis and Onchocera volvulus. The prevalence of Plasmodium falciparum was 4.9% (6/121) in the leprosy case and 7.8% (17/219) in the control group. In conclusion, despite the corticotherapy and immunosuppression due to leprosy, there was no difference in prevalence of pathogenic parasites. Entomoeba coli, Entamoeba histolytica which have significantly higher prevalence among the cases were not pathogen therefore there was no higher risk of severe intestinal parasitosis among the cases of leprosy. Treatment with glycocorticoid in patients with leprosy did not suggest any impact on the prevalence of this parasitic infections. In addition, multidrug therapy did not show any effect on the carriage of Plasmodium falciparum.