Cutaneous leishmaniasis in Sri Lanka: a study of possible animal reservoirs

SummaryBackgroundCutaneous leishmaniasis (CL) has been detected with increasing frequency in Sri Lanka in recent years. Leishmania donovani has been identified as the causative agent, but no information is available on vector(s) or reservoir(s). In this paper we present data on the screening of possible reservoirs for evidence of infection.MethodsPatients with clinically suggestive CL referred from dermatology clinics for a confirmatory diagnosis were examined parasitologically and by PCR. There were no immunocompromised patients and none had any visceralizing symptoms. Pet dogs and rodents from areas where the patients were diagnosed were similarly examined for infection.ResultsThe disease was confirmed in 86 of 116 patients. All positive patients were from rural areas of the country, closely associated with scrub jungles. Of the 151 dogs examined, two showed Leishmania amastigotes in Giemsa-stained smears, one in the skin and one in peripheral blood. None of the 47 rodents screened showed any evidence of Leishmania infection.ConclusionsThe evidence gathered shows that in Sri Lanka the disease is restricted to persons in the hinterland areas, with a possibility of it being a zoonosis. The detection of Leishmania amastigotes in two dogs is, however, not sufficient to incriminate them as reservoirs. More studies are needed for evidence of reservoir(s) and identification of behavior of the vector species in order to explain the atypical presentation of L. donovani in Sri Lanka.