Epidemiological Status of Visceral Leishmaniasis in Iran: Experiences and Review of Literature

Abstract

Background: The Mediterranean form of visceral leishmaniasis (VL), or kala-azar, is a potentially fatal vector-borne zoonotic disease. At the present time, VL caused by Leishmania infantum is recognized as an important parasitic disease in Iran. Objective: The aim of the study was to review the epidemiological aspects of VL in Iran during 1996-2010. Methods: Twenty seven eligible journal articles on VL epidemiological aspects were indexed in electronic databases (ISI and MEDLINE) from 1996 to 2010 and selected for this review accompanied by my personal experiences over two decades. For the detection of VL in humans and animal reservoir hosts, anti-Leishmania antibodies were detected using direct agglutination test (DAT). Parasitological examinations were performed on suspected VL patients and all captured wild canines and rodents. Different molecular methods were used for identification of Leishmania species isolated from infected humans, animal reservoirs, and vectors. Results: More than 3000 cases of symptomatic VL were detected in 31 provinces of Iran from 1996 to 2010. The majority of VL cases (92.8%) were found among children up to 12 years old. DAT surveillance could help decrease mortality and morbidity in VL endemic areas of Iran. The principal animal reservoir hosts of the infection were domestic and wild canines. Infections of man and desert rodents were accidental. Phlebotomus kandelakii; P. perfiliewi in northwest Iran; and P. major, P. keshishiani, and P. alexandri in southern parts of Iran were parasitologically or molecularly shown to be the principal VL vectors. Conclusion: The Mediterranean form of VL is a serious zoonotic disease that occurs sporadically in all geographical zones of Iran except northwestern and southern Iran, where the disease is endemic