Declining Visceral Leishmaniasis in Malta

25 Abstract Aims: To study visceral leishmaniasis (VL) trends in Malta. Methods: Analysis of epidemiological and clinical trends, a veterinary questionnaire and questioning a canine laboratory testing facility. Results: A decline in VL in the past 25 years (1980-2005) was noted for both paediatric (p<0.001) and adult (p=0.002) populations. No seasonal variation in infection rates was found. Serological testing was reliable and a useful adjunct to bone marrow diagnosis. Treatment with sodium stibogluconate was highly effective and there were no permanent sequelae associated with disease or treatment. Vets are encountering less canine VL with no differences in localities Discussion: The decline in VL was paralleled by a decline in the stray canine reservoir population and by better management of canine infection in both sanctuaries and in domestic settings. Introduction Visceral Leishmaniasis (VL) is a chronic parasitic infection caused primarily by Leishmania donovani in the Old World, and by Leishmania amazonensis in the New World. It infects approximately 400,000 individuals annually worldwide, with a predilection towards early childhood. It is a chronic illness characterized by irregular fever, hepatosplenomegaly, pancytopenia and progressive weakness and emaciation, which can result in death if left untreated. VL is particularly important in the setting of coexistent and rising rates of Human Immunodeficiency Virus (HIV) infection and for example, in southern Europe 25-70% of adult VL cases are associated with coexistent HIV, and 1.5-9.5% of individuals with HIV suffer from newly acquired or reactivated VL. Paediatric cases have also been reported in which both organisms have been isolated. The Maltese Archipelago comprises the islands of Malta, Gozo, and Comino, and is situated in the center of the Mediterranean Sea, 93 km south of Sicily and 288 km north of North Africa. VL is endemic in the circum Mediterranean region, including Malta. As in most endemic areas, the vast majority of affected cases occur in the childhood population. Notification of human cases of leishmaniasis was made compulsory in Malta in 1946, making this country an ideal location for epidemiological studies of VL. Unfortunately, notification is not compulsory for canine infections. The diagnosis of VL was first made in Malta in 1911, and the cutaneous form of leishmaniasis is also found. The vector is the female sandfly Phlebotomus perniciosus and dogs continue to be the local reservoir for human Leishmania infection. Specific treatment for leishmaniasis was first instituted by Caronia of Catania in 1914, using a mixture of sodium antimony tartarate. Pentostam has been used for the treatment of leishmaniasis since the 1940s, and the current recommended dose of Pentostam is 20 mg/kg/day for 30 consecutive days. In an earlier study, we noted a declining trend in paediatric cases of VL. In this study, we reviewed Lieshmaniasis trends in Malta for all ages, with special focus on the paediatric age group, and relate this decreasing trend to present prevalence rates of infection in dogs and current treatment practices among Maltese vets. Cecil Vella MD, FRCPCH Department of Paediatrics, Mater Dei Hospital, Malta