Leishmaniasis in Tuscany: investigation of hidden human cases and comparison with canine incidence

Abstract The Mediterranean basin hosts endemic areas for leishmaniasis, mainly attributable to the presence of sand flies. Leishmaniasis has gained importance in Europe due to climate change, globalisation and migration. For at least the last 10 years in Tuscany, Italy, there has been an important discrepancy between official notifications of visceral and cutaneous leishmaniasis cases in humans and the number of hospital admissions, highlighting an important underestimation, despite mandatory notification. Moreover, official reports have increased alarmingly in the last three years. Human leishmaniasis does not always require hospitalisation: it often presents cutaneous manifestations, whereas in the immunocompetent individual it may not occur at all. For this reason, it is reasonable to assume that the number of cases is higher than the number of hospitalisations. The project aims to investigate the underreporting of human leishmaniasis cases from 2014 to 2023 by analysing laboratory diagnoses (considering any laboratory test that, according to the Italian Ministry of Health guidelines, is useful to identify a ‘confirmed case’, thus serological tests; parasitological tests; culture tests; PCR). To estimate the extent of underreporting, the capture-recapture method will be used, taking into account laboratory data, official reports and hospital data. Subsequently, a comparison will be made with the incidence, in the same territory, of veterinary cases, particularly in dogs, using data obtained from the Lazio-Tuscany Zooprophylactic Institute, to compare the trend of human and canine cases over time. Analyses are in progress and the results will be presented at the conference. Poor surveillance leads to ineffective prevention policies. The impact of the project is to strengthen the leishmaniasis surveillance system in Tuscany in order to reinforce prevention systems and face emergencies. Key messages • Due to climate change, globalization, and migration, there has been an increase in diagnoses of vector-borne diseases, including Leishmaniasis. • Leishmaniasis surveillance need to be strengthened in order to enhance prevention systems and address emergencies.