Epidemiological update of human cases of Toscana Virus infections in the Emilia-Romagna region in the period 2010-2022

Background and Objective: Toscana virus (TOSV) infection often occurs asymptomatically or with mild symptoms (asthenia, fever, headache) but it can also generate neurological clinical pictures (meningitis, encephalitis). This epidemiological update describes the trend of human confirmed cases of tosv in the period 2010-2022 in Emilia-Romagna region and the main characteristics of the population involved. Methods: The elaborations refer to the notifications of infectious diseases, on the regional web-based system “Surveillance of Infectious Diseases” (SMI), provided by ministerial decree 15/12/90, based on the Arboviroses surveillance system (dgr 531/2022) of the 2022 Emilia-Romagna regional plan for the surveillance and control of Arboviroses (PSCA). Results: In the period 2010-2022, 568 confirmed cases of TOSV were notified. The trend of reports of TOSV infections was variable: a minimum number of cases in 2011 (15 cases) and two peaks in 2013 and 2022 (88 cases and 109 cases, respectively). During the period 2010-2021 we observed a peak of cases in August, in 2022 the peak was observed one month later. In all years, TOSV infection was prevalent in males. In terms of incidence the most affected age group was 25-44 years followed by 45-64 years and over 65. Referring to 2022, we observed a wide overlap between the areas where more human TOSV infections were notified and the areas where more sandflies were caught. During the period 2013-2022 TOSV infections manifested mainly with meningitis, except in 2018 when we recorded more cases of encephalitis. Conclusions: TOSV infections represent an emerging public health concern. The aim of the PSCA and the Emilia-Romagna region surveillance system is to rapidly identify TOSV infections’ cases and to stimulate behaviors aimed at individual protection and prevention of the vector’s spread in order to correctly invest future resources.