Riccò, M.
Epidemiology of tick-borne encephalitis in north-eastern Italy (2017-2020): international insights from national notification reports.
Acta Biomed. 2021;92(5):e20211229, doi:10.23750/abm.v92i5.11474.
In Italy, most TBE cases occur in northeastern regions, in the provinces of Trentino and Bolzano (the Triveneto) and in Veneto and Friuli-Venezia-Giulia. In these northeastern regions, an incidence rate of 0.38 cases per 100,000 inhabitants has been estimated. During the last few years, the overall incidence is rising.
In Triveneto, a total of 100 cases have been reported between 2017 and 2020, corresponding to an incidence of 0.35 per 100,000, which is relatively low as compared to the neighboring countries Slovenia, Austria and Switzerland. These relatively low numbers may be explained by the fact that only meningitis and encephalitis cases are notified but not diagnosed infections. Secondly, a high number of cases may not be registered when the reporting is not appropriate on patients’ discharge from hospital. Due to this dropout rate, a total of 152 cases may be estimated between 2017 and 2020, which corresponds to an incidence rate of 2.8 per 100,000 for Triveneto. The incidence in Trentino is estimated to reach 5.63 by local authorities, and the majority of cases is clustered in some hyperendemic foci. In fact, the yearly number of cases have doubled since 2006.
The author concluded that Italian data stress the potentially extensive underestimation for TBE virus infections, at least in northeastern Italy.