Buonfrate et al.
High burden of autochthonous arboviral infections during the summer season in Verona province, Italy, during 2025. J Infect. 2026;92:106730. doi:10.1016/j.jinf.2026.106730
In Veneto, a region in north-eastern Italy, an integrated surveillance system including human, vector, and environmental monitoring has been in place since 2010. From June to October, all patients presenting with fever and no clear signs of end-organ involvement (excluding the central nervous system) are tested for a panel of arboviral infections. Between June and September 2025, a study was conducted to estimate the frequency of autochthonous arboviral infections, stratified by virus type, diagnosed in patients presenting with fever to the Emergency Department of a hospital in the province of Verona, northern Italy.
A total of 108 patients were eligible for inclusion based on symptoms, of whom six were excluded because of age. Overall, 29 of 102 individuals were diagnosed with an arboviral infection. Among the tested patients, 3/99 had West Nile virus (WNV) infection, 4/101 had tick-borne encephalitis (TBE) virus infection, and 22/67 had chikungunya virus (CHIKV) infection.
Encephalitis was recorded as the clinical diagnosis in three arbovirus-positive cases, all of which were associated with TBE.
TBE cases were diagnosed between June and July. The first CHIKV case was diagnosed at the end of July, and cases continued to occur throughout September. WNV cases were detected in mid-August.
The study revealed that a substantial proportion of febrile illnesses during the summer season in the province of Verona was caused by autochthonous transmission of arboviruses.
None of the patients with TBE reported prior vaccination. These findings highlight the need to increase awareness and promote vaccination among individuals at epidemiological risk.