West Nile virus (WNV) and Usutu virus (USUV) are neurotropic mosquito-borne orthoflaviviruses maintained in an enzootic cycle, in which birds are amplifying/reservoir hosts, while humans and equids are dead-end hosts. As northern Italy, especially the Veneto Region, is considered an endemic area for WNV and USUV circulation, a surveillance plan based on a One Health approach has been implemented since 2008. This work reports the results of entomological, veterinary and human surveillances for WNV and USUV in the Veneto Region in 2022 and 2023, through virological and/or serological examinations. In 2022, 531 human WNV infections were recorded, and 93,213 mosquitoes and 2193 birds were virologically tested, showing infection rates (IRs) of 4.85% and 8.30%, respectively. The surveillance effort in 2023 provided these results: 56 human WNV infections were confirmed, and 133,648 mosquitoes and 1812 birds were virologically tested, showing IRs of 1.78% and 4.69%, respectively. This work highlights the exceptional circulation of WNV in the Veneto Region, due to the new re-introduction of WNV lineage 1 and co-circulation with WNV lineage 2. This paper confirms the efficacy of integrated surveillance for early warning of viral circulation and gives new insights about avian hosts involved in the enzootic cycle of orthoflavivirus in the endemic region of Italy.

Jingmen tick virus (JMTV) is a novel flavi-like virus first identified in 2010 in Rhipicephalus microplus in the Jingmen region of Hubei Province, China and has been reported in different Asian countries, Central and South America, Africa, and Europe. Beyond ticks, JMTV has been detected in a range of other arthropods and in vertebrate hosts. In humans, JMTV has been found in patients with Crimean-Congo hemorrhagic fever in Kosovo and Turkey, and in febrile patients with a history of tick bites in China, suggesting it may be a novel human pathogen. To investigate the presence of JMTV in Italy, we developed a One-step real-time RT-PCR assay and applied it to individually screen 1150 ticks collected from northeastern, central, and southern Italy. JMTV RNA was detected in multiple tick species, including Ixodes ricinus, Rhipicephalus bursa, Rhipicephalus sanguineus s.l., Dermacentor marginatus, and Hyalomma marginatum with a prevalence ranging from 0.52% to 18.42% in questing ticks. The detection of JMTV in ticks from all surveyed areas, indicates that the virus is geographically widespread in Italy. These findings highlight the need for comprehensive surveillance strategies to identify new areas of active virus circulation and to investigate the potential impact of JMTV on public health.

Aedes invasive mosquito (AIM) species are expanding worldwide, increasing the risk of arbovirus introduction and transmission. Points of Entry (PoEs), including airports and seaports, represent critical gateways for the introduction and spread of invasive vectors through international passenger and cargo traffic. This study evaluated the AIM long-term dynamics at three major PoEs (Treviso Airport, Venice Airport, and Venice Port) in northeastern Italy (Veneto region) between 2018 and 2024 through an integrated entomological surveillance programme designed to collect AIMs (adults and eggs) throughout the seasonal activity (June–October). Mosquitoes were identified morphologically and, where required, by molecular analyses. Aedes albopictus was the dominant AIM throughout the study period (eggs N = 96,192, adults N = 14,231), being detected at all three study sites and showing consistent interannual and seasonal dynamics, with peak abundance during summer despite routine vector control interventions. Aedes koreicus was detected at two of the three study sites, namely Venice and Treviso airports (eggs N = 1, adults N = 3). Phylogenetic analyses based on COI indicated that these specimens belonged to a distinct European lineage, revealing genetic diversity among European populations of Ae. koreicus. No evidence of newly established AIMs was found during the surveillance period. These findings highlight the importance of long-term surveillance at PoEs for the early detection of AIMs, monitoring temporal changes in established vector populations, and supporting integrated control and surveillance strategies to reduce the risk of vector establishment and mosquito-borne disease transmission.