First Human Case of West Nile Virus in Abruzzo Region

: Source: Istituto Superiore di Sanità

On August 27, 2024, a human case of West Nile Virus (WNV) infection was confirmed in Abruzzo (in the province of Chieti).

The individual, a resident of San Salvo, showed nonspecific febrile symptoms unresponsive to antipyretic treatment, and tested negative for other viral infections. Screening and confirmation tests were carried out by the Regional Reference Laboratory for Arbovirus Diagnosis at the Istituto Zooprofilattico Sperimentale of Abruzzo and Molise, Teramo (IZS-AM).

Entomological surveillance, coordinated by the Entomology department of IZS-AM in collaboration with veterinary services, had already detected the West Nile virus in a mosquito pool on 7 June 2024 in the province of Chieti, providing early warning of the virus circulation in Abruzzo. The National Reference Centre for the Study and Diagnosis of Exotic Animal Diseases (CESME) has been carrying out WNV surveillance in Abruzzo region since 2019.

In the following months, the veterinary surveillance, implemented on the regional territory in compliance with the "National Plan for the Prevention, Surveillance and Response to Arboviruses (PNA) 2020-2025" and the "Regional Operational Plan for West Nile Disease and Usutu Virus Surveillance in Abruzzo" (DGR no. 479 of 05/08/2020), gave the opportunity to confirm WNV circulation in other municipalities in the province of Chieti in pools of mosquitoes, birds and equids.

The regional Arbovirus surveillance system has therefore allowed the early detection of the virus and the consequent rapid activation of the necessary control measures to limit the transmission of the virus to humans.

The control measures outlined in the PNA were implemented through collaboration among various institutions, including the Regional Health Department, Regional Blood Centre, Regional Transplant Centre, Public Health Epidemiology and Hygiene Service, Veterinary Service of the Lanciano-Vasto-Chieti Prevention Department, and the affected municipalities (Vasto, Casalbordino, Lanciano, San Salvo), following the One Health approach.

According to the National Arbovirus Plan 2020-2025, to reduce exposure to West Nile Virus it is necessary to promptly implement the main vector control measures in the areas where viral circulation has been detected:

Strengthen larval control in public areas and healthcare facilities.

Use adulticides in a controlled and targeted manner, for example in the case of large evening events in outdoor areas.

To inform citizens about protective measures, such as repellents and mosquito nets.

To encourage citizens to prevent water stagnation in private properties, such as gardens and cemeteries, to avoid mosquito’s proliferation.

The Ministry of Health through two Directorates, the former General Directorate of Prevention (formerly DGPREV) and the former General Directorate of Animal Health and Veterinary Drugs (formerly DGSAF), coordinates human and veterinary surveillance activities. These efforts are supported, for their respective fields, by the Department of Infectious Diseases of the National Institute of Health and CESME at the Istituto Zooprofilattico Sperimentale of Abruzzo and Molise.

Source