# Integrated Surveillance of Viral Pathogens in Wild Boars: Serological and Molecular Insight in Southern Italy

## TL;DR

This study tracks viruses in wild boars in Southern Italy to understand their role in spreading diseases to farm animals and humans.

## Contribution

The study uses a multi-pathogen approach across a wide geographical area to monitor virus circulation in wild boars.

## Key findings

- Influenza A viruses and PCV-2 were actively present in wild boars.
- Seropositivity for IAVs, FLVs, and ADV indicated past exposure to these viruses.
- Wild boars serve as effective sentinels for virus surveillance in the region.

## Abstract

Wild animals can carry viruses that may affect both people and farm animals, so it is important to monitor their health. Wild boars are especially relevant because they live in large numbers and often come into contact with domestic pigs in rural areas. This study examined wild boars from Southern Italy for Influenza A viruses (IAVs), Circovirus, Aujeszky’s disease virus (ADV) and Flaviviruses (FLVs), which can cause illness in pigs and other wild animals. The analyses showed that influenza viruses and Circovirus type 2 (PCV-2) were actively present in wild boars, while antibodies revealed past exposure to Influenza, FLVs, and ADV. These findings show that wild boars can act as sentinels, meaning they help signal which viruses are circulating in the environment. Understanding this circulation is valuable because it helps protect farm animals and reduces risks to human health. By keeping track of viruses in wildlife, society can be better prepared to prevent outbreaks and safeguard both agriculture and public health.

The circulation of viruses of medical and veterinary importance is monitored to evaluate risks to both human and animal health. Among the species most commonly used in surveillance programs, the wild boar (Sus scrofa) plays a key role due to its high population density and its contacts with rural swine herds in the areas under investigation. In the present study, molecular (real-time PCR) and serological analyses were conducted on wild boar samples collected in the regions of Apulia, Basilicata, Campania, and Calabria. Specifically, molecular detection was applied to IAVs, FLVs, and Porcine PCV-2, while serological testing was used to assess exposure to IAVs, FLVs, and ADV. Serological results showed an 8.31% positivity for IAVs, whereas viral presence detected by PCR was 1.17%. No active infections were detected for WNV, with only a single seropositive sample (0.30%), while ADV showed a seroprevalence of 2.61%. PCV-2 was detected exclusively by molecular analysis in 66 out of 223 tested animals (29.6%). The overall objective of the study is to deepen the understanding of virus circulation in the wildlife of Southern Italy, using the wild boar as an additional sentinel species for epidemiological surveillance activities. The distinctive feature of the project lies in its multi-pathogen approach applied to a reference population distributed across a particularly wide geographical area, allowing for the simultaneous assessment of the circulation of different viruses over a large territory.