Health profile of free-range wild boar (Sus scrofa) subpopulations hunted in Santa Catarina State, Brazil.

Wild boars represent a potential dissemination source of important pathogens to public and animal health, since they can host several pathogens. This study aimed to evaluate the health profile of wild boars hunted for population control in the state of Santa Catarina (SC), south of Brazil. For this study, tissue and blood samples were collected from 61 wild boars hunted from October 2017 to November 2018. All 61 serum samples were screened for antibodies by different assays, presenting the following seroprevalence: 52.4% for porcine circovirus type 2 (PCV2); 21.3% for Leptospira spp.; 19.7% for Mycoplasma hyopneumoniae; 13.1% for hepatitis E virus (HEV); and 9.8% for influenza A virus (IAV). No seroreaction was observed for Brucella spp. and classical swine fever virus (CSFV). At necropsy, the main lesions observed were evidence of pulmonary metastrongylid parasites, haemorrhagic lymph nodes and white-spotted liver. Histopathological analyses mainly showed interstitial pneumonia, bronchopneumonia and bronchi-associated lymphoid tissue (BALT) hyperplasia. There was a significant association between metastrongylid parasitism and BALT hyperplasia in lungs. Pathological findings of wild boars indicate that the assessed individuals were not exposed to notifiable diseases, such as CSFV, African swine fever virus and foot-and-mouth disease, which cause economic damage by non-tariff trade barriers. However, the detection of antibodies against PCV2 and M. hyopneumoniae, pathogens that impact commercial production, indicates the circulation of these agents, with frequency variation in wild populations. This shows the potential risk of pathogen transmission among domestic swine populations and free-living ones. The detection of antibodies against zoonotic agents such as HEV, IAV and Leptospira spp., other than characterizing the pathogens' circulation in these populations, suggests a potential risk to public health and pig farming, depending on the interactions established with the environment, humans and domestic swine.