Identification of Risk Factors and Production Practices Associated with Type 2 Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) Positivity on Pig Farms in Jalisco, Mexico.

The modernization of pig farming has resulted in increasingly dense pig populations. While this accelerates production and ensures a steady pork supply, it also increases the risk of infection transmission. As an endemic and widely distributed pathogen, porcine reproductive and respiratory syndrome virus (PRRSV) type 2 can cause disease, depending on the production practices implemented. This study evaluated pig production conditions in Jalisco, Mexico, as well as how these conditions correlated with PRRSV detection. In total, 4207 serum samples obtained from 80 pig farms were subjected to analysis, and epidemiological information was collected to evaluate potential determinants of PRRSV presence. Positive samples were most frequently found in pigs up to 10 weeks of age, raised in semi-intensive, intensive, farrow-to-finish farm, and multisite systems, with relative frequency values ranging from 58.6% to 76.9%. The results revealed that various production practices, particularly related to biosecurity protocols, were associated with the presence of PRRSV on the farms evaluated.