Molecular detection of African swine fever virus in pork and pork products and associated risk factors in the Philippines

Abstract

African swine fever (ASF) is a contagious hemorrhagic disease affecting both domestic and wild pigs with high mortality rate and severe socio-economic losses. Due to the virus’ potential ability to remain infectious in suitable conditions and environments, it is imperative to identify risk factors that may contribute to its transmission. The Philippines' current ASF surveillance relies on pig blood samples. With this very limited epidemiological data, it is imperative to include raw meat and processed pork products due to high ASF transmission risks. In this study, a total of 384 raw pork and 384 processed pork products from selected wet markets were collected and detected the ASF virus (ASFv) VP72 gene using real-time polymerase chain reaction (rt-PCR), and the overall positivity rates were 10.16% and 10.68%, respectively. Moreover, an interview with wet market vendors was conducted, and the Least Absolute Shrinkage and Selection Operator (LASSO) regression was employed to identify possible factors associated with sample positivity. Results showed that ASFv-positive samples were linked to zoning status, rainy seasons, Longganisa preparation, selling different meat types, longer pork batches, and cleaning or disinfection in market stalls. Overall, ASFv contamination in pork and processed pork products can pose a threat to the swine industry, and market practices may further lead to ASFv persistence in these commodities which may contribute to ASF spread. Therefore, there’s a need to address this risk by strict surveillance and proper handling procedures throughout the food supply chain.