Risk scoring of African swine fever transmission in selected provinces of the Philippines.

Abstract

Importance: African swine fever (ASF) is a contagious transboundary swine disease that poses a significant threat to the swine industry. As an archipelago, the Philippines has a geographic advantage in reducing ASF transmission risk. However, control efforts remain challenging due to the disease's complex epidemiology, lack of effective treatment, and vaccine availability. ASF transmission risk evaluation currently includes positive cases, population density, and pork production volume, but the potential role of contaminated pork commodities remains unexplored.

Objective: Using semiquantitative risk scoring, this study estimated the probability of ASF transmission in 23 selected provinces.

Methods: The factors influencing ASF spread were identified; 10 through a literature review and the positivity for ASF virus (ASFv) of meat samples from an ongoing surveillance study. Secondary data from each sampled province were collected, and the provinces were scored across these factors and classified into one of three risk categories.

Results: Six out of 23 provinces were categorized as high-risk due to the high number of ASFv-positive meat samples, backyard pigs, and ASF occurrences. Conversely, four provinces were classified as low-risk due to consistently low scores across all indicators. The difference in the meat contamination level between low- and high-risk provinces emphasizes the importance of including this factor in the ASF spread assessment.

Conclusions and relevance: Risk estimation of ASF transmission must consider meat sample contamination. Active surveillance at local borders can monitor contamination and prevent ASFv sources from entering areas. This approach allows the government to allocate resources and prioritize higher-risk areas.