Abstract

abstract: “Early detection of African swine fever (ASF) is crucial for preventing widespread epidemics, especially during the initial phase of an outbreak when disease prevalence is low, animals may be asymptomatic, or clinical signs are masked by co-circulating diseases. This study systematically evaluated four sampling strategies for detecting ASFV-infected animals in suspected growing pig farms within the first 14 days of the introduction of either a high- or moderate-virulence ASFV strain. The sampling strategies included random sampling, targeted sampling of pens with clinical animals, and informational sampling based on estimated pen infection probabilities. These methods considered different pig and pen sample sizes across 1,865 commercial swine farms in 33 U.S. states and the presence of PRRSV as a co-circulating disease. The results indicated that sampling 30 pens with one pig per pen using the targeted and random pen selection method yielded the highest detection sensitivity, even with co-circulating diseases interfering with accurate clinical ASF case identification. Conversely, sampling only 5 pens resulted in the lowest sensitivity. These findings offer valuable insights for enhancing ASF surveillance strategies in the U.S. and can inform preparedness efforts for other foreign animal diseases.”