Low Sensitivity of African Swine Fever Active Surveillance Efforts in Serbia : [Preprint]

Given the absence of an effective vaccine for controlling African Swine Fever (ASF), disease management relies on strategies based on early detection, culling of infected pigs, enforcing movement controls, and maintaining stringent biosecurity measures. Since ASF was first detected in Serbia in 2019, the number of outbreaks has steadily increased, peaking in 2023. Both active and passive surveillance have been employed in the domestic pig populations for early disease detection. The primary objective of this study was to evaluate the sensitivity of the active surveillance system in detecting ASF in Serbia using data collected during active surveillance in domestic pigs across 20 districts from July to December 2022. The estimated active surveillance sensitivity varied, with rates of 0.13% for farms with up to 100 pigs, 0.19% for farms housing between 100 and 500 pigs, and 0.39% for large farms with more than 500 animals. The highest sensitivity, 0.73%, was observed for farms with over 100 animals in areas where ASF was present in the domestic population. Given the suboptimal performance, alternative approaches such as clinical and syndromic surveillance, which require fewer samples and offer highly accurate and sensitive surveillance systems, should be considered for implementation.