Nga Bui Thi To, Auer Agathe, Padungtod Pawin, Dietze Klaas, Globig Anja, Rozstalnyy Andriy, Hai Tran Minh, Depner Klaus
Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi 100000, Vietnam.
Food and Agriculture Organization of the United Nations (FAO), 00153 Rome, Italy.
Pathogens. 2024 Jul 6;13(7):567. doi: 10.3390/pathogens13070567.
Selective culling, also known as the "tooth extraction approach", is a strategy for controlling African swine fever (ASF) by removing only sick and suspect animals instead of the entire herd in Vietnam. This method prioritizes preserving healthy animals, particularly valuable breeding pigs. Despite its implementation in various forms, no standardized protocol based on scientific principles has been established. Farms typically adapt this strategy based on their understanding, which can vary significantly. In implementing of selective culling that is not based on scientific principles, there is a significant risk of spreading the disease. The aim of this study is to evaluate the consequences of selective culling as currently implemented in Vietnam. Our analysis on a large sow farm revealed that current practices rely heavily on clinical observations without laboratory confirmations. This approach allows ASF-infected animals to remain on the farm longer, potentially exacerbating the spread of the virus. Thus, selective culling poses a substantial risk by potentially exacerbating the spread of disease. Our findings emphasize that early diagnosis of ASF and systematic removal of infected pigs are critical components for the effective implementation of selective culling strategies and that a high level of fragmentation to minimize contact between animals plays a key role. The optimal approach is to test conspicuous animals and separate them. Under no circumstances should suspect animals be left in the herd for several days before they become severely ill and succumb to the disease.
选择性扑杀，也被称为“拔牙式方法”，是越南通过仅扑杀患病和疑似动物而非整个猪群来控制非洲猪瘟（ASF）的一种策略。该方法优先保护健康动物，特别是有价值的种猪。尽管它以各种形式实施，但尚未建立基于科学原则的标准化方案。养殖场通常根据自身理解来调整这一策略，而这种理解可能差异很大。在实施并非基于科学原则的选择性扑杀时，存在疾病传播的重大风险。本研究的目的是评估越南目前实施的选择性扑杀的后果。我们对一个大型母猪养殖场的分析表明，当前做法严重依赖临床观察而无实验室确诊。这种方法使感染ASF的动物在养殖场停留更长时间，可能加剧病毒传播。因此，选择性扑杀可能因加剧疾病传播而带来重大风险。我们的研究结果强调，ASF的早期诊断和对感染猪的系统扑杀是有效实施选择性扑杀策略的关键组成部分，高度分散以尽量减少动物之间的接触起着关键作用。最佳方法是对明显患病的动物进行检测并将其隔离。在任何情况下，都不应将疑似动物留在猪群中数天，直到它们病情严重并死亡。
