Istituto Superiore per la Protezione e la Ricerca Ambientale, Via Ca' Fornacetta, 9, 40064, Ozzano Emilia, BO, Italy.
Acta Vet Scand. 2022 Jul 27;64(1):16. doi: 10.1186/s13028-022-00636-z.
African Swine Fever (ASF) is a highly lethal viral disease caused by the African Swine Fever Virus (ASFV), the only virus of the Asfaviridae family, which affects different species of wild and domestic suids, and for which no vaccination or effective medical treatment is currently available. The virus can survive for long periods in the environment, and humans can unintentionally act as vectors through infected fomites, a risk that is linked to the ASF introduction into pig farms. We ran a simulation study, in which we reconstructed the probability process leading to the different forms of human-mediated ASF contamination in ASF endemic areas. We compared the infection risks related to different types of human forest activities and produced estimates of the minimum expected number of human-induced contamination events occurring annually at the scale of some European countries.
When analysed on a short temporal scale and in a relatively small spatial context, ASF environmental contamination appeared as a rather unlikely event for most of the simulated forest uses, with contamination probabilities often lower than 0.1%. When scaling up the contamination process to a whole year and to large geographic areas, though, the accumulation of the same forest activities, repeated several times per month within the same patch of forest, produced the expectation that thousands of contamination events would occur each year, with potentially relevant epidemiological consequences. Wild boar supplemental feeding and forest logging emerged as the riskiest activities in terms of contamination probabilities, but risk was highly influenced by the frequency and intensity of the different types of forest use.
The risk of human-mediated ASF environmental contamination should not be disregarded when planning management actions to reduce ASF circulation and prevent its breach into the pig farming system. Supplemental feeding should be strongly reduced or avoided in ASF affected areas. Wild boar hunting, which is often employed as an active management tool in ASF affected areas, should be seen as both a tool for controlling wild boar density and as a potential risk for further contamination. It is essential to implement and enforce strict biosecurity measures for all forest-based human activities in ASF endemic areas.
非洲猪瘟（ASF）是一种由非洲猪瘟病毒（ASFV）引起的高致死性病毒性疾病，ASFV 是唯一的 Asfaviridae 科病毒，可感染不同种类的野生和家养猪科动物，目前尚无疫苗或有效治疗方法。该病毒在环境中可长时间存活，人类可通过受感染的媒介物无意中成为传播媒介，这与 ASF 引入养猪场有关。我们进行了一项模拟研究，重建了导致 ASF 流行地区不同形式的人为 ASF 污染的概率过程。我们比较了不同类型的人类森林活动的感染风险，并估计了一些欧洲国家每年发生的人为污染事件的最小预期数量。
在短时间尺度和相对较小的空间范围内分析时，对于大多数模拟的森林用途，ASF 环境污染似乎不太可能发生，污染概率通常低于 0.1%。然而，当将污染过程扩展到一整年和大面积地理区域时，即使在同一森林斑块内每月重复多次相同的森林活动，也会产生每年发生数千次污染事件的预期，这可能会产生相关的流行病学后果。野猪补充喂养和森林采伐成为污染概率最高的风险活动，但风险高度受不同类型森林使用的频率和强度的影响。
在规划管理行动以减少 ASF 传播并防止其突破到养猪系统时，不应忽视人为介导的 ASF 环境污染的风险。在 ASF 流行地区应强烈减少或避免补充喂养。野猪狩猎在 ASF 流行地区经常被用作主动管理工具，应被视为控制野猪密度的工具，也是进一步污染的潜在风险。在 ASF 流行地区，对于所有基于森林的人类活动，实施和执行严格的生物安全措施至关重要。
