Chenais Erika, Ahlberg Viktor, Andersson Kristofer, Banihashem Fereshteh, Björk Lars, Cedersmyg Maria, Ernholm Linda, Frössling Jenny, Gustafsson Wiktor, Hellqvist Björnerot Lena, Hultén Cecilia, Kim Hyeyoung, Leijon Mikael, Lindström Anders, Liu Lihong, Nilsson Anders, Nöremark Maria, Olofsson Karin M, Pettersson Emelie, Rosendal Thomas, Sjölund Marie, Thurfjell Henrik, Widgren Stefan, Wikström-Lassa Emil, Zohari Siamak, Ågren Erik, Ågren Estelle, Ståhl Karl
Swedish Veterinary Agency, SVA, Uppsala 75189, Sweden.
Swedish University of Agricultural Sciences, SLU, Box, 7070, Uppsala 75007, Sweden.
Transbound Emerg Dis. 2024 Jun 26;2024:6071781. doi: 10.1155/2024/6071781. eCollection 2024.
The first case of African swine fever (ASF) was confirmed in Sweden in September 2023. This article describes the local epidemiology, including the spatiotemporal dynamics of the outbreak and some of the factors that may have contributed to its apparently successful eradication. Upon detection of the outbreak, strict control measures were put in place in a preliminarily defined infected zone. A carcass search, including geo-localisation, removal, sampling, and destruction of found carcasses, was initiated and a preliminary core area was defined based on the results. Six months after confirmation of the first case, 93 wild boar carcasses had been found in the infected zone, of which 62 tested positive for ASF virus (ASFV). All ASFV-positive carcasses were found inside the core area. Based on two taphonomy methods, it was assumed that the infection was introduced between early May and late June 2023. The data also indicated that the epidemic curve peaked between mid-August and mid-September, with the last death occurring in late September 2023. Based on the average estimated time of death, geo-localisation of carcasses and two-dimensional kernel density estimation, clustering in space and time was identified. An online questionnaire with questions about hunting and the wild boar population was sent to all leaders of hunting groups in the infected zone. The results showed that the wild boar population had increased in the last 10 years but with large variations and geographical heterogeneity in space use. Disease introduction through natural wild boar movements was excluded and it was assumed that the long-distance translocation of the virus had occurred through human activities. A municipal waste collection centre without wild boar-proof fencing is located close to the epicentre of the outbreak, attracting many wild boar and contributing to the spread of the virus once it had been introduced to the population.
2023年9月，瑞典确诊首例非洲猪瘟（ASF）病例。本文描述了当地的流行病学情况，包括疫情的时空动态以及一些可能促成其成功根除的因素。疫情一经发现，就在初步划定的感染区实施了严格的控制措施。开展了尸体搜寻工作，包括地理定位、清除、采样以及销毁发现的尸体，并根据结果划定了初步的核心区域。在首例病例确诊六个月后，在感染区内发现了93具野猪尸体，其中62具经检测非洲猪瘟病毒（ASFV）呈阳性。所有ASFV呈阳性的尸体均在核心区域内被发现。基于两种尸体变化规律研究方法，推测感染是在2023年5月初至6月底之间传入的。数据还表明，疫情曲线在8月中旬至9月中旬达到峰值，最后一例死亡发生在2023年9月底。根据平均估计死亡时间、尸体的地理定位以及二维核密度估计，确定了疫情在空间和时间上的聚集情况。向感染区内所有狩猎团体的负责人发送了一份关于狩猎和野猪种群情况的在线调查问卷。结果显示，过去10年野猪数量有所增加，但空间利用存在很大差异和地理异质性。排除了通过野猪自然活动引入疾病的可能性，并推测病毒是通过人类活动进行远距离传播的。一个没有防野猪围栏的市政垃圾收集中心位于疫情爆发中心附近，吸引了许多野猪，一旦病毒传入野猪种群，就会导致病毒传播。
