DTU National Veterinary Institute, Technical University of Denmark, Lindholm, Kalvehave, Denmark.
DTU National Veterinary Institute, Technical University of Denmark, Kongens Lyngby, Denmark.
Transbound Emerg Dis. 2018 Aug;65(4):1024-1032. doi: 10.1111/tbed.12837. Epub 2018 Feb 19.
Since the introduction of African swine fever virus (ASFV) into the Baltic states and Poland in 2014, the disease has continued to spread within these regions. In 2017, the virus spread further west and the first cases of disease were reported in the Czech Republic and Romania, in wild boar and domestic pigs, respectively. To control further spread, knowledge of different modes of transmission, including indirect transmission via a contaminated environment, is crucial. Up until now, such an indirect mode of transmission has not been demonstrated. In this study, transmission via an environment contaminated with excretions from ASFV-infected pigs was investigated. Following euthanasia of pigs that were infected with an isolate of ASFV from Poland (POL/2015/Podlaskie/Lindholm), healthy pigs were introduced into the pens, in which the ASFV-infected pigs had been housed. Introduction was performed at 1, 3, 5 or 7 days, following euthanasia of the infected pig groups. Pigs, that were introduced into the contaminated environment after 1 day, developed clinical disease within 1 week, and both ASFV DNA and infectious virus were isolated from their blood. However, pigs introduced into the contaminated pens after 3, 5 or 7 days did not develop any signs of ASFV infection and no viral DNA was detected in blood samples obtained from these pigs within the following 3 weeks. Thus, it was shown that exposure of pigs to an environment contaminated with ASFV can result in infection. However, the time window for transmissibility of ASFV seems very limited, and, within our experimental system, there appears to be a rapid decrease in the infectivity of ASFV in the environment.
自 2014 年非洲猪瘟病毒（ASFV）传入波罗的海国家和波兰以来，该疾病一直在这些地区内传播。2017 年，病毒进一步向西传播，捷克共和国和罗马尼亚首次在野猪和家猪中报告了该病病例。为了控制进一步的传播，了解不同的传播模式，包括通过受污染的环境进行间接传播，至关重要。到目前为止，尚未证明存在这种间接传播方式。在这项研究中，研究了通过受 ASFV 感染猪排泄物污染的环境进行传播的情况。在对来自波兰（POL/2015/Podlaskie/Lindholm）的 ASFV 分离株感染的猪实施安乐死后，将健康猪引入曾饲养感染猪的畜栏。在感染猪群安乐死后 1、3、5 或 7 天进行引入。在第 1 天被引入污染环境的猪在 1 周内出现临床疾病，并且从其血液中分离出了 ASFV DNA 和传染性病毒。然而，在感染猪群安乐死后 3、5 或 7 天后被引入污染畜栏的猪没有出现任何 ASFV 感染迹象，并且在接下来的 3 周内从这些猪获得的血液样本中未检测到病毒 DNA。因此，结果表明，猪暴露于受 ASFV 污染的环境中可导致感染。然而，ASFV 的传染性似乎有非常有限的时间窗口，并且在我们的实验系统中，环境中 ASFV 的感染力似乎迅速下降。
