Department of Epidemiology, Crisis Organisation and Diagnostics, Central Veterinary Institute of Wageningen UR, Lelystad, The Netherlands.
PLoS One. 2011;6(8):e23066. doi: 10.1371/journal.pone.0023066. Epub 2011 Aug 5.
African horse sickness (AHS) is an equine viral disease that is spread by Culicoides spp. Since the closely related disease bluetongue established itself in The Netherlands in 2006, AHS is considered a potential threat for the Dutch horse population. A vector-host model that incorporates the current knowledge of the infection biology is used to explore the effect of different parameters on whether and how the disease will spread, and to assess the effect of control measures. The time of introduction is an important determinant whether and how the disease will spread, depending on temperature and vector season. Given an introduction in the most favourable and constant circumstances, our results identify the vector-to-host ratio as the most important factor, because of its high variability over the country. Furthermore, a higher temperature accelerates the epidemic, while a higher horse density increases the extent of the epidemic. Due to the short infectious period in horses, the obvious clinical signs and the presence of non-susceptible hosts, AHS is expected to invade and spread less easily than bluetongue. Moreover, detection is presumed to be earlier, which allows control measures to be targeted towards elimination of infection sources. We argue that recommended control measures are euthanasia of infected horses with severe clinical signs and vector control in infected herds, protecting horses from midge bites in neighbouring herds, and (prioritized) vaccination of herds farther away, provided that transport regulations are strictly applied. The largest lack of knowledge is the competence and host preference of the different Culicoides species present in temperate regions.
非洲马瘟（AHS）是一种马属动物病毒病，由库蠓属（Culicoides spp.）传播。自 2006 年在荷兰流行的密切相关疾病蓝舌病以来，非洲马瘟被认为是荷兰马群的潜在威胁。采用包含感染生物学最新知识的媒介-宿主模型，研究不同参数对疾病传播的影响以及评估控制措施的效果。传入时间是决定疾病是否以及如何传播的一个重要决定因素，这取决于温度和媒介物季节。在最有利和恒定的条件下发生传入时，我们的结果确定了媒介物与宿主的比率是最重要的因素，因为它在全国范围内具有高度的可变性。此外，较高的温度会加速疫情的传播，而较高的马密度则会增加疫情的范围。由于马的传染性较短，明显的临床症状和存在不易感宿主，预计非洲马瘟的入侵和传播难度将小于蓝舌病。此外，由于假定更早地进行检测，因此可以针对消除感染源来实施控制措施。我们认为，建议的控制措施是对有严重临床症状的感染马实施安乐死，并对感染马群进行媒介物控制，保护邻近马群免受蠓叮咬，以及对更远的马群进行（优先）疫苗接种，但要严格遵守运输法规。目前最大的知识空白是温带地区存在的不同库蠓属的媒介物能力和宿主偏好。
