University of British Columbia, School of Population and Public Health, 2206 E Mall, Vancouver, British Columbia V6T 1Z3, Canada.
University of Glasgow, School of Medical, Veterinary, and Life Sciences, Wolfson Medical School Building, University of Glasgow, University Avenue, Glasgow, G12 8QQ, UK.
J Wildl Dis. 2023 Jul 1;59(3):465-471. doi: 10.7589/JWD-D-22-00090.
African swine fever is a viral hemorrhagic disease of pigs (Sus scrofa) caused by a double-stranded DNA virus, African swine fever virus (ASFV). With up to 100% mortality in pigs and no vaccine, the socioeconomic impacts of this disease are immense. In sub-Saharan Africa, warthogs (Phacochoerus africanus) are the original vertebrate host for the virus, which is transmitted among wild suids via the soft tick Ornithodoros moubata. In Malawi, O. moubata is thought to be widely distributed, with the potential to spread ASFV beyond its historical enzootic zone in the Central Region. We surveyed 76 domestic pig farms, 18 active warthog burrows, and three bushpigs (Potamochoerus larvatus) resting sites for O. moubata in the Central Region of Malawi, and tested the ticks for ASFV using PCR. We found a limited distribution for O. moubata: 75 ticks were discovered at a single farm in the Mchinji District. Eleven percent of these ticks were ASFV positive. This suggests that wildlife and O. moubata play a limited role in the epidemiology of ASF in Malawi; thus, other factors for disease spread, such as fomites and pig-to-pig infection, need to be considered.
非洲猪瘟是一种由双链 DNA 病毒——非洲猪瘟病毒（ASFV）引起的猪的病毒性出血性疾病。由于该病在猪中死亡率高达 100%，且无疫苗可用，因此其对社会经济的影响是巨大的。在撒哈拉以南非洲，疣猪（Phacochoerus africanus）是该病毒的原始脊椎动物宿主，该病毒通过软蜱钝缘蜱（Ornithodoros moubata）在野生猪科动物中传播。在马拉维，据认为钝缘蜱分布广泛，有可能将 ASFV 传播到其在中部地区的历史地方性流行区之外。我们在马拉维中部地区调查了 76 个家猪养殖场、18 个活跃的疣猪洞穴和 3 个丛猪（Potamochoerus larvatus）休息点的钝缘蜱，并使用 PCR 方法对这些蜱进行了 ASFV 检测。我们发现钝缘蜱的分布有限：在姆钦吉区的一个单一农场发现了 75 只蜱。其中 11%的蜱呈 ASFV 阳性。这表明野生动物和钝缘蜱在马拉维 ASF 的流行病学中发挥的作用有限；因此，需要考虑其他因素，如媒介物和猪与猪之间的感染，可能导致疾病传播。
