Della-Porta A J, Murray M D, Cybinski D H
Aust Vet J. 1976 Nov;52(11):496-501. doi: 10.1111/j.1751-0813.1976.tb06983.x.
At the end of the 1974 epizootic of bovine congenital arthrogryposis and hydranencephaly in south-eastern New South Wales, an Australia-wide serological survey (about 4,000 serums) was made to determine the ditribution of cattle possessing serum neutralising antibodies against Akabane virus. Eighty per cent of the serums from cattle in northern Australia (Western Australia, Northern Territory, and Queensland) were positive. A detailed study in the epizootic area in New South Wales (particularly around Bega) showed that 80 to 100% of serums from cows in herds in this area possessed neutralising antibodies. The animals possessing antibodies extended as far south as Genoa in north-eastern Victoria, and as far west as Darlington Point on the Murrumbidgee River. There were no positive herds along the Murray River, where an outbreak of the mosquito-borne disease Murray Valley encephalitis occurred in 1974. Serums tested from cows in the rest of Victoria, South Australia, south-western Western Australia, and Tasmania were negative. Arthrogrypotic calves born in Tasmania and south-western Western Australia were not associated with the presence of Akabane virus. In Papua New Guinea, serums collected from cattle at Boroka, Lae, and Goroka did not possess neutralising antibodies. The distribution of cattle possessing antibodies in Australia would fit a spread of the virus by Culicoides brevitarsis, a biting midge from which Akabane virus had been isolated on three occasions. The possibility of other vectors, as well as C. brevitarsis, was suggested by the presence of cows possessing antibodies at Alice Springs, where this biting midge has not been found. Possibly most cattle in northern Australia become infected early in life. The epizootics in New South Wales could occur when seasonal conditions allow a southerly extension of virus-infected C. brevitarsis which feed on susceptible pregnant animals. C. brevitarsis also bites sheep, and both neutralising antibodies to Akabane virus and congenitally deformed lambs have been observed in the epizootic area. An understanding of the distribtuion of Akabane virus and C. brevitarsis, a possible Australian vector for bluetongue virus, may prove useful if bluetongue should enter Australia.
1974年新南威尔士州东南部牛先天性关节弯曲和积水性无脑症 epizootic 结束时，在全澳大利亚范围内进行了一项血清学调查（约4000份血清样本），以确定拥有抗赤羽病病毒血清中和抗体的牛的分布情况。澳大利亚北部（西澳大利亚州、北领地和昆士兰州）80%的牛血清呈阳性。在新南威尔士州的 epizootic 地区（特别是贝加周围）进行的详细研究表明，该地区牛群中80%至100%的母牛血清拥有中和抗体。拥有抗体的动物向南延伸至维多利亚州东北部的热那亚，向西延伸至墨累河上的达灵顿角。1974年发生蚊媒疾病墨累河谷脑炎疫情的墨累河沿岸没有阳性牛群。从维多利亚州其他地区、南澳大利亚州、西澳大利亚州西南部和塔斯马尼亚州的母牛身上检测的血清均为阴性。在塔斯马尼亚州和西澳大利亚州西南部出生的关节弯曲小牛与赤羽病病毒的存在无关。在巴布亚新几内亚，从博罗卡、莱城和戈罗卡的牛身上采集的血清不具备中和抗体。澳大利亚拥有抗体的牛的分布情况符合由短角库蠓传播病毒的模式，短角库蠓是一种叮咬蠓虫，曾三次从中分离出赤羽病病毒。在爱丽丝泉发现有抗体的母牛，而该地未发现这种叮咬蠓虫，这表明除短角库蠓外还存在其他传播媒介的可能性。澳大利亚北部的大多数牛可能在幼年时就受到感染。当季节性条件允许受病毒感染的短角库蠓向南扩展并叮咬易感怀孕动物时，新南威尔士州就可能发生 epizootics。短角库蠓也叮咬绵羊，在 epizootic 地区已观察到针对赤羽病病毒的中和抗体以及先天性畸形羔羊。如果蓝舌病进入澳大利亚，了解赤羽病病毒和短角库蠓（蓝舌病病毒在澳大利亚可能的传播媒介）的分布情况可能会有帮助。
