Canadian Food Inspection Agency, Ottawa, ON, Canada.
Transbound Emerg Dis. 2011 Feb;58(1):1-30. doi: 10.1111/j.1865-1682.2010.01173.x. Epub 2010 Oct 12.
Bovine anaplasmosis, caused by Anaplasma marginale, is an infectious but non-contagious disease. It is spread through tick bites or by the mechanical transfer of fresh blood from infected to susceptible cattle from biting flies or by blood-contaminated fomites including needles, ear tagging, dehorning and castration equipment. Transplacental transmission of A. marginale may contribute to the epidemiology of bovine anaplasmosis in some regions. Bovine anaplasmosis occurs in tropical and subtropical regions worldwide. Cattle of all ages are susceptible to infection with A. marginale, but the severity of disease increases with age. Once cattle of any age become infected with A. marginale, they remain persistently infected carriers for life. Diagnosis of bovine anaplasmosis can be made by demonstration of A. marginale on stained blood smears from clinically infected animals during the acute phase of the disease, but it is not reliable for detecting infection in pre-symptomatic or carrier animals. In these instances, the infection is generally diagnosed by serologic demonstration of antibodies with confirmation by molecular detection methods. The susceptibility of wild ruminants to infection by A. marginale and the role of wild ruminants in the epidemiology of bovine anaplasmosis are incompletely known owing to lack of published research, lack of validation of diagnostic tests for these species and cross-reaction of Anaplasma spp. antibodies in serologic tests. Control measures for bovine anaplasmosis vary with geographical location and include maintenance of Anaplasma-free herds, vector control, administration of antibiotics and vaccination.
牛无浆体病由边缘无浆体引起，是一种传染性但非接触性疾病。它通过蜱叮咬或机械传播，将受感染牛的新鲜血液从吸血蝇或受血液污染的媒介物（包括针、耳标、去角和阉割设备）转移到易感牛身上而传播。边缘无浆体的经胎盘传播可能导致某些地区牛无浆体病的流行病学发生。牛无浆体病发生在全球的热带和亚热带地区。所有年龄段的牛都易感染边缘无浆体，但随着年龄的增长，疾病的严重程度会增加。一旦任何年龄段的牛感染了边缘无浆体，它们将终身成为持续感染的携带者。通过在疾病的急性阶段从临床感染动物的染色血涂片上显示出边缘无浆体，可以诊断牛无浆体病，但在无症状或携带者动物中检测感染时并不可靠。在这些情况下，通常通过血清学检测抗体并通过分子检测方法进行确认来诊断感染。由于缺乏已发表的研究、缺乏针对这些物种的诊断测试的验证以及在血清学测试中无浆体属抗体的交叉反应，野生反刍动物对边缘无浆体的易感性以及野生反刍动物在牛无浆体病流行病学中的作用尚不完全清楚。牛无浆体病的控制措施因地理位置而异，包括维持无浆体牛群、控制媒介物、使用抗生素和接种疫苗。
