Holland C J, Ristic M, Cole A I, Johnson P, Baker G, Goetz T
Science. 1985 Feb 1;227(4686):522-4. doi: 10.1126/science.3880925.
Potomac horse fever, a disease characterized by fever, anorexia, leukopenia, and occasional diarrhea, is fatal in approximately 30 percent of affected animals. The seasonal occurrence of the disease (June to October) and evidence of antibodies to the rickettsia Ehrlichia sennetsu in the serum of convalescing horses suggested that a related rickettsia might be the causative agent. Such an agent was isolated in cultured blood monocytes from an experimentally infected pony. This intracytoplasmic organism was adapted to growth in primary cultures of canine blood monocytes. A healthy pony inoculated with these infected monocytes also developed the disease. The organism was reisolated from this animal which, at autopsy, had pathological manifestations typical of Potomac horse fever. Cross serologic reactions between the newly isolated agent and antisera to 15 rickettsiae revealed that it is related to certain members of the genus Ehrlichia, particularly to Ehrlichia sennetsu. Since the disease occurs in other parts of the United States as well as in the vicinity of the Potomac River, and since it has also been reported in Europe, the name equine monocytic ehrlichiosis is proposed as being more descriptive.
波托马克马热是一种以发热、厌食、白细胞减少和偶尔腹泻为特征的疾病，在大约30%的患病动物中是致命的。该疾病的季节性发生（6月至10月）以及康复马匹血清中对立克次氏体嗜肝埃里希体的抗体证据表明，一种相关的立克次氏体可能是病原体。从一只实验感染的小马的培养血液单核细胞中分离出了这样一种病原体。这种胞内生物体适应了在犬类血液单核细胞原代培养物中的生长。用这些感染的单核细胞接种的一匹健康小马也患上了这种疾病。该生物体从这只动物身上再次分离出来，在尸检时，这只动物具有波托马克马热的典型病理表现。新分离出的病原体与针对15种立克次氏体的抗血清之间的交叉血清学反应表明，它与埃里希体属的某些成员有关，特别是与嗜肝埃里希体有关。由于这种疾病在美国其他地区以及波托马克河附近都有发生，并且在欧洲也有报道，因此建议使用马单核细胞埃里希体病这个名称，因为它更具描述性。
