Goetz T E, Holland C J, Dawson J E, Ristic M, Skibbe K, Keegan K G, Johnson P J, Schaeffer D J, Baker G J
Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana 61801.
Am J Vet Res. 1989 Nov;50(11):1936-9.
The seroprevalence and seasonal trend of antibody titers against equine monocytic ehrlichiosis (Potomac horse fever) were determined in apparently healthy horses in selected areas of Illinois in 1986. Sera from 1,367 horses (6 months to 29 years old) were evaluated for the presence of antibodies against Ehrlichia risticii with indirect immunofluorescence. The majority (88%) of the horses were Thoroughbred or Standardbred racehorses. The number of horses with antibodies against E risticii was 229/1,367 (16.75%). The titers in these horses ranged from 1:10 to 1:640. As the year progressed, the number of seropositive horses (titers greater than or equal to 1:10) and the magnitude of the titers increased significantly, both reaching a maximum in July and August, respectively (P less than 0.05). A relationship between seropositivity and gender was not detected. In the year prior to sampling, 56.8% of the seropositive horses had not been ill, whereas 0.8% had diarrhea, an episode of acute abdominal pain, or laminitis. It was concluded that a large number of horses in Illinois are exposed to E risticii, that maximal exposure occurs in July, and that the most common form of the disease in Illinois is not associated with clinical signs.
1986年，在伊利诺伊州部分地区表面健康的马匹中，测定了抗马单核细胞埃立克体病（波托马克马热）抗体滴度的血清流行率和季节性趋势。采用间接免疫荧光法，对1367匹年龄在6个月至29岁之间的马的血清进行了抗里氏埃立克体抗体检测。大多数（88%）马匹为纯种马或标准赛马。抗里氏埃立克体抗体阳性的马匹有229/1367匹（16.75%）。这些马匹的抗体滴度范围为1:10至1:640。随着时间推移，血清阳性马匹（滴度大于或等于1:10）数量和滴度水平均显著增加，分别在7月和8月达到最高值（P<0.05）。未检测到血清阳性与性别之间的关系。在采样前一年，56.8%的血清阳性马匹未患病，而0.8%有腹泻、急性腹痛发作或蹄叶炎。研究得出结论，伊利诺伊州大量马匹接触到里氏埃立克体，7月接触最为频繁，且该疾病在伊利诺伊州最常见的形式与临床症状无关。
