北京市农村人群及家畜嗜吞噬无形体和查菲埃立克体感染状况调查

Investigation on Ehrlichia chaffeensis and Anaplasma phagocytophilum infection among farmersand domestic animals in rural areas of Beijing, China

目的调查北京市农村人群及家畜新发查菲埃立克体和嗜吞噬无形体感染状况。方法按地理位置选择北京市西北（延庆）、东北（密云）及东南（通州）地区3个植被率较高的旅游县（区）。按在册户籍随机以家庭为单位，调查并采集562人及90只山羊、71头牛和2只家犬血液标本，按WHO推荐间接免疫荧光方法（mIFA）检测血清IgG抗体。动物血球提取DNA扩增无形体16SrRNA基因并测序分析。结果人群查菲埃立克体和嗜吞噬无形体抗体阳性率分别为16．5％和14．0％；山羊和牛嗜吞噬无形体抗体阳性率分别为2．3％和0；2只家犬未检测到相应抗体。山羊、牛无形体16SrRNA扩增阳性率分别为48．9％和23．9％。16SrRNA序列（228bp）分析显示，3类优势流行株无明显地理分布特征。结论北京市农村人群存在查菲埃立克体和嗜吞噬无形体感染，调查地区家畜存在无形体感染。

Objective To investigate the status of Ehrlichia （E.）chaffeensis and ArLaplasma （A.） phagocytophilum infection among fanning populations and domestic animals in the rural area of Beijing, China. Methods Blood samples from 562 farmers and 163 blood samples including 90 goats, 71 ox and 2 dogs, were collected, Specificity of IgG antibodies against E. chaffeensis and A. phagocytophilum were tested by micro-indirect immunofluorescent assay （mlFA）. 16S rRNA genes of A. phagocytophilum were amplified from the domestic animal blood samples and products were sequenced and analyzed by nested PCR. Results The positive rates of E. chaffeensis and A. phagocytophilum antibody were 16.5% and 14.0% respectively for farmers. The total positive rates of A. phagocytophilum were 2.3% and 0 for both goats and oxen respectively. No antibody was found for the 2 tested dogs. The PCR positive rates were 48.9% and 23.9% for goats and oxen respectively. Three dominant varieties of A. phagocytophilum were demonstrated in goats and oxen. Conclusion The prevalence rates of E, chaffeensis and A. phagocytophilum were identified in the rural areas of Beijing.