河南省信阳地区鼠类感染立克次体的调查

Surveillance on Rickettsia in epidemic areas of scrub typhus in Xinyang areas of Henan province

目的了解河南省信阳疫区鼠类中恙虫病东方体、斑点热及斑疹伤寒立克次体感染状况。方法采用巢式一聚合酶链反应（nested—PCR），对信阳市淮滨县捕获的家鼠肝、脾、肾、血液标本进行扩增恙虫病东方体、斑点热群及斑疹伤寒群立克次体热休克蛋白（groEL）基因并测序分析。采用间接免疫荧光方法（IFA）对家鼠血清标本进行斑疹伤寒病原体、恙虫病东方体特异抗体检测。结果共捕获鼠62只，其中内脏标本中检出恙虫病东方体10份（16．13％），斑疹伤寒立克次体5份（8．06％），斑点热群立克次体4份（6．45％）；血液标本中检出恙虫病东方体5份（8．06％），斑疹伤寒群立克次体4份（6．45％），斑点热群立克次体1份（1．61％）。有5份标本同时检出恙虫病和斑疹伤寒，复合感染率为8．06％。在鼠内脏标本中检测到2株蚤传斑点热病原体R．felis。用IFA检测26份鼠血清抗体，3份恙虫病阳性（11．5％）。结论信阳地区啮齿动物宿主鼠类标本中检测出恙虫病东方体、斑点热群和斑疹伤寒群立克次体，存在复合带菌状况，鼠血清恙虫病东方体特异抗体流行率较高。

Objective To understand the epidemic status of Rickettsia in Xinyang areas of Henan province. Methods Samples including liver, spleen, kidney from mouse and chigger mites from Xinyang areas and serum samples were detected by nested-polymerase chain reaction （PCR） and indirect immunofluorescence assay（IFA）. Results In 62 viscus samples from mice organs, the positive rates were 16.13 %, 8.06 % and 6 ： 45 % for Orientia tsutsugamushi, R. typhii and Spotted fever group rickettsiae respectively. In blood clots samples from mice, the positive rates were 8.06 %, 6.45% and 1.61% for O. tsutsugamushi, R. typhii and Spotted fever group rickettsiae respectively. Three out of 26 mouse serum samples were positive for the predicted fluorexcent intensity O. tsutsugamushi. Conclusion Using nested-PCR and IFA methods, O. tsutsugamushi, R. typhii and Spotted fever group rickettsiae were detected in the captured mice living in Xinyang areas of Henan province. Results showed that there were intensive natural reserviors of Rickettsia in Henan province, suggesting that the risk of outbreak of Rickettsia in these areas was high.