河南首起恙虫病暴发的流行病学调查

The Epidemiological Investigation on the First Outbreak of Tsutsugamushi Disease in Henan Province

目的 查清本次暴发的流行原因和流行状况。方法 采用现场流行病学调查的方法并依据血清学、免疫学以及分子生物学实验结果确认。结果 2005年河南省南部淮滨县新里镇大董庄发生一起恙虫病暴发流行，自9月26日-11月10日共发病32人，以成人为主，主要临床表现为发烧、头疼、淋巴结肿大、皮疹。恢复期病人血清外斐氏OXk1：160实验阳性率100％，最高效价达1：2560，典型病人的两次血清呈4倍升高；恙虫病荧光抗体阳性率100％，最高效价达1：2560。血清分型主要是Gilliam、Karp、Kato3个血清型；套式PCR检测病人血3份阳性。结论 本次为河南首起恙虫病暴发流行。

Objectives： To explore on the causation of the epidemic and to investigate the characteristics of the distribution. Methods： Using methods of field epidemiolagical investigation as well as serological, immunological and molecular -biological diagnosis to determine this outbreak. Results： In the year of 2005, there was an outbreak of tsutsugamushi disease in Dadong village of Xinli town of Huaibin County that is located in the southern part of Henan province. Since 26th September to 10th November 32 cases of tsutsugamushi were found. Most patients were adults. The main clinical symptoms were fever, headache, swelling of lymph gland and tetter. Weil -Felix reaction OXk was all above 1： 160, the highest titer was 1： 2560. The positive rate was 100% The results of antibodies to Rt were detected by Indirect immunofluoresent antibody techniques and the positive rate was 100%. The highest titer was 1： 2560. It was identified as Rt Gilliam, Rt. Karp and Rt. Karp with serological typing. The Rt specific DNA band were observed by nested PCR in the DNA extracted from the blood of 3 patients. Conclusion： The first outbreak of tsutsugamushi disease was discovered in Henan province.