河南省首次实验室证实恙虫病暴发疫情

The lab identification on tsutsugamushi disease for the first outbreak in Henan province

目的调查以发热、头痛、淋巴结肿大、皮疹为主要症状的不明原因疾病病因。方法对可疑病人进行流行病学调查,用血清学、巢式PCR方法检测病人血清抗体滴度、血清型及立克次体特异性基因片段。结果对发生在农村的32例病人中的20例病人进行血清外裴OXk凝集反应,阳性率达100%,其中11份的第2次病人血清OXk反应呈4倍升高;间接免疫荧光法检测IgM和IgG抗体,20份均为阳性,最高达到1∶2560;恙虫病血清学分型Gilliam 4例,Karp6例,Kato 8例。巢式PCR检测病人血凝块,结果3份扩增出Ot特异性DNA片段。结论首次证实河南省出现恙虫病暴发疫情。

Objective To explore the factors causing the mainly clinical symptoms of fever, headache, swelling of lymph gland and tetter from unknown causation in Henan province. Methods An epidemiological investigation was carried out in Huaibin county of Henan. Serological method was used to determine antibodies titer and serological type. Specific gene fragments of Orientia tsutsugamushi （Ot） were detected by nested PCR. Results 32 suspicious patients were found in the rural. Blood samples were taken from 20 of 32 cases, positive rate of those was 100% for OXk by Well-Felix reaction. And the OXk reaction titers were four times rise among 11 of 2^nd blood samples. IgM and IgG antibodies to Ot were detected by IFA as positive in all 20 cases. And the highest titer was 1 ： 2560. Of serological typing of 20 cases, 4 were identified as Gilliam, 6 as Karp and 8 as Kato. Specific DNA bands of Ot were observed by nested PCR for the DNA extraction from the blood clot of 3 patients. Conclusion Infection of tsutsugamushi disease was discovered for the first time in Henan province.