关键词: 恙虫病, 立克次体, 巢式聚合酶链反应, 血清型, 流行病学

Abstract: 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 Weil-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.