皖南地区2006年一起人传“粒细胞无形体病”疫情的流行病学特征

Epidemiological characteristic of epidemic situation about the human-infected granulocytic anaplasmosis in southern Anhui

目的描述人传"粒细胞无形体病"疫情的流行病学特征和临床特征。方法搜集疫情发生地的全部病例,采用描述性流行病学方法分析疫情的流行病学特征和临床特征,并与以往报道的蜱传"人粒细胞无形体病"临床特征相比较,分析感染的危险因素。结果人传"粒细胞无形体病"具有该病高热、WBC和PLT进行性下降等典型临床特点,热程1～6d。潜伏期4～13d,中位数为7d。与死亡病例(首例病人)病后有过密切接触的人员感染率为14.3%。与病人在危重时有过密切接触者发病率为23.1%。8例续发病例血标本检测到嗜粒细胞无形体16SrRNA基因,恢复期血清特异抗体IgG阳转,滴度1∶64～1∶128。结论这是迄今首次报告的人传"粒细胞无形体病"疫情,也是首次报告"粒细胞无形体病"可造成医源性感染。该病在早期病情较轻时可能没有传染性,与病人在危重时有过密切接触者被感染的可能性较大,应加强隔离和防护。

Objective To describe the epidemiological and clinical characteristics of epidemic situation about the human-infectect granuloeytic anaplasmosis. Methods The whole cases were collected which had occurred in this epidemic. Then the epiderniologieal and clinical characteristics were analyzed by descriptive epidemiology, compared with the clinical characteristic of previous tick-infected Human granulocytic anaplasmosis. At the same time, the risk factor of infection was analyzed. Results The cases had the typical clinical characteristic, such as hyperpyrexia, progressive falling of WBC and PLT. The fever process was 1-6 days, the incubation period being 4-13 days and its median 7. The infection rate of the persons who had close contact with the first case during his or her illness was 14.3 %. The attack cases among the persons who had close contact with the first case when he or she was in a critical condition were 23.1%. The blood sample from 8 secondary attack cases was tested positive about The 16S rRNA gene of granulocytic anaplasma. The specific serum antibody was seroconversion in convalescence and its titer was 1 ： 64 - 1 ： 128. Conclusions This is not only the first report about human-infected granulocytic anaplasmosis but also the first one that granulocytic anaplasmosis can result in iatrogenic infection. There is even no infectiousness in the early light situation of disease, but the possibility of infection increases if people have close contact with patients when their illness is serious. Therefore, isolation and protection have to be practiced.