2006年皖南地区一起人传粒细胞无形体病疫情的流行病学调查和处理

The epidemiological investigation and treatment to the epidemic situation of human granulocytic anaplasmosis in the southeast of Anhui in 2006

目的揭示首起人传粒细胞无形体病疫情的传染源、传播途径和调查处理过程。方法搜集疫情波及的全部病例的临床资料和实验室资料，采用个案调查和描述性流行病学方法分析感染的危险因素和流行病学特征。结果全部病例具有高热、WBC和PLT进行性下降等粒细胞无形体病典型临床特点，实验室检验结果也证实续发病例为粒细胞无形体感染。首例病人潜伏期12d，续发病例潜伏期4～13d，中位数为7d。与首例病人病后有过密切接触人员感染率14.3％。与病人在危重时有过密切接触者罹患率为23．1％。结论这是一起嗜粒细胞无形体感染引起的疫情。首例病人由蜱叮咬感染，在该病人病重住院治疗期间，由于没有采取必要的隔离防护措施，导致与其密切接触者9人发生感染发病。该病病人在危重时能将体内病原体传播给密切接触者，在诊疗过程中应加强隔离和防护。

Objective To study the source of infection, the route of transmission and the investigation treating processes of human granulocytic anaplasmosis. Methods The clinical data and the laboratory data of all cases were collected in this epidemic situation, the case survey and the descriptive study method were used to analyze the risk factor and the epidemiological characteristic of disease. Results Human granulocytic anaplasmosis has the typical clinical characteristics, such as hyperpyrexia, continuously descending WBC or PLT, the laboratory examination results confirmed that the secondary patients were infected by Anaplasma phagocytophilum. The firstpatient＇s the incubation period was 12 days, the incubation period of the secondary cases was 4-13 days, the median of the incubation period was 7 days. The infection rate about those persons who had closely contacted with the first patient was 14.3%.The results showed the attack rate was 23.1% among the persons who had the close contact with the first case in its sever period. Conclusions The kind of disease is caused by Anaplasma phagocytophilum. The first patient was infected after he was bitted by the ticks. When he was in hospital,9 people were infected because the hospital has not taken the effectually protective measures. Other people can be infected if he or she contacted these critical patients, so the protection and isolation should be taken in diagnosing or treating these patients.