安徽省某地一例人感染H5N1禽流感病例流行病学调查分析

Epidemiological investigation and analysis of a human case infected with H5N1 avian influenza in Anhui Province

目的 通过对安徽省某地一例人感染H5N1禽流感病例的调查分析,探索可能的感染来源以及暴露因素,为疫情防控提供科学依据.方法 采用现场流行病学调查和实验室检测相结合的方法,调查病例发病、就诊经过以及居住环境,排查密切接触者并进行医学观察,采集密切接触者及相关环境样本开展实验室检测.结果 确诊一例人感染H5N1禽流感病例,经救治于2023年3月16日出院.密切接触者均未出现发热等异常临床表现,禽流感病毒核酸检测结果均为阴性,未发现人传人证据.患者有病死禽接触史,患者家禽及其环境30份样本中经检测有7份H5阳性.结论 确诊病例的感染来源可能与其家中饲养的病死鸡有关,鉴于患者住宅离候鸟迁徙的中转地较近,不排除候鸟迁徙途中带入H5N1病毒导致患者家中饲养的鸡感染,后患者因意外暴露导致感染的可能.

Objective To analyze the investigation results of one H5N1 avian influenza infection case in Anhui province and explore possible sources and exposure factors,so as to provide scientific basis for epidemic prevention and control.Methods Field epidemiological investigation and laboratory testing were combined to investigate the history of disease onset and treatment as well as the living environment of the patient.Close contacts were screened and medical observation was carried out.Samples of close contacts and related environment were collected for laboratory testing.Results A human case of H5N1 avian influenza was confirmed and the patient was discharged from hospital on March 16,2023.None of the close contacts showed any abnormal clinical manifestations,e.g.fever and no nucleic acid test results of avian influenza virus was positive.No evidence of human-to-human transmission was observed.The patient had a history of contact with sick and dead poultry,and 7 out of 30 samples from the patient's poultry and the environment tested positive for H5.Conclusions The source of infection of the confirmed cases may be related to the dead chickens raised at home.Given that the residence of the patient is close to the transit place of migratory birds,the possibility that the H5N1 virus was brought into the chickens raised at the home of the patient during migration,and then the patient was infected due to accidental exposure,cannot be ruled out.