1例疑似职业暴露H7N9禽流感病例的溯源调查分析

Investigation of An Case of Human Infection With Avian H7N9 Influenza in Occupational Exposure in Chengdu City

目的调查1例疑似职业暴露H7N9禽流感病例,探索其感染的暴露因素和防控策略。方法运用现场流行病学调查方法收集病例的临床和流行病学资料,采用RT-PCR方法检测病例及相关环境样本,分析病例流行病学特征及可能感染来源。结果病例中年男性,从事禽类批发零售2年,发病前10 d经营活动接触过的活禽市场检出H7N9禽流感病毒,停止活禽交易后,采买的白条鸡摊位未检出H7N9病毒。其13名密切接触者、4名共同暴露者无续发症状,患者妻子有发烧咳嗽肺炎症状,连续2次鼻咽拭子采样,均未检出H7N9病毒,排除禽流感病例。结论成都市该例职业暴露相关H7N9禽流感病例属本地感染、感染来源与活禽市场近期被H7N9禽流感病毒污染有关。活禽市场交易是人禽流感发病的风险因素,应推广"集中屠宰、冷链运输、冰鲜上市"模式。

Objective To investigate a suspected case of H7N9 avian influenza in occupational exposure and to explore the exposure factors of infection.Methods Clinical and epidemiological data of the involved case were collected by using the field epidemiological survey method.Case samples and related environmental samples were detected by RT-PCR.Epidemiological characteristics and possible sources of infection were further analyzed.Results The occupational exposure case of human infection with H7N9 was an middle-aged male.He has been engaged in poultry wholesale or retail for 2 years.He has contacted with the live poultry market 10 days before the H7N9 infection onset,and H7N9 avian influenza virus has been detected in the live poultry market.No H7N9 virus was detected at the chicken stall.The 13 close contacting and 4 co-exposed patients showed no secondary symptoms.His wife had symptoms of fever,cough and pneumonia.Two consecutive nasopharyngeal swabs were taken,but no H7N9 virus was detected,thus excluding avian influenza.Conclusion The occupational exposure case of human infection with H7N9 avian influenza was a local non-human-to-human transmitted infection in Chengdu city.The infection source may be related to the recent H7N9 virus contamination in the livepoultry wholesale markets.Live poultry market trading is a risk factor of human avian influenza.It is necessary to implement the model of“scale farming,centralized slaughtering,cold chain transportation and chilled marketing”.