2014年淮安市人感染H7N9禽流感病例流行病学调查

摘要:目的　分析淮安市2014年4例人感染H7N9禽流感病例流行病学特征，为合理防治提供流行病学依据。方法　对确诊病例进行流行病学调查，密切接触者开展医学观察，使用RT-PCR法对标本进行检测。结果　4例病例平均年龄56.8岁，无地区或家庭聚集性，均已治愈；主要表现为流感样症状，CT检查有不同程度的肺部感染；发病到使用奥司他韦、发病到确诊、确诊到治愈的平均时间分别为5 d、11 d、15.5 d；3例病例发病前直接或间接接触过活禽，28例密切接触者未出现异常症状；活禽市场环境标本中检出H7N9禽流感病毒。结论　中老年人为人感染H7N9禽流感病例的易感人群，发病与禽类暴露关系密切，及时诊断和使用特效药可有效降低病死率。

Epidemiological investigation of influenza H7N9 virus infection in humans in Huaian City in 2014

Abstract: Objective The study aimed to analyze the epidemiological characteristics of 4 cases of influenza H7N9 virus infection in humans in Huaian City in 2014, so as to provide an epidemiological reference for the rational prevention of influenza virus infections. Methods The confirmed cases were subjected to epidemiological investigation, and close contacts of the patients were medically observed. Specimens were examined by RT-PCR. Results Average age of the 4 cases was 56.8 years old. No particular regional or familial aggregation was observed. All cases have been cured. The main manifestation was flu-like symptoms with pulmonary infections of different severities under CT scans. The average times for disease onset to receiving oseltamivir treatment for disease onset to confirmed diagnosis, and for confirmed diagnosis to full recovery were 5 days, 11 days, and 15.5 days, respectively. 3 cases had direct or indirect contacts with livestock before disease onset, and no abnormal symptoms were observed in 28 cases of close contacts. Influenza H7N9 virus was detected in environmental samples of live poultry market. Conclusion The middle aged and older adults are the susceptible populations for influenza H7N9 virus infection. The disease is closely associated with exposure to livestock. Timely diagnosis and use of specific medicines can effectively reduce case fatality rate of the disease.