目的监测流感病毒临床严重性的变化,了解合肥地区人感染禽流感病毒的状况,及时发现人感染H7N9禽流感病例。方法对合肥市各级医疗机构监测到的不明原因肺炎病例进行流行病学调查,并采集上、下呼吸道标本开展流感病毒核酸检测。结果 2014年4月1日-2015年3月31日,共采集到不明原因肺炎病例标本43例,检出流感病毒核酸阳性16份,阳性率37.21%。其中B型1份(2.32%)、H3型11份(25.58%)、H7型4份(9.30%)。4名H7N9患者均为男性,在发病前一周内均有活禽接触史。确诊流感病例均主要集中于2015年春季。结论合肥地区不明原因肺炎病例中存在流感病毒感染,不明原因肺炎病例监测高峰期与流感监测一致,不明原因肺炎监测丰富了流感监测内容,为流感防控提供了科学依据。 Objective To monitor the clinical severity of influenza virus, investigate the status of human infection with avian influenza virus in Hefei and find out the human cases of H7N9 bird flu in time. Methods Epidemiological investigation of pneumonia cases of unexplained pneumonia detected by medical institutions at all levels in Hefei were conducted. Influenza virus nucleic acid was detected in upper and lower respiratory tract specimens. Results From April 1, 2014 to March 31, 2015, 43 cases of pneumonia of unknown cause were collected, of which 16 were positive for influenza virus. The positive rate was 37.21%. One type B (2.32%), H3 type 11 (25.58%), H7 type 4 (9.30%). Four H7N9 patients were both male and had live poultry contact history within the previous week. Confirmed flu cases are mainly concentrated in the spring of 2015. Conclusions Influenza virus infection exists in cases of unexplained pneumonia in Hefei. The peak period of pneumonia cases with unknown causes is consistent with that of influenza surveillance. Unknown pneumonia monitoring enriches the content of influenza surveillance and provides a scientific basis for prevention and control of influenza.