分析北京某次暴发性腺病毒-55型（HAdV-55）所致呼吸系统感染的临床特点，以提高对腺病毒-55型呼吸系统感染的认识和诊疗水平。

诊断为急性HAdV-55呼吸道感染的48例患者于2020年1月26日至2020年2月6日由解放军总医院第八医学中心集中收治，回顾性收集和分析患者的临床资料，包括症状、体征、实验室指标[包括血常规、红细胞沉降率、C-反应蛋白（CRP）、血生化、病原体核酸检测]、治疗方法及预后等。根据CT影响是否出现变化性肺部病变将入组患者分为肺炎组（18例）和上呼吸道感染组（30例）。两组患者治疗前后呈正态分布的计量资料比较采用配对t检验，症状分布比例比较采用卡方检验或Fisher确切概率法检验。

入组48例患者平均年龄为（20.6 ± 1.8）岁，83.3%（40/48）病例是从中等以下城市或农村初次入京；58.3%（28/48）患者最高体温> 39 ℃，其中肺炎组12例，上呼吸道感染组16例（χ² = 0.823、P = 0.346）；84.6%（22/26）咯痰患者咯黄痰，其中肺炎组11例，上呼吸道感染组11例（χ² = 0.142、P = 0.706），差异均无统计学意义。去除6例治疗超过4 d的患者，初诊42例患者外周血白细胞平均计数为（9.03 ± 0.37）× 10⁹/L，而肺炎组[（9.08 ± 3.01）× 10⁹/L]和上呼吸道感染组[（9.01 ± 2.02）× 10⁹/L]差异无统计学意义（t = -0.086、P = 0.932），38.1%（16/42）患者白细胞计数> 10 × 10⁹/L；42例初诊患者CRP平均为（29.0 ± 17.2）mg/L，而肺炎组[（30.2 ± 13.7）mg/L]和上呼吸道感染组[（28.3 ± 19.0）mg/L]差异无统计学意义（t =-0.338、P = 0.737）；肺炎病灶基本位于肺外带，接近胸膜或与胸膜连接；体温恢复正常后第7天，复测的8例患者中7例HAdV核酸阳性。

人HAdV-55所致急性呼吸系统感染者的症状及血常规表现出高热、黄痰、白细胞和中性粒细胞增高及淋巴细胞计数正常等细菌性呼吸系统感染的特点；患者体温恢复正常后1周内仍可能具有传染性。

To investigate the clinical characteristics of a fulminant respiratory infection caused by human adenovirus type 55 (HAdV-55) in Beijing, and to raise the awareness and level of diagnosis and treatment of HAdV-55 respiratory infection.

Total of 48 patients diagnosed as acute HAdV-55 respiratory tract infection were treated in The 8th Medical Center of PLA General Hospital. The clinical information of patients were collected and analyzed, retrospectively, including symptoms, signs, results of laboratory examination [including blood routine, erythrocyte sedimentation rate, C-reactive protein (CRP), blood biochemistry, pathogen nucleic acid detection, etc.], treatment methods and prognosis. Patients were divided into pneumonia group (18 cases) and upper respiratory tract infection group (30 cases) according to with or without variative lung lesions on CT image. Data with normal distribution of before and after treatment of the two groups were compared with paired t test, and the proportion of symptom distribution were analyzed by chi-square test or Fisher exact probability test.

The average age of 48 patients was (20.6 ± 1.8) years old, and 83.3% (40/48) cases were initial entry to Beijing from urban or rural areas below secondary level. There were 58.3% (28/48) patients with the highest body temperature > 39℃, including 12 cases in pneumonia group and 16 cases in upper respiratory tract infection group (χ² = 0.823, P = 0.346); 84.6% (22/26) patients with sputum had yellow sputum, including 11 cases in pneumonia group and 11 cases in upper respiratory tract infection group (χ² = 0.142, P = 0.706), both without significant differences. Excepte for 6 patients treated for longer than 4 d, the average number of peripheral white blood cells in 42 patients was (9.03 ± 0.37) × 10⁹/L, there was no significant difference between pneumonia group [(9.08 ± 3.01) × 10⁹/L] and upper respiratory tract infection group [(9.01 ± 2.02) × 10⁹/L](t =-0.086, P = 0.932). Leukocyte count in 38.1% (16/42) patients were > 10 × 10⁹/L. The average CRP of 42 patients at first visit was (29.0 ± 17.2) mg/L, but there was no significant difference between pneumonia group [(30.2 ± 13.7) mg/L] and upper respiratory tract infection group [(28.3 ± 19.0)mg/L](t =-0.338, P = 0.737). The focus of pneumonia was basically located in the extrapulmonary zone, close to or connected to the pleura. Seven days after the patient’s temperature returned to normal, 7 cases were positive for HAdV nuclear acid among the 8 cases re-measured.

With high fever, yellow sputum, increased white blood cell and neutrophil count, and normal lymphocyte count, acute respiratory infection caused by HAdV-55 showed the characteristics of bacterial infection. The virus nucleic acid remains contagious within one week after the recovery of body temperature.