湖州市某小学一起人偏肺病毒呼吸道感染暴发疫情调查

  目的  了解湖州市某小学一起人偏肺病毒(human metapneumovirus，hMPV)引起呼吸道感染暴发疫情的流行病学特征，为今后预防控制hMPV引起的上呼吸道感染学校暴发疫情提供科学参考。  方法  根据《流感样病例暴发疫情处置指南》(2018年版)等开展调查。采集现症病例咽拭子开展新冠病毒核酸检测，如为阴性再开展流感病毒等其他常见的14种上呼吸道病毒检测。  结果  共发现53例hMPV感染病例，首发病例为2020年12月15日; 病例集中在12月21—26日; 末例病例为12月29日。历时15 h疫情结束。病例均为一年级学生，发病班级罹患率为44.92%(53/118)，其中101班的罹患率为23.08%(9/39)，102班为53.85%(21/39)，103班57.50%(23/40)，差异有统计学意义(χ2=10.07，P < 0.05)。病例年龄在6~7岁。发病班级男生罹患率为48.00%(24/50)，女生为42.65% (29/68)，差异无统计学意义(χ2=0.33，P>0.05)。所有病例临床症状均较轻，以咳嗽、咽痛、流鼻涕为主，仅少部分出现发热。采集20例现症病例咽拭子标本，13例hMPV核酸阳性。  结论   hMPV引起的症状相比流感较轻，不容易引起学校和家长的重视。学校应开展相关防治知识宣传，做好晨午检，杜绝带病上课。

Investigation on an outbreak of human metapneumovirus respiratory tract infection in a primary school of Huzhou City

  Objective   To understand the epidemiological characteristics of an outbreak of respiratory tract infection caused by human metapneumovirus (hMPV) in a primary school in Huzhou City, and to provide scientific reference for the prevention and control of the outbreak of upper respiratory tract infection caused by hMPV in the future.  Methods  The investigation was carried out according to the Guidelines for Handling Influenza Like Case Outbreaks (2018 version). The throat swabs were collected to carry out COVID-19 nucleic acid test. If negative, influenza virus and other common 14 upper respiratory tract virus detection would be conducted.  Results  A total of 53 cases of human metapneumovirus infection were found, the first case was found on December 15, 2020; the cases concentrated from December 21 to December 26; the last case was on December 29. It lasted 15 days and the epidemic ended. All the cases were first-year students, and the incidence rate of the affected classes was 44.92% (53/118), among which the incidence rate of 101 classes was 23.08% (9/39), 102 classes was 53.85% (21/39), 103 classes was 57.50%(23/40), the difference was statistically significant(χ2=10.07, P < 0.05). The age of the patients ranged from 6 to 7 years. The morbidity rate of boys was 48.00%(24/50) and that of girls was 42.65% (29/68), with no significant difference(χ2=0.33, P>0.05). The clinical symptoms of all cases were mild, mainly cough, sore throat, runny nose, only a small number of fever. Throat swabs of 20 patients were collected, and 13 cases were positive for human metapneumovirus nucleic acid.  Conclusion  The symptoms caused by human metapneumovirus are relatively mild, which is not easy to attract the attention of schools and parents. Schools should carry out relevant prevention and control knowledge publicity, do a good job in the morning and afternoon inspection, and put an end to classes with diseases.