浙江省湖州市某小学一起肺炎支原体呼吸道感染疫情调查

Investigation of an outbreak of Mycoplasma pneumoniae respiratory tract infection in a primary school in Huzhou City,Zhejiang Province

【目的】了解浙江省湖州市某小学一起肺炎支原体引起呼吸道感染暴发疫情的流行病学特征,为今后预防控制肺炎支原体引起的上呼吸道感染学校暴发疫情提供科学参考。【方法】根据呼吸道传染病暴发疫情调查相关要求,收集病例的基本信息、发病就诊经过和流行病学等信息。采集病例咽拭子标本开展新冠病毒核酸检测及甲、乙型流感病毒抗原检测;采集血清标本检测支原体总抗体。【结果】共纳入47例肺炎支原体感染相关病例,首发病例发病时间为2022年5月4日;病例集中发病时间在5月22日—5月31日;末例病例发病时间为6月21日。历时48 d疫情结束。病例均为二年级学生,发病班级罹患率为35.07%(47/134),其中206班为53.33%(24/45),207班为38.64%(17/44),211班为13.33%(6/45)。班级间罹患率差异有统计学意义(χ^(2)=16.57,P<0.05)。男生罹患率为32.39%(23/71),女生为38.10%(24/63),性别差异无统计学意义(χ^(2)=0.48,P>0.05)。临床表现以咳嗽、发热、咽痛为主,部分病例有肺炎体征。采集27例患者咽拭子和血清标本。结果咽拭子标本均为阴性,12份血清标本支原体总抗体阳性,阳性率44.44%。【结论】肺炎支原体引起的症状临床表现多样,体征不典型,进展慢,前期病例症状较轻,发病学生带病上课,学校晨检也未能及时发现并采取居家隔离控制措施是导致此次疫情发生的主要原因。学校应开展相关防治知识宣传,做好晨午检,杜绝带病上课。

[Objective]To understand the epidemiological characteristics of an outbreak of respiratory tract infections caused by Mycoplasma pneumoniae(MP)in a primary school in Huzhou City,Zhejiang Province,and to provide scientific reference for future prevention and control of school outbreaks of upper respiratory tract infections caused by M.pneumoniae.[Methods]According to the requirements for investigating respiratory infectious disease outbreaks,basic information,clinical history and epidemiological information were collected from the cases.Throat swab samples of cases for COVID-19 nucleic acid testing,influenza A and B virus antigen testing,and serum samples for detecting total antibody of mycoplasma were also collected.[Results]A total of 47 cases related to M.pneumoniae infection were identified.The first case occurred on May 4,2022,and the cases were concentrated between May 22 and May 31,2022.The last case occurred on June 21,marking a duration of 48 days for the outbreak.All cases were second-grade students,with an incidence rate of 35.07%(47/134)in the affected classes,with Class 206 at 53.330%(24/45),Class 207 at 38.64%(17/44),and Class 211 at 13.33%(6/45).There was a statistically significant difference in the incidence rates among the classes(χ^(2)=16.57,P<0.05).The incidence rate was 32.39%(23/71)for boys and 38.10%(24/63)for girls,with no statistically significant difference by gender(χ^(2)=0.48,P>0.05).The main clinical manifestations included cough,fever,and sore throat,and some cases exhibited signs of pneumonia.Pharyngeal swabs and serum samples were collected from 27 patients.The results were negative for pharynx swab samples,and positive for total mycoplasma antibody in 12 serum samples,with a positive rate of 44.44%.[Conclusion]Symptoms caused by M.pneumoniae are diverse in clinical manifestations,with atypical signs and a slow progression.Early cases tend to exhibit mild symptoms.The onset of the disease is not detected in time when students are attending classes.The school morning health checks fail to promptly detect it and trigger home isolation control measures,which all contribute to the outbreak of the epidemic.Schools should conduct relevant prevention and control campaigns,improve morning and afternoon health checks,and prevent students from attending classes while sick.