一起学校流感合并肺炎支原体感染暴发调查

An outbreak of school influenza complicated with mycoplasma pneumoniae infection

目的 对上海市某学校一起聚集性发热疫情进行流行病学调查,为探索针对性预防控制措施提供参考。方法 采用现场流行病学方法,确定病例定义,开展病例搜索,描述三间分布,对人员和现场环境采样并进行实验室检测。结果 共搜索到16例流感样病例,均在二(9)班,其中15名为学生,1名为教师,学生罹患率为36.59%(15/41),平均年龄7.4岁,班级男生罹患率为36.84%(7/19),女生罹患率为36.36%(8/22);病例的病程在5~15 d,中位数为9 d,发病后有18.75%(3/16)带病上(授)课。16例病例鼻咽拭子标本均为乙型流感阳性,其中11例同时检测出肺炎支原体阳性,1例同时检测出冠状病毒OC43阳性。乙型流感合并肺炎支原体感染者体温、单核细胞数、病程均高于单纯乙型流感者(P值均<0.05)。该起疫情历时12 d,所有患病学生全部治愈出院,无重症和死亡病例,疫情得到有效控制。结论 该次疫情是一起乙型流感合并肺炎支原体引起的校园聚集性疫情。乙型流感合并肺炎支原体感染者症状重、病程长,提示疫情早期处置的重要性。

Objective To describe the clinical features, causal agent and transmission mode of a fever outbreak in a school in Shanghai. Methods Field epidemiological approaches including case definition development, searching for contacts, distribution of diseases description, environmental sampling and laboratory testing. Results A total of 16 influenza-like cases were included, all concentrated in the one class of grade two, including 15 students and 1 teacher. Among student cases, the incidence rate was 36.59%(15/41), the average age was 7.4 years, the incidence rate was 36.84%(7/19) for boys, 36.36%(8/22) for girls. The clinical course was 5-15 days, with the median of 9 days, and 18.75%(3/16) of the cases stayed studying while sick. The nasopharyngeal swab specimens in 16 cases all tested positive for influenza B, of which 11 tested positive for mycoplasma pneumoniae and 1 case also tested positive for coronavirus OC43. Body temperature, number of mononuclear cells, and treatment time of patients infected with Influenza B and mycoplasma pneumoniae were higher than those of patients infected with influenza B alone(P<0.05). The outbreak lasted for 12 days, all sick students were treated and discharged from hospital, with no severe cases or death, and the outbreak was effectively controlled. Conclusion This campus cluster outbreak caused by influenza B and mycoplasma pneumoniae. Patients with influenza B with mycoplasma pneumoniae have severe symptoms and a long course of illness, suggesting the importance of early management of the epidemic.