Investigation and analysis of a cluster outbreak of Mycoplasma pneumoniae infection in a school
10.19428/j.cnki.sjpm.2024.23855
- VernacularTitle:一起学校肺炎支原体感染聚集性疫情的调查分析
- Author:
Ling XU
1
;
Jiayi SUN
1
Author Information
1. Department of Infectious Diseases Prevention and Cure， Shangcheng District Center for Disease Control and Prevention， Hangzhou， Zhejiang 310004， China
- Publication Type:Journal Article
- Keywords:
Mycoplasma pneumoniae;
outbreak;
school
- From:
Shanghai Journal of Preventive Medicine
2024;36(8):741-745
- CountryChina
- Language:Chinese
-
Abstract:
ObjectiveTo investigate a cluster outbreak of Mycoplasma pneumoniae （MP） infection in a school in Shangcheng District， Hangzhou， and to provide references for the prevention and control of similar epidemics in the future. MethodsCases were defined and searched， and telephone follow-ups were conducted one by one for the searched cases. A questionnaire on the factors related to MP infection was designed to collect information， and the questionnaire was filled under the guidance of professionals from the centers for disease control and prevention （CDC）. Throat swab samples from cases and their close contacts were collected for the detection of influenza virus， adenovirus and MP nucleic acids. ResultsA total of 28 cases were found in this outbreak， all of them were students from the same class， and the incidence rate of the students in the class was 68.29%， with an incidence rate of 66.67% （12/18） in male students and 69.57% （16/23） in female students. The main clinical manifestations were cough （26 cases， 92.86%） and fever （21 cases， 75.00%）， with a median fever day of 5 days. A total of 20 cases （71.43%） had pneumonia， 13 cases （46.43%） were hospitalized， with a median hospitalization day of 5 days. There were no severe and fatal cases. The epidemic lasted for 42 days， and the cases were mainly concentrated between November 6 and November 20， with a total of 22 cases （78.57%）. The investigation of infection factors showed that wearing a mask in public places with dense population out of school was a protective factor for MP infection （OR=0.27， 95%CI： 0.08‒0.94， P=0.040）， and picky eating was a risk factor for MP infection （OR=8.60， 95%CI： 1.30‒56.75， P=0.036）. Based on the comprehensive epidemiological history， clinical symptoms， and laboratory results of the cases， it is determined that the epidemic is a clustered outbreak of MP infection， with a high possibility of intra-class transmission caused by the first case of hospital infection. ConclusionThe incubation period of MP infection is long， the infectivity is strong， the illness is prolonged， and the mild hidden infection rate are relatively high. It is suggested that the inclusion criteria for suspected cases should be lowered to improve the sensitivity of surveillance during the epidemic management. Class suspension criteria should be made based on the length of the incubation period and the extent of the outbreak， and which should be at least longer than the average incubation period （2 weeks）.
