Epidemiological characteristics of an outbreak of mixed infections of respiratory viruses in Zhangjiakou of Heibei, in 2022

  Objective  To understand the epidemiological characteristics of an outbreak of mixed infections of human adenovirus type 55, influenza B virus, influenza A virus and parainfluenza virus type 3 in a factory in Zhangjiakou, Hebei province, in 2022, identify the risk factors and provide scientific evidence for the early warning, surveillance and control of epidemic.

  Methods  Field epidemiological survey was conducted in all the people who might be affected by the outbreak in the factory. Throat swabs were collected from them for pathogen nucleic acid screening and multi-round regular pathogen screening were conducted for dynamic etiological surveillance.

  Results  A total of 547 cases of infections of respiratory viruses were reported in this outbreak, in which laboratory test confirmed 273 cases of human adenovirus 55 infection, 225 cases of influenza B virus infection, 40 cases of parainfluenza virus type 3 infection and 9 cases of influenza A virus infection. The cases mainly occurred in young male workers and the infection rate was higher in smokers than in non-smokers. The symptoms of influenza B virus infection were most obvious with higher proportions of fever and systemic symptoms.

  Conclusion  Young workers who smoked in this factory were the main population affected by the infections of the four respiratory viruses. Attention should be paid to health education, symptom monitoring and pathogen screening in the places with mass people to control the epidemic of respiratory diseases.