Abstract:
Objective：To analyze the pathogen characteristics among hospitalized children with acute respiratory infections(ARI) and provide the basis for early etiology diagnosis and rational use of drugs.
Methods：Total1y 1 214 cases of hospitalized ARI children from May 2014 to July 2015 were included as research subjects. Indirect immunofluorescence assay(IFA) was applied to detect serum IgM antibodies of nine kinds of common pathogens, and the above-mentioned pathogen spectrum and prevalence state were analyzed.
Results：Among 1 214 cases of ARI children, positive rate of pathogen IgM antibody was 30.5% (371 cases). Positive rate of mycoplasma pneumoniae(MP) was the highest(16.8%), followed by influenza B virus(Flu B)(5.8%) and parainfluenza virus(PIV)(2.7%).A total of 205 cases of children had  MP infection mixed with another one kind or more than one kind of infection, accounting for 55.2% of total  mixed infections. There was statistical significance on infection rate of MP between different seasons (P＜0.008 3). The number of 1 to 3-year old children with pneumonia mycoplasma and hepatitis b virus infection was higher than that of children < 1 year old and > 3 years old(P<0.017). There was statistical significance on infection rate of Flu B between different seasons(P<0.008 3).The number of 1 to 3-year old children with flu viruses infection was higher than that of children < 1 year old and > 3 years old, but there was no statistically significant difference(P>0.017).
Conclusion：The major pathogens of hospitalized ARI children in our hospital are MP, Flu B and PIV; the mixed infection of MP with other pathogens is relatively common; MP and Flu B infections mainly occur  in summer; the infection rate of MP in children between 1 and 3 years old is high.

Key words: Acute respiratory infections, Pathogen, Mixed infection, Child