Abstract:Objective To investigate respiratory pathogens and seasonal epidemic features of acuterespiratory tract infections in children so as to provide the basis for effective clinical prevention and treatment. Methods Indirect immunofluorescence assay was utilized to detect serum IgM antibodies against respiratory viruses and atypical pathogens from 3,461 children of 0 -12 years with acute respiratory tract infections in our hospital between January 2015 and December 2015. The pathogens included respiratory syncytial virus(RSV),adenovirus (ADV), Influenza A virus(FluA), Influenza B virus(FluB),Parainfluenze virus(PIV), mycoplasma pneumonia(MP), Chlamydia pneumoniae(CP), and legionella pneumophila (LP). Results Of 3,461 serum samples detected, the total IgM positive rate of respiratory tract infection pathogens was 69.17%. The most frequently detected pathogens were FluB (51.11%), FluA (36.38%), MP (25.14%) and RSV (9.04%). The detection rates of FluA, FluB and MP infections did not exhibit a pronounced seasonality and kept at a high level almost throughout the year. RSV epidemic peak appeared in winter and spring. ADV and CP had higher detection rates in spring and summer. PIV and LP kept at a low level throughout the year. While RSV incidence decreased significantly along with the age growth, the opposite was observed for infections of other pathogens. Mixed-infections of pathogens were detected in 1,627 cases with the positive rate of 47.01%. The most common pathogens in the co-infections were FluA+FluB and FluA+FluB+MP. Conclusions The total positive rate of 8 kinds of respiratory pathogens was 69.17% in Huaian in 2015, and the positive rate of FluB was the highest. The incidences of the infections caused by the respiratory pathogens varied in the seasons. With the growth of the age, the positive rate of RSV was significantly decreased, while the positive rates of other pathogens were gradually increased. FluA and FluB were the most common in mixed infections. Early detection of respiratory pathogens will be helpful for pediatricians to diagnose, treat and control respiratory tract infections.