Clinical values of non-bacterial pathogen IgM antibodies detection in children with respiratory tract infections

Objective To investigate the infection of non-bacterial pathogens in children with acute respiratory tract infections below 14 years old in the author's hospital. Methods In the First People's Hospital of Hefei, a total of 724 serum samples of respiratory tract infections were enrolled during the period from January to December in 2018. The 724 cases were divided into baby group(339 cases, 0-1 years old), infant group(188 cases,1-3 years old), preschool group(131 cases,3-6 years old) and school group(66 cases, 6-14 years old).The IgM antibodies of legionella pneumophila(LP), mycoplasma pneumonise(MP), coxiella burnetii(COX), chlamydia pneumoniae(CP), adenovirus(ADV), respiratory syncytial virus(RSV), influenza a virus(INFA), influenza b virus(INFB) and parainfluenza virus(PIVs) in the serum were detected by using indirect immunofluorescence assay(IFA) and a retrospective clinical analysis was performed with those positive cases. Results The results showed that the total positive rate was 37.71%(273/724) and the five detected pathogens were MP(29.70%), INFB(5.80%), RSV(4.56%), ADV(0.55%) and PIVs(0.14%), respectively. Mixed-infections of pathogens were detected in 22 cases, accounting for 8.06%(22/273) of positive cases. The total positive rates of IgM were no significant different between male and female groups(P=0.059). However, the positive rate of MP IgM antibodies were statistically significant between the two gender groups(P=0.001). The total positive rates of babies, infants, preschool and school groups were 27.14%, 53.19%, 54.20% and 48.48%, respectively. Among the four age groups, there were significant differences in the detection rates of MP,RSV and INFB(all P<0.05). MP occurred frequently in winter(50.00%, 102/204), while the prevalence of INFB was in spring. Conclusion MP is the primary non-bacterial respiratory infection occurred in hospitalized children in the First People's Hospital of Hefei. Besides, the pathogen infections of MP, RSV and INFB have characteristics of age and seasonal distribution.