Abstract: Objective To analyze the infection situation of 7 common viruses [parainfluenza virus Ⅰ(PIVⅠ),parainfluenza virus Ⅱ(PIVⅡ),parainfluenza virus Ⅲ(PIVⅢ),respiratory syncytial virus (RSV),influenza virus A (IVA),influenza virus B (IVB) and adenovirus (ADV)] among children with acute lower respiratory tract infection. Methods Nasopharyngeal secretion was collected from 2 425 hospitalized children with acute respiratory tract infection,and 7 respiratory viruses were detected to analyze the clinical epidemiological characteristics by age group [1 526 cases of infants(≤3 years old),650 cases of preschools(4-7 years old) and 250 cases of children(≥8 years old)],virus distribution and seasons. Results Among 2 425 children,552 cases were shown to be positive for 7 viruses which included 360 cases of single virus infection (65.22%) and 192 cases of mixed infection(34.78%). The total positive rate was 22.76%. In different age groups,the number of infected infants were 377 cases (68.29%),including 242 cases of single virus infection (43.84%) and 135 cases of mixed infection (24.46%). Among the 7 viruses, the infections were mainly related to PIVⅢ infection with 196 cases (35.51%),followed by RSV infection [183 cases (33.15%)]. In 4 seasons, the positive rates were 17.79%(spring),19.73%(summer),22.37%(autumn) and 31.01%(winter), respectively. The positive rate in winter was the highest. Conclusions PIVⅢ is the major virus in children with respiratory tract infection. The respiratory tract viral infection rate in infants (≤3 years old) is the highest. The respiratory viruses are most prevalent in winter.

Key words: Parainfluenza virus, Respiratory syncytial virus, Influenza virus, Adenovirus, Respiratory tract infection, Child