Investigation on the distribution of virus subtypes among children with acute lower respiratory tract infection in autumn and winter in Huizhou

Objective To investigate the distribution of virus subtypes among children with acute lower respiratory tract infection in autumn and winter in Huizhou.Methods A total of 511 children with acute lower respiratory tract infection admitted to our hospital from 2016 to 2018 were enrolled. The visit time was from July to December each year. Nasopharyngeal secretions were taken and 7 common lower respiratory viruses were detected by direct immunofluorescence. They included respiratory syncytial virus,influenza A virus,influenza B virus,parainfluenza virus type 1,parainfluenza virus type 2,parainfluenza virus type 3 and adenovirus.Results The positive rate of virus detection in sputum samples of 511 children with acute lower respiratory tract infection was 30.72%(157/511). Among the subtypes,the respiratory syncytial virus accounted for the highest proportion of 69. 43%(109/157),and the parainfluenza virus type 1 accounted for the lowest of 2.55%(4/157). There was no significant difference in the rate of infection of lower respiratory tract virus and the proportion of each virus subtype(P>0.05). The proportion of respiratory viral infection in children with different age groups gradually decreased with age. The highest proportion of respiratory virus infection in children aged 29 days to <1 year old was 36.31%(57/157). Among the types of viral infections,children with respiratory syncytial virus accounted for the highest proportion. Respiratory syncytial virus infection in children aged 29 d-<1 year old was higher than that in 1-3 years old and 3 years old-<14 years old children(P<0. 05). The proportion of influenza A virus infection and influenza B virus infection in children aged 1 to 3 years old is higher than that of children aged 0 to ≤28 days and 29 days to <1 year old,the proportion of adenovirus infection was higher than that of children aged 0-≤28 d,29 d-<1 year old and 3 years old-≤6 years old. The difference was statistically significant(P<0. 05).Conclusion The pathogens of children with acute lower respiratory tract infection in Huizhou are mainly respiratory syncytial virus and Gram-negative bacteria. The distribution of virus subtype is closely related to the age of children.