To explore changes in the epidemiological characteristics of mycoplasma pneumoniae (MP) and common acute respiratorytract infection (ARTI) virus spectrum in children before and after the coronavirus disease 2019 (COVID-19) epidemic, to provide laboratory data support for formulating the prevention strategy of ARTI in children.

A retrospective research was carried out on children with ARTI admitted to the First Affiliated Hospital of Guangzhou Medical University during 2017 to 2022.

A total of 15 485 children were enrolled in the study. The group <1 year old was defined as the infant group (3213, 20.8%). The group between 1 to 5 years old was defined as the preschool group (9186, 59.3%). The group between 6 to 14 years old was defined as the school-age group (3086, 19.9%). The positive rate of adenovirus (ADV), influenza B virus (IVB) and MP decreased significantly after COVID-19 epidemic (P<0.05). The virus with the highest positive rate before the epidemic was ADV (18.5%), followed by MP (16.1%) and influenza A virus (IVA) (15.3%), and there was no statistically significant difference in pairwise comparison between the three (all P>0.05). The virus with the highest positive rate after the epidemic is IVA (16.1%), followed by respiratory syncytial virus (RSV) (12.9%), and the difference between the two is not statistically significant (P>0.05). Except for the gender difference in the positivity rate of MP (the positivity rate of female patients was higher than that of male patients, P<0.05), there was no gender difference in the positivity rate of other viruses. By age group, the highest positive rate of ADV before the epidemic was in the preschool age group (21.6%), followed by the school-age group (13.6%), with a statistically significant difference (P<0.05). However, there was no statistically significant difference in positive rates between the preschool age group (6.7%) and the school-age group (3.9%) after the epidemic (P>0.05). The positive rate was the highest in the infant group of RSV both before (21.0%) and after (24.3%) the epidemic. The positive rate was the highest in the school-age group of IVA both before (23.0%) and after (30.5%) the epidemic. The positive rate was the highest in the school-age group of IVB before the epidemic (8.4%, P<0.05), but no significant difference between three groups after the epidemic (P>0.05). The positive rate was the highest in the school-age group of MP both before (32.4%) and after (7.3%) the epidemic (P<0.05). Before the COVID-19 epidemic, ADV and IVB were prevalent in spring and summer, and sporadic after the epidemic, with no obvious epidemic seasons. IVA was prevalent in winter before the epidemic, there was also summer epidemic characteristic now.

ARTI is common seen in school-age children after the epidemic. RSV is most common detected in infancy, and girls are susceptible to MP. The positive rates of ADV, IVB and MP decreased significantly after the COVID-19 epidemic. ADV and IVB showed sporadic status after the epidemic without obvious epidemic season, while IVA showed multi-season epidemic characteristics.