Epidemiological and Genetic Characteristics of Mycoplasma pneumoniae Pneumonia after the Outbreak of COVID-19

Objective Mycoplasma pneumoniae pneumonia (MPP) accounts for a major part of community-acquired pneumonia in children, and we performed this study to investigate the epidemiological and genetic characteristics of MPP after the outbreak of COVID-19.Methods A total of 15,538 throat swab samples were collected from inpatients with respiratory tract infections from January 2021 to December 2021. All specimens were detected by real-time reverse transcriptase polymerase chain reaction (RT-PCR). The P1 gene of Mycoplasma pneumoniae (MP) in positive samples was amplified and sequenced.Results From January 2021 to December 2021, a total of 15,538 children with acute respiratory tract infection were tested by real-time RT-PCR in our study, including 9,056 boys and 6,482 girls. Overall, 469 (3.0%, 469/15,538) tested positive for MP, with 266 (2.9%, 266/9,056) males and 203 (3.1%, 203/6,482) females ( p = 0.48). The positive rates of MP infection in < 1 year old, 1 to 3 years old, 3 to 5 years old, 5 to 7 years old, and >7 years old groups were 1.31% (85/6,474), 1.87% (64/3,423), 3.65% (95/2,601), 8.02% (127/1,583), and 6.72% (98/1,458), respectively. The homology analysis of the P1 gene of 24 MP positive samples showed that the nucleotide sequence consistency was up to 91.2 to 99.3%.Conclusion After the outbreak of COVID-19, positive detection rate was the highest from 5 to 7 years old among children with MPP, and the genotype of MP in Hangzhou, China area was focused on P1 subtype, type I.