Analysis of Mycoplasma pneumoniae pneumonia and viral coinfection in southern Guangzhou after the COVID-19 pandemic.

BACKGROUND

Mycoplasma pneumoniae (MP) has recently become an important pathogen of respiratory infection in both children and adults. The objective of this study was to investigate the detection rate of MP and clinical features of viral coinfection in Mycoplasma pneumoniae pneumonia (MPP) after the coronavirus disease 2019 (COVID-19) pandemic in southern Guangzhou.

METHODS

We reviewed 3,094 patients with respiratory infection who visited the respiratory medicine and pediatrics department from October 2023 to January 2024. Patients underwent polymerase chain reaction (PCR) or immunoglobulin M (IgM) serology for MP, influenza virus (IFV), respiratory syncytial virus (RSV), adenovirus (ADV) and enterovirus (EV). We further compared the clinical, laboratory, and imaging findings of the MPP patients with and without viral coinfection. In order to identify the significant association with viral coinfection in MPP, multivariable logistic regression analysis was performed.

RESULTS

MP infection was identified in 746 (36.69%) children and 140 (13.20%) adults, and there were 308 (41.29%) children and 76 (54.29%) adults with MPP. Eighty-four (27.27%) children and 7 (5.0%) adults with MPP had viral coinfection. Viral coinfection including MPP-RSV (4.22%), MPP-ADV (4.22%), MPP-EV (7.14%) and MPP-IFV (11.68%) was identified in children. These patients had a higher frequency of fever, higher white blood cell, higher concentration of C-reactive protein and procalcitonin, and higher proportion of lactate dehydrogenase (LDH) at greater than 250 U/L. Imaging feature of consolidation and air bronchogram sign was observed in both MPP and viral coinfection. Multivariable analysis showed fever (adjusted odds ratio, 3.46; 95% confidence interval, 1.02-11.74; P=0.047) and elevated procalcitonin of greater than 5 ng/mL (adjusted odds ratio, 3.17; 95% confidence interval: 1.50-6.72; P=0.003) as the factors associated with the viral coinfection, suggesting that viral infections could aggravate the primary MP infection or predispose patients to secondary bacterial infection.

CONCLUSIONS

Viral coinfection in MPP was common after the COVID-19 pandemic in southern Guangzhou. Increase in procalcitonin should be considered as a possibility of viral coinfection in children with MPP. This finding suggests the need for viral test in children with elevated procalcitonin in MPP, which could help clinicians identify viral coinfection at an early stage and provide timely antiviral intervention.