Clinical analysis of Mycoplasma pneumoniae pneumonia combined with adenovirus infection in children with lobar pneumonia.

Objective: Mycoplasma pneumoniae (MP) is a major pathogen that causes community-acquired pneumonia in children with a high rate of co-infection. Human adenovirus (HAdV) is a common co-infecting pathogen. This study aimed to analyze the clinical characteristics of children with lobar pneumonia caused by co-infection with MP and HAdV, and to investigate the correlation between the MP mutation sequence ratio (mutation depth/MP count) and HAdV sequence count with disease severity, thus providing evidence for clinical diagnosis and treatment.

Methods: Children with MP-infected lobar pneumonia hospitalized in the Department of Pediatric Respiratory Medicine at the First Hospital of Jilin University from September to November 2023 were enrolled in this study and divided into MP and MP + HAdV groups. Clinical manifestations, laboratory examinations, and treatments were compared between the two groups. Correlations of the MP mutation sequence ratio and HAdV sequence count with clinical manifestations, laboratory examinations, and treatments were analyzed.

Results: A total of 154 children with MP lobar pneumonia were included, with 96 cases in the MP group and 58 cases in the MP + HAdV group. The results showed that the MP + HAdV group had a longer total disease duration, fever duration, intravenous anti-MP drug administration duration, and systemic corticosteroid application duration, with a higher proportion of intravenous immunoglobulin use. The MP group had higher CRP levels and a higher incidence of pulmonary necrosis. After 10 days of treatment, the MP group showed better improvement in the pneumonia volume than the MP + HAdV group. There were no significant differences between the two groups in the length of hospital stay, peak fever, wheezing and rash, oxygen therapy proportion, or second-line anti-MP drug usage. No significant differences were observed between the two groups in the WBC, ESR, LDH, D-dimer, albumin, ALT, ferritin levels, incidence of atelectasis, pleural effusion, or bronchoscopy findings.

Conclusion: Co-infection with HAdV can exacerbate the condition of children with MP lobar pneumonia and increase treatment difficulty. Higher MP mutation sequence ratios are associated with more severe airway mucosal damage, and higher HAdV viral loads correlate with more severe disease.