[Clinical characteristics of pediatric Mycoplasma pneumoniae necrotizing pneumonia with co-infections].

Objective: To explore the differences in clinical characteristics, laboratory indicators, and outcomes of Mycoplasma pneumoniae (MP) necrotizing pneumonia (NP) in children with co-infection of bacteria or viruses. Methods: A retrospective cohort study was conducted. Clinical data of 109 children with MPNP hospitalized in the Department of Infectious Diseases and Pediatric Intensive Care Unit of the Children's Hospital, Zhejiang University School of Medicine from January 2019 to March 2024 were included. Based on pathogen results, the children were divided into a single MP infection group, an MP co-infection with bacteria group, and an MP co-infection with viruses group. Demographic data, clinical manifestations, laboratory indicators, bronchoscopic findings, and clinical outcomes were compared among the three groups. Inter-group comparisons were performed using independent samples t-test, Kruskal-Wallis H test, Chi-square test, and Fisher's exact test. Length of hospital stay among the three groups was analyzed using Kaplan-Meier curves. Results: Among the 109 MPNP children, there were 50 males and 59 females, with an onset age of 7.1 (5.5, 8.3) years. There were 68 cases in the single MP infection group, 30 cases in the MP co-infection with viruses group, and 11 cases in the MP co-infection with bacteria group. Statistically significant differences were observed among the three groups in terms of post-admission fever duration, rate of closed drainage of thoracic cavity, and serum interleukin (IL)-6 levels (all P<0.05). Among the 65 children who underwent a second bronchoalveolar lavage, there was a statistically significant difference in the incidence of persistent mucus plugs among the three groups (42.9% (18/43) vs. 12/15 vs. 3/7, P<0.05). Conclusions: In children with MPNP co-infected with bacteria, clinicians should be aware of the possibility of longer fever duration, higher rates of thoracic drainage, and higher levels of IL-6. Co-infection with viruses is associated with a higher proportion of persistent mucus plugs, which may necessitate more aggressive bronchoscopic intervention.