Xiaoyuan Jing, Kun Jiang, Huiwen Tang
Following the COVID-19 pandemic, the overall incidence of CPP among children in Shanghai remained at a relatively low level, but it exhibited a clear annual increasing trend with the highest prevalence occurred in spring and school-aged children that aged 12-14 years were particularly susceptible. The majority of symptoms were fever and cough. CPP is also prone to concurrent infections with other pathogens, and a higher proportion of severe cases were observed. In children with CPP, N% >57.45%, C4 >0.28 g/L, IgE >102.40 IU/mL, and the imaging changes predominantly manifested as pulmonary consolidation may be the critical condition alerts of SCPP.
BACKGROUND: Chlamydia pneumoniae pneumonia (CPP) is a common respiratory disease in children after the coronavirus disease 2019 (COVID-19) pandemic. Some may develop severe complications and augment the health burden on children. This study aims to analyze the epidemiological and clinical characteristics of children with CPP and explored the associated factors for severe Chlamydia pneumoniae pneumonia (SCPP).
METHODS: Based on the diagnostic criteria of severe community-acquired pneumonia (CAP) defined by the 2024 revised Guidelines for the management of CAP in children, we consecutively enrolled hospitalized children with CPP from January 2022 to December 2025. We retrospectively collected the clinical data of 121 children diagnosed with CPP and divided them into severe and non-severe groups. Univariate analysis was performed to explore the potentially relevant indicators associated with SCPP occurrence. Subsequently, meaningful indicators were subjected to multivariate logistic regression analysis to screen for independent clinical correlates for SCPP.
RESULTS: A total of 6,137 hospitalized children were enrolled in this study, among whom 121 cases were diagnosed with CPP, with a total positive rate of 1.97%. The proportion of CPP among the total hospitalized showed a significant annual increasing trend (rising from 1.53% to 6.81%). The significant difference was observed among different seasons (χ2=3.516, P=0.06). Comparisons between different genders showed no statistical difference. The mean age of CPP children was 9.67±3.32 years, with the highest incidence observed in 12-14 years (positive rate:14.23%). The main clinical manifestations were paroxysmal cough and fever. Besides, pulmonary and extrapulmonary complications occurred in 32 cases (26.45%) and 13 cases (10.74%) respectively; and 79 samples were found positive detection of other pathogens. Multivariate analysis indicated that neutrophil percentage (N%) [odds ratio (OR) =1.066, P=0.02], complement 4 (C4) (OR =1,251.898, P=0.03), immunoglobulin E (IgE) (OR =1.001, P=0.03), and the imaging findings predominantly characterized by consolidation (OR =31.106, P=0.03) are the independent clinical correlates for SCPP in children.
CONCLUSIONS: Following the COVID-19 pandemic, the overall incidence of CPP among children in Shanghai remained at a relatively low level, but it exhibited a clear annual increasing trend with the highest prevalence occurred in spring and school-aged children that aged 12-14 years were particularly susceptible. The majority of symptoms were fever and cough. CPP is also prone to concurrent infections with other pathogens, and a higher proportion of severe cases were observed. In children with CPP, N% >57.45%, C4 >0.28 g/L, IgE >102.40 IU/mL, and the imaging changes predominantly manifested as pulmonary consolidation may be the critical condition alerts of SCPP.