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Risk factors for severe Chlamydia pneumoniae pneumonia in children: a retrospective case-control study

Di Hu1,2, Yingqian Zhang2,3,4, Ran Ma1,2

  • 1Graduate School, Hebei Medical University, Shijiazhuang, Hebei, China.

Frontiers in Pediatrics
|June 22, 2026
PubMed

Insights

In children with Chlamydia pneumoniae pneumonia (CPP), a lower lymphocyte percentage and elevated immunoglobulin A (IgA) are linked to severe disease. These findings may aid in identifying children at higher risk for severe CPP.

Area of Science:

  • Pediatric infectious diseases
  • Respiratory medicine
  • Clinical microbiology

Background:

  • Chlamydia pneumoniae pneumonia (CPP) is a significant cause of respiratory illness in children.
  • Understanding risk factors for severe CPP is crucial for timely intervention and improved outcomes.

Purpose of the Study:

  • To investigate the clinical features of CPP in children.
  • To identify risk factors associated with the progression of CPP to severe pneumonia.

Main Methods:

  • A retrospective study of 133 children diagnosed with CPP.
  • Classification of disease severity based on established pediatric pneumonia guidelines.
  • Comparison of demographic, clinical, and laboratory data between non-severe and severe CPP groups.
  • Multivariate logistic regression to determine independent risk factors for severe CPP.

Main Results:

  • Children with severe CPP exhibited higher peak temperatures and longer fever duration compared to those with non-severe CPP.
  • Severe CPP cases showed a lower lymphocyte percentage and elevated white blood cell (WBC) count, C-reactive protein (CRP), and immunoglobulin A (IgA) levels.
  • Multivariate analysis identified decreased lymphocyte percentage (OR=0.943) and elevated IgA (OR=2.227) as significant independent risk factors for severe CPP.

Conclusions:

  • Reduced lymphocyte percentage and increased serum IgA levels are associated with severe CPP in children.
  • These biomarkers may serve as potential indicators for risk stratification in pediatric CPP cases.
  • Further multicenter prospective studies are recommended to validate these findings.
Abstract

Keywords:
Chlamydia pneumoniae pneumoniachildrenimmunoglobulin arisk factorssevere pneumonia

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