Clinical characteristics and predictors of Mycoplasma pneumoniae pneumonia coinfection with Bordetella pertussis in children

This study aimed to investigate the clinical characteristics of Mycoplasma pneumoniae (MP) pneumonia coinfection with Bordetella pertussis (BP) in children and to determine the predictors of BP coinfection. Children with MP pneumonia (MPP) admitted to The First People's Hospital of NanKang District between January 2024 and January 2025 were screened. Patients with BP coinfection were assigned to the study group, while those with mono-infection of MP were assigned to the control group at a 1:1 ratio, matched by age and admission time. Clinical data were compared between the 2 groups. Multivariate logistic regression analysis was performed to evaluate the association between BP coinfection, severe pneumonia, and azithromycin (AZM) treatment failure. Receiver operating characteristic (ROC) curve analysis was used to identify the potential predictive factors for BP coinfection. A total of 1475 hospitalized children with MPP were screened. Forty children were enrolled in the study and 40 in the control group. Children in the study group had a higher incidence of fever and spasmodic cough as well as a longer duration of fever and cough. They also exhibited an elevated white blood cell (WBC) count and lymphocyte (LYM) percentage, higher rates of severe pneumonia, oxygen therapy, bronchoalveolar lavage, methylprednisolone use, longer hospital stays, and higher hospitalization costs. Coinfection with BP was associated with severe MP pneumonia (P = .017) and treatment failure (P = .038). The area under the ROC curve (AUC) values for WBC count, LYM percentage, fever duration, and cough duration were 0.644 (95% CI: 0.521-0.768, P = .028), 0.641 (95% CI: 0.521-0.760, P = .032), 0.638 (95% CI: 0.516-0.761, P = .036), and 0.698 (95% CI: 0.576-0.820, P = .003), respectively. BP coinfection in children with hospitalized MPP is associated with an increased risk of severe pneumonia and treatment failure, which may complicate clinical management and increase disease burden. WBC count, LYM percentage, fever duration, and cough duration could serve as predictive factors for BP coinfection.