Risk factors for severe pertussis in children and the application of exchange transfusion.

Objective: To identify risk factors for severe pertussis and assess the efficacy of exchange transfusion in children.

Methods: We analyzed pediatric pertussis cases, comparing mild and severe presentations using hospital data on demographics, symptoms, lab findings, echocardiography, and complications, and employed ROC analysis to determine severe pertussis risk factors.

Results: Our study analyzed 119 mild and 64 severe pertussis cases, with severe cases characterized by earlier onset, spasmodic cough, shortness of breath, and rales. Risk factors for severity included lack of DTaP vaccination and pulmonary hypertension. Severe cases also showed higher WBC and lymphocyte counts and more mixed infections. Logistic regression identified shortness of breath, no DTaP, younger age, and high WBC as severity predictors (P < 0.05). ROC analysis predicted severity with age < 3.68 months and WBC > 27.93 × 10⁹/L (AUC = 0.606, 0.725; P < 0.05). Exchange transfusion in patients with rising WBC and shortness of breath normalized pulmonary hypertension and led to recovery.

Conclusion: Clinicians should closely monitor unvaccinated children with shortness of breath, onset before 3.68 months, and WBC > 27.93 × 10⁹/L for severe pertussis risk. Exchange transfusion is advised for those with WBC > 40 × 10⁹/L and pulmonary hypertension, showing significant therapeutic benefit.

Impact: This study delineates four key predictors of severe pertussis in children: younger age, lack of DTaP vaccination, shortness of breath, and elevated white blood cell (WBC) counts. We establish WBC > 27.93 × 10⁹/L as a robust quantitative biomarker for severity prediction (AUC = 0.725), providing clinicians with an objective threshold to prioritize intensive monitoring and intervention. Exchange transfusion demonstrates efficacy in reducing WBC levels and resolving pulmonary hypertension in critical cases. These findings reinforce the imperative of DTaP vaccination to prevent severe disease and inform evidence-based management protocols.