Written by Kimiko Dunbar
Spoon Feed
Unvaccinated children with shortness of breath, age < 3.68 months (112 days) or WBC >27.93×10⁹/L, are at risk for severe pertussis; exchange transfusion is recommended for those with hyperleukocytosis and pulmonary hypertension.
Is bloodletting the new DTaP?
The incidence of pertussis has been increasing since the 1990s, with more reports of severe cases and fatalities in the past several years. Severe cases are linked to high leukocyte counts and the presence of pulmonary hypertension. Exchange transfusion can be used to lower leukocyte count, but there are no standard guidelines for its use.
This retrospective study examined 183 pediatric pertussis cases to identify risk factors for severe disease and to evaluate exchange transfusion. Severe pertussis was associated with age <3.68 months (or 112 days of life), no DTaP vaccination, shortness of breath, and WBC >27.93×10⁹/L (AUC=0.725). Multivariate analysis confirmed these as independent predictors. There were no differences in severity secondary to prematurity, CRP, platelet count, albumin, D-dimer, LDH, or fibrinogen. Among eight critically ill patients, exchange transfusion significantly reduced WBC and resolved pulmonary hypertension. Generalizability is limited given it was single-center and had a small number who received exchange transfusion (n=8).
How does this change my practice?
With increasing rates of pertussis and other vaccine-preventable illness, it’s helpful to know how to identify the most severe cases. I’ll be getting a CBC in patients with pertussis, with special attention for those with WBC >27.93. This study also highlights prior work demonstrating that pertussis can present without spasmodic cough; I won’t rule pertussis out based on absence of spasmodic cough alone. Finally, the association of increased severity with younger age reinforces the importance of timely vaccination, which could be used to encourage against a delayed vaccination schedule.
Source
Risk factors for severe pertussis in children and the application of exchange transfusion. Pediatr Res. 2025 May 15. doi: 10.1038/s41390-025-04118-6. Epub ahead of print. PMID: 40369242
