Characteristics and outcomes of children admitted to paediatric intensive care units with life-threatening pertussis infection in Great Britain 2023-2024

Abstract

Objectives: Describe clinical characteristics, treatment and outcomes of children treated for life-threatening pertussis in paediatric intensive care units during the 2023-2024 outbreak in Great Britain.

Design: National multi-centre audit.

Setting: All paediatric intensive care units (PICUs) in Great Britain.

Patients: Between November 2023 and June 2024, 54 children with a proven diagnosis of Bordetella pertussis as the primary reason for intensive care admission requiring invasive ventilation.

Interventions: None.

Main outcome measures: Mortality on PICU, length of stay and number of invasive ventilation days.

Results: Median admission age 43 days, with peak blood white cell count (WCC) from 6×10⁹/L to 149×10⁹/L. 23% of infants' mothers were vaccinated during pregnancy (national average 59%). Mortality was 11/54 (20%), with 10 in infants <3 months. The survivor with the highest WCC peaked at 82×10⁹/L prior to exchange transfusion (XT), and the highest peak WCC in a survivor without XT was 71×10⁹/L. Eighteen patients underwent 27 XTs for leucoreduction, initiated at median peak WCC of 54×10⁹/L (range 32-148). All who died had XT planned, with nine completing. None with a peak WCC of <51×10⁹/L died, although four patients underwent XTs. In patients with rising WCC, survivors' rise rate was lower than those who died (0.23×10⁹/L/hour vs 1.4×10⁹/L/hour).

Conclusions: In children invasively ventilated due to Bordetella pertussis, higher peak WCC, rapid WCC rise and a primary admission reason other than apnoeas are associated with mortality. XTs can be avoided in WCC <50×10⁹/L. Maternal vaccination rate was lower in this cohort than the general population.

Keywords: Infectious Disease Medicine; Intensive Care Units, Paediatric.