Burden and Outcomes of Severe Pertussis Infection in Critically Ill Infants

Lahn Straney, PhD; Andreas Schibler, MD, FCICM; Anusha Ganeshalingham, FCICM; Janet Alexander; Marino Festa, MD, FCICM; Anthony Slater, MD, FCICM; Graeme MacLaren, MD, FCICM; Luregn J. Schlapbach, MD, FCICM


Pediatr Crit Care Med. 2016;17(8):735-742. 

In This Article

Abstract and Introduction


Objectives: Despite World Health Organization endorsed immunization schedules, Bordetella pertussis continues to cause severe infections, predominantly in infants. There is a lack of data on the frequency and outcome of severe pertussis infections in infants requiring ICU admission. We aimed to describe admission rates, severity, mortality, and costs of pertussis infections in critically ill infants.

Design: Binational observational multicenter study.

Setting: Ten PICUs and 19 general ICUs in Australia and New Zealand contributing to the Australian and New Zealand Paediatric Intensive Care Registry.

Patients: Infants below 1 year of age, requiring intensive care due to pertussis infection in Australia and New Zealand between 2002 and 2014.

Measurements and Main Results: During the study period, 416 of 42,958 (1.0%) infants admitted to the ICU were diagnosed with pertussis. The estimated population-based ICU admission rate due to pertussis ranged from 2.1/100,000 infants to 18.6/100,000 infants. Admission rates were the highest among infants less than 60 days old (p < 0.0001). Two hundred six infants (49.5%) required mechanical ventilation, including 20 (4.8%) treated with high-frequency oscillatory ventilation, 16 (3.8%) with inhaled nitric oxide, and 7 (1.7%) with extracorporeal membrane oxygenation. Twenty of the 416 children (4.8%) died. The need for mechanical ventilation, high-frequency oscillatory ventilation, nitric oxide, and extracorporeal membrane oxygenation were significantly associated with mortality (p < 0.01). Direct severe pertussis–related hospitalization costs were in excess of USD$1,000,000 per year.

Conclusions: Pertussis continues to cause significant morbidity and mortality in infants, in particular during the first months of life. Improved strategies are required to reduce the significant healthcare costs and disease burden of this vaccine-preventable disease.


Severe disease caused by infection with Bordetella pertussis (B. pertussis) is predominantly seen in infants and can include pneumonia, apnea, encephalopathy, and pulmonary hypertension.[1,2] Before the widespread implementation of vaccination strategies, pertussis caused large epidemics and was responsible for an estimated 10,000 annual deaths in the United States.[3,4] As a result of successful vaccination programs,[5] public awareness of this disease is low in most high-income countries. Despite significant reductions in mortality over the past decades, pertussis remains responsible for a significant proportion of childhood mortality on a global scale, with an estimated 89,000 annual deaths.[6] Therefore, pertussis is among the key diseases targeted in the Global Vaccine Action Plan by the World Health Organization.[7] Importantly, over the past decade, several high-income countries have reported outbreaks of pertussis infections, and there is concern about an increasing number of potentially preventable deaths in neonates and young infants.[8–11] A recent outbreak in Dallas County, TX, reported four deaths; of which, two occurred in infants younger than 60 days old.[12]

Infants with pertussis, particularly those less than 3 months old, frequently require monitoring or life support in PICUs, mainly for apneas or respiratory failure.[13] Hyperleukocytosis and pulmonary hypertension are severe manifestations and can present similarly to acute respiratory distress syndrome.[14] A recent U.S. study described clinical features of 143 children requiring PICU admission due to pertussis, with 43% requiring mechanical ventilation and a 9% fatality rate.[15]

Despite the ongoing impact on the health system of this severe yet preventable infection, population-based data in critically ill infants with pertussis are limited.[16] The aim of this study was to estimate the population-based incidence of severe pertussis in infants requiring intensive care admission and to investigate outcomes and explore specific risk factors leading to fatal outcomes.