Predictors of disease severity in children hospitalized for pertussis during an epidemic

Helen Marshall, Michelle Clarke, Kavita Rasiah, Peter C Richmond, Jim Buttery, G Reynolds, Ross Andrews, Michael D Nissen, Nick Wood, Peter McIntyre

Research output: Contribution to journalArticlepeer-review


Background: Australia recently experienced its worst pertussis epidemic since introduction of pertussis vaccine into the National Immunisation Program. This study aimed to determine factors associated with severe pertussis in hospitalized children during an epidemic using a novel pertussis severity scoring (PSS) system. 
Methods: This prospective, observational, multicenter study enrolled children hospitalized with laboratory confirmed pertussis from 8 tertiary pediatric hospitals during a 12 month period (May 2009-April 2010). Variables assessed included demographics, clinical symptoms and relevant medical and immunization history. Cases were scored using objective clinical findings with cases classified as either severe (PSS > 5) or not severe (PSS ? 5). Logistic regression models were used to predict variables associated with severe disease. 
Results: One hundred twenty hospitalized children 0-17 years of age were enrolled with a median PSS of 5 (interquartile range 3-7). Most (61.7%) were classified as not severe with 38.3% (46/120) severe. Most severe cases (54.3%) were <2 months of age. Presence of coinfection [odds ratio (OR): 4.82, CI: 1.66-14.00], <2 months old (OR: 4.76, CI: 1.48-15.32), fever >37.5C (OR: 5.97, CI: 1.19-29.96) and history of prematurity (OR: 5.00, CI: 1.27-19.71) were independently associated with severe disease. A total of 70 cases in children ?2 months of age, almost a third (n = 23) had not received pertussis vaccine. 
Conclusions: Most severe pertussis occurred in young, unimmunized infants, although severe disease was also observed in children >12 months of age and previously vaccinated children. Children admitted with pertussis with evidence of coinfection, history of prematurity or fever on presentation need close monitoring. 
Original languageEnglish
Pages (from-to)339-345
Number of pages7
JournalPediatric Infectious Disease Journal
Issue number4
Publication statusPublished - 2015


Dive into the research topics of 'Predictors of disease severity in children hospitalized for pertussis during an epidemic'. Together they form a unique fingerprint.

Cite this