[The association between pertussis during infancy and childhood asthma]

The prevalence of pertussis and asthma in Israel increased during the last decade.

To examine the association between pertussis during infancy (<6 months of age) and childhood asthma (3-9 years).

We compared two groups of children >6 months of age who presented to the emergency room with a cough. Pertussis was diagnosed in the study group (SG) and ruled-out in the control group (CG) by Polymerase Chain Reaction. Asthma was diagnosed by a questionnaire.

Out of 393 children, presented to the emergency-room, 44 in the SG and 52 in the CG were detected and completed the questionnaire. There was no significant difference between the groups in their demographic data (time of presentation [median and range] 2.2 [1-6] months vs. 3 [1-6] months, gender and place of residence). There were more Arab children in the SG (38% vs. 15%, p<0.05). More children were hospitalized at presentation in the SG (75% vs. 46%, p<0.01). There was no significant difference between the groups in the rate of pertussis vaccination or in genetic or environmental variables that could affect asthma prevalence. There was no significant difference between the study and control groups in the prevalence of asthma (18% vs. 9.6%, p=0.24) or atopic diseases or in childhood asthma in children hospitalized at presentation (18.2% vs. 8.3%, respectively, p=0.44). However, the rate of the combination of asthma and/or atopy in hospitalized infants was significantly higher in the SG (33% vs. 8.3%. p=0.03).

Our study did not show that pertussis during infancy significantly increases the prevalence of childhood asthma.