PURPOSE OF THE STUDY.
To determine if past common childhood illnesses and infectious diseases including pneumonia, pertussis, measles, mumps, rubella, chickenpox, and diphtheria are associated with an increased risk of asthma persisting at various ages
In the Tasmanian Longitudinal Health Study, 8583 Tasmanian schoolchildren were surveyed in 1968 at age 7 years and again at age 13 years.
In 2004, a detailed respiratory questionnaire was completed by 5729 of the original participants. Each child’s history was cross-referenced for a history of measles, mumps, rubella, chickenpox, diphtheria, and pertussis and immunizations against diphtheria, pertussis, tetanus poliomyelitis, and smallpox. Associations with current, persisting, or incident asthma were examined by using regression techniques.
There was no association between any childhood infectious disease and current asthma at ages 7, 13, 32, and 44 years. Pertussis was associated with reduced odds of asthma persisting at age 13, whereas chickenpox and rubella indicated reduced odds of asthma persisting to age 32. The incidence of asthma was associated with pertussis in preadolescence and with measles in adolescence. As infection load increased, there was a decrease in the incidence of asthma risk in adult life. Childhood pneumonia was associated with current asthma at ages 7 and 13 after adjustments for other factors including eczema but did not reveal an association between childhood pneumonia and asthma persisting from childhood to ages 13, 32, and 44 years.
Overall, childhood infectious diseases protected against asthma persisting in later life. Pertussis and measles, however, were associated with an increased risk of incident asthma in preadolescence and adolescence, which does not support the original hypothesis. History of pneumonia was the most relevant finding in persisting asthma in 7- and 13-year-olds.
The authors suggest a few explanations for these results. (1) Pertussis and measles may be predisposing these individuals to pneumonia and thus increasing asthma incidence. (2) Measles virus may downregulate inleukin-12 and upregulate inleukin-4, shifting the immunity. (3) Increased incidence related to pertussis may be in part to failed pertussis immunity rather than pertussis itself; however, this was not consistent when comparing history of immunizations. This is a relevant and interesting study. The exploration of predisposing factors for asthma is important to understanding asthma. Many parents wonder if their child’s previous infections may be possible causes for their asthma, especially with no family history. We look forward to addition research comparing infectious disease to asthma risk.
- Copyright © 2013 by the American Academy of Pediatrics