Background: The hygiene hypothesis suggests that infectious diseases in early life reduce the risk of allergic diseases.
Objective: To investigate the association between measles infection during early childhood and the prevalence of allergic diseases, lung function, bronchial hyperresponsiveness (BHR), and sensitization in later childhood.
Methods: A survey was conducted 5 years after a nationwide measles outbreak in Korea. From September 1 through November 30, 2006, we obtained information on history of measles and allergic diseases but not of measles vaccination through a questionnaire completed by 1004 schoolchildren aged 6 to 7 years. Furthermore, we measured measles antibody titers and performed skin prick tests, pulmonary function tests, and methacholine challenge tests. Children were divided into groups based on their history of measles infection and antibody titers.
Results: Prevalence of measles infection was 8.2%. Children with both a positive measles history and a positive antimeasles antibody had significantly higher antimeasles antibody levels than those without a measles history. The prevalence of current rhinitis (adjusted odds ratio [aOR], 1.86; 95% confidence interval [CI], 1.02-3.40), rhinitis ever (aOR, 2.17; 95% CI, 1.19-3.94), and current BHR (aOR, 1.98; 95% CI, 1.04-3.78) was significantly higher in the group with a positive measles history compared with the group with a negative measles antibody. No differences were found among groups in the prevalence of asthma, lung function, provocation concentration that caused a decrease in forced expiratory volume of 1 second of 20%, or sensitization.
Conclusion: Early measles infection was associated with increased prevalence of rhinitis and BHR at the age of 7 years but has no effect on the development of asthma and allergy at the age of 7 years. This study indicates that common childhood infections such as measles in early age do not protect against later development of allergic diseases.