Having measles before the age of 3 and two or more younger siblings seems to protect against asthma, finds a study in Thorax.
Researchers from the University of Aberdeen investigated the association between the development of wheezing and atopy (allergic response) in adulthood among over 300 people, who, as children had been part of a health survey in 1964. They were followed up for over 30 years, during which time allergic responses and evidence of antibodies to hepatitis A, toxoplasmosis, and Helicobacter pylori, a bacterium implicated in ulcers and possibly heart disease, were tested for. Detailed questionnaires on asthmatic symptoms were also completed.
People with persistent cough and phlegm with wheeze were more likely to have antibodies to hepatitis A and Helicobacter pylori. But antibody positivity was no associated with either the development of wheeze or atopy as an adult. But having two or more younger siblings and measles before the age of 3 was significantly associated with a lower risk of asthma.
Previous research from the same team has indicated that other factors, such as diet, may be important. But exposure to bacteria and viruses in infancy and childhood might be important in protecting against asthma. And, say the authors, protection may be conferred by a particular type of infection that is capable of altering the immune response for years ahead. That infection might be the measles virus, they say.
Dr David Godden, Department of Environmental and Occupational Medicine, University of Aberdeen, Scotland.
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