Chest infection research raises asthma questions
08 April 2009

Chest infections in children do not cause asthma, but they do act as an indicator that the child has inherited a high genetic risk of asthma, according to recently published research.

Dr Simon Thomsen and colleagues studied over 8,000 pairs of twins, finding out from medical records which of the children had experienced severe chest infections, and which had developed asthma. They found that the rate of viral infections and asthma was more similar between identical twins than non-identical twins.

The researchers concluded that a child’s genetic makeup is likely to dictate both their risk of severe viral infections and their risk of asthma. So, if a child develops a severe infection, this might indicate that they’ve inherited a high risk of asthma, rather than suggesting that the infection itself will increase their asthma risk.

However, the results of this study seem to conflict with two other recently published research papers.

In October last year, American researchers discovered that children from age 0-3 years who wheezed in response to a rhinovirus infection, the most frequent cause of the common cold, were nearly 10 times as likely to develop asthma by the age of six as children who hadn’t wheezed.

Then in November 2008, another research paper was published, further strengthening the evidence that viruses directly cause asthma. These researchers discovered that children born four months before the winter peak of virus infections had the highest risk of asthma. That a child’s risk of asthma is directly related to when they’re born strongly suggests that viruses play a direct role. If this weren’t the case, a child’s risk would be unaffected by the timing of their birth.

Dr Elaine Vickers, Research Relations Manager at Asthma UK comments, ‘Although these researchers come to different conclusions, the likelihood is that they’re actually all correct.

‘Scientists around the world are now conducting vast studies to find out how our genes and environment interact. The chances are that our genes influence all sorts of things linked to asthma risk, such as our ability to fight off virus infections and the sensitivity of our skin and airways to things like pollen, dust and pollution.