How 'Dirt' Could Educate The Immune System And Help Treat Asthma

Speaking at the launch of the BA Festival of Science today,Professor Peter Openshaw, explains that a lack of exposure to dirt andcommon viral infections among children could be behind the rise in thelevels of asthma.

Professor Openshaw, from Imperial College London, and based atSt Mary's Hospital, says: "Although we have seen a dramatic decline inmany previously common childhood infections over the past 100 years, wehave also seen a considerable rise in the prevalence of diseases suchas asthma. The increase in asthma cannot be blamed purely on changes ingenetic risk, so must be down to environmental factors."

Scientists have called this the 'hygiene' hypothesis, with alack of exposure to viruses and other environmental factors meaningchildren are not able to build up resistance, and can become moresusceptible to disease later in life. They also believe having manyolder siblings, attending day care at an early age, or growing up on afarm can help in promoting resistance to disease.

Studies have shown that most common colds can help protectagainst wheezing in later childhood, and other childhood infectionssuch as chickenpox also provide a level of protection.

Professor Openshaw adds: "The challenge now is to find ways ofreproducing the protective effects of early childhood infections, whilereducing the burden of actually getting these infectious diseases.Knowing exactly which 'dirt' provides the best education for the immunesystem, and how to mimic its affects in a cleaner environment, could bethe key to reducing the rise in the prevalence of asthma and relateddiseases."

Professor Openshaw is a respiratory medicine researcher,looking at immunological responses to diseases such as asthma, thecommon cold and other lung diseases.