But meantime, parents and schools should play a greater role in helping to control a disease whose prevalence has increased 20 times in recent years.

Asthma expert Dr Malcolm Howitt, president of the Caribbean Allergy and Respiratory Association (CARA), made these comments in an address to the monthly meeting of the Barbados Labour Party's St George North branch on Sunday.

"All the things like the house dust mite, the cats and the dogs we thought in the past were major triggers of asthma, we now know from recent findings that . . . is not the case," he said.

"In fact, some studies actually show that when children grow up with cats, that actually protects them from developing asthma. In other words, they have less asthma.

"Also it has been thought that the main trigger of asthma is really viral infections."

Hygiene hypothesis

As to what caused asthma, Howitt said a "hygiene hypothesis" had been advanced by the experts. This meant the more time a child's immune system spent fighting off bacteria, parasites and viruses, the more tolerance the system had for the irritants that caused asthma.

According to this "hygiene hypothesis", the immune system evolved two types of biological defences. When one defensive system lacked practice fighting bacteria and viruses, perhaps from an overly sanitary lifestyle, the other system became too powerful and overreacted – as an allergic reaction – to harmless substances like pollen.

Howitt said asthma was a chronic disease, which did not go away quickly like other ailments, and asthmatics needed to take their medication on a daily basis.

He said schools across Barbados should have equipment for helping their asthmatics, including "peak-flow meters" that would indicate the state of the asthma, and nebulisers (which turn drugs from a liquid into a fine spray for inhaling).

Parents needed to ensure their children used the inhalers regularly and correctly, he added. (TY)