Asthma sufferer 10-year-old Anastasia Savvas, pictured at home in Plymouth, South Australia, went for five years without an attack. Picture: James Elsby Source: the Australian

DEATHS from asthma and the prevalence of the disease among five to 34-year-olds have declined substantially over the past decade, despite concern among experts the condition is still poorly managed by GPs.

The latest Australian Institute of Health and Welfare data on the disease shows two million people have asthma and the mortality rate is the fourth-highest in the developed world.

Experts are worried that fewer than 9 per cent of those who see their general practitioner with an asthma problem are given an asthma management plan or encouraged to use preventer medication, despite this being recommended practice.

Anastasia Savvas, 10, who was diagnosed with asthma as a toddler, thought she had outgrown the condition until a virus triggered an attack last year that left her hospitalised for three nights.

"It surprised me. It came just like that, out of the blue, after she had no symptoms for five years," says Anastasia’s mother, Sophie, who had difficulty getting a diagnosis from several GPs.

Ms Savvas says her daughter is managing well, using a preventer medication four times a day.

The prevalence of asthma among five to 34-year-olds declined by more than 25 per cent between 2001 and 2008 but remained stable in adults aged 35 years and over, the AIHW report Asthma in Australia shows. there were 411 deaths from asthma in 2009 but the mortality rate dropped by 45 per cent between 1997 and 2009.

Indigenous Australians and people living in areas of lower socio-economic status are more likely to be hospitalised for asthma than those in more wealthy areas, the report shows.

Guy Marks, who helped produce the report, says the causes of asthma and the reasons the rate of disease went up and down remain a mystery.

The reduction in prevalence of the disease and improved treatments were partly responsible for the reductions in the death rate, said Professor Marks, who is from the Australian Centre for Asthma Monitoring.

The chairman of Asthma Australia’s medical committee, Simon Bowler, said the report was good news because it showed fewer Australians were suffering asthma symptoms and fewer people were being hospitalised and dying from the disease.

However, he said the decline in asthma had undermined the hypothesis that the disease was caused by the lack of exposure to bugs and dirt in the first 12 months of a child’s life.

"It remains one of the mysteries of our time and it is frustrating we don’t know the cause," mr Bowler said.