Death toll from Australia's thunderstorm asthma rises to eight

After a rare asthma event brought by a thunderstorm attacked Melbourne a week ago, eight people have been killed and one other remained in intensive care, Australian authorities said Tuesday.

The victims are among some 8,500 people receiving hospital treatment as they all suffered breathing difficulties in the wake of the thunderstorm.

So far, the most reported cause of the situation is that last week's storm broke grass pollen into fragments so tiny that can be inhaled deep into lungs and stem people's breath.

However, scientists are yet uncertain whether the rain caused the grass seed to swell and rupture or the wind and heat helped the tiny fragments to spread.

According to media reports, around a third of patients who suffered asthma attacks this time reported never having asthma before.

Local medical facilities and service were stretched beyond their limits as the number of patients rose at a surprising speed and the situation deteriorated rapidly.

"This was a health emergency of an unprecedented scale," said Jill Hennessy, the health minister of Victoria State.

The last thunderstorm asthma in Melbourne was in November 2010 but that was never as severe as the outbreak this time.

Though this asthma attack was unusual, similar events also recorded in the United States, Canada, Britain and Italy. Endi