Economists are slashing this year's growth forecasts for Asian economies due to the fallout from a fast-spreading killer virus but say the full impact will depend on whether it can be brought under control.

Businesses from hotels and restaurants to airlines are bearing the brunt of the health crisis which has slashed tourism in the region.

Severe Acute Respiratory Syndrome (SARS), a virulent form of pneumonia which has no cure, has killed nearly 80 people worldwide and affected more than 2,000 people, mostly in East Asia.

Pradumna Rana, an economist at the Asian Development Bank (ADB), said the institution may have to downgrade this year's forecast for East Asian gross domestic product (GDP) growth from 5.6 per cent, but he does not know by how much.