The SARS virus that caused worldwide panic in 2003 and claimed about 800 lives invades its victims using "fatty rafts" on cell membranes, Chinese scientists have said.

These lipid rafts, or fatty acids, are cholesterol-enriched sections of the cell membrane, they said.

How the SARS virus enters and infects its host cells has always been controversial, but health experts consider such details crucial as they provide important clues on how the virus can be stopped.

In an article published in life sciences journal Cell Research, scientists from China and the United States described how they cultured cells, exposed them to the virus and then observed how it was engulfed - in a process called endocytosis - by the host cells.

"The virus gets in through endocytosis and then it is aided by lipid rafts along the way," Jiang Chengyu, a professor at the Peking Union Medical College in Beijing, said yesterday in a telephone interview.

But Jiang said designing an "inhibitor" to stop the virus was still a long way off.

"This finding helps us understand the puzzle a little more, but as for creating an inhibitor, there is still a long way to go," she said.

Experts say the palm civet and certain species of bats are natural hosts of the SARS virus, and some of them caution that SARS could reemerge and become a global threat.

The first case of SARS in China was identified in Guangdong province in late 2002.

The government banned the rearing and consumption of civets in an effort to remove a vital link in the chain after scientists found SARS virus in them.

The research article can be found at www.nature.com/cr.

(Agencies via China Daily January 30, 2008)