Damon arrives at the Film Cinema's Place in Venice during the 68th Venice Film Festival
Matt Damon (C) ,cast member of "Contagion", arrives at the Film Cinema's Place during the 68th Venice Film Festival September 3, 2011. Reuters

Not even the A-listers are spared in Contagion, a star-studded movie directed by Steven Soderbergh that recreates the outbreak of a global pandemic.

Audiences used to seeing the most famous faces last longest will be in for a surprise when they watch the slick, globe-trotting picture which is in competition at the Venice film festival.

The ensemble cast includes Gwyneth Paltrow, Matt Damon, Jude Law, Kate Winslet, Laurence Fishburne, Marion Cotillard and Jennifer Ehle, most of whom were in Venice for the world premiere on Saturday.

Soderbergh, an Oscar winner for Traffic and best known for his Ocean's crime capers, said the complex nature of the film made Hollywood heavyweights particularly important.

It's very helpful to have movie stars playing as many of these roles as you can, because you're throwing so many characters and so much information at the audience it's very helpful for them to get a sort of reference point, he told reporters in Venice.

There's a reason that movie stars have existed since the beginning of cinema, he added after Contagion was warmly applauded at a press screening ahead of the red carpet premiere.

It's good for audiences -- they like to have people they can identify with.

Contagion opens with a couple played by Paltrow and Damon who find themselves at the center of a global emergency that goes on to claim millions of lives.

Cotillard and Fishburne play health officials trying to get to the bottom of the disease in a race against time, while Law portrays a journalist and blogger who challenges the official line.

SARS AN INSPIRATION

At one point, one scientist irked by his questioning turns to him and says: Blogging is not writing. It's graffiti with punctuation.

Soderbergh weaves the bigger themes of fear, panic and globalisation together with individual tales of sacrifice and selfishness, hopping from Hong Kong to London to the United States as he does.

Paltrow was asked when she would allow her pre-teen children to watch Contagion, which features death, violence and a scene where a dead character's scalp is peeled back during an autopsy.

My kids can't even watch (children's comedy) 'Babe', so I don't know, probably not for a while.

She added that she did not see the death of central characters as any kind of judgment on the lives they led in the movie.

I think that if death by virus was a punishment for extra-marital affairs there may be only about three dudes left in this room right now, she joked at a packed press conference. Maybe less because we're in Italy.

Script writer Scott Burns said the story was partly based on the real-life outbreak of SARS in China in 2003.

Soderbergh, who said he would shortly be taking a break from film making, added: All of the science in the film had to be accurate, all of the scenes in which the virus was discussed or shown visually had to be absolutely realistic or plausible.

Otherwise we felt we weren't advancing our ideas very well or contributing to this genre very well.