Guests who attended Ashton Kutcher's birthday party on Feb. 7th are being told to get themselves checked for Hepatitis. Held in the 'Socialista,' a New York club decked out to look like 40's Havana, it looks like party-goers might have left with more than just a Cuban cigar and a hangover.

The NY Board of Health has confirmed that a waitress at the event later tested positive for Hepatitis A. Officials aren't sure who gave it to her, but if I had to guess, I'd say that it was Madonna. Even Kutcher himself is being urged to go get himself checked out -- a screening for the all the partiers is set for today.

Guests included A-listers like Bruce Willis, Gwyneth Paltrow, Madonna, Kate Hudson and, of course Demi Moore -- if this thing turns out to be an celebrity epidemic, it could mean disaster for the Oscars.

Of course, it could be a practical joke. Doesn't this kinda seem like an episode of Punk'd?

[via PerezHilton]