Madonna and Demi Moore have been warned to have a hepatitis A injection.
The stars are among a host of Hollywood celebrities who have been advised by doctors to have the preventative injection after a bartender at Ashton Kutcher's 30th birthday party in New York's Cafe Socialista bar was found to have the infectious disease.
Other celebrities who may have to seek medical attention after attending the party on February 7 include Bruce Willis, Gwyneth Paltrow, Kate Hudson, Liv Tyler and new mom Salma Hayek. Hepatitis A can be contracted through contaminated food or drinking water and infections often occur in places with poor sanitation.
Health inspectors issued a warning to the club owners on Wednesday night after finding no soap in the rest rooms or behind the bar for staff to wash their hands before serving food and drinks.
Dr. Sharon Balter, medical epidemiologist at the New York City Department of Health and Mental Hygiene, said: "We are asking these bar patrons to get this vaccination as a precautionary measure."
Officials in the city will be offering free vaccinations to prevent the disease - which attacks the liver and includes symptoms such as jaundice, fatigue, abdominal pain, diarrhea and nausea - at a public school in New York this afternoon.
Armin Amiri, the owner of Cafe Socalista, said: "Although no additional cases of illness have been identified, the New York City Department of Health is urging customers to get the vaccination as a precautionary measure."
The infected bartender, who has not been named, also worked at the club after 8pm on February 8 and after 10pm on February 11. It is estimated that 800 people visited the club during the time the bartender was working.