Dr. Bradley Connor, a New York specialist in infectious disease, says hepatitis A virus is spread by close personal contact or by eating food or drinking water contaminated with the virus. Symptoms may include fatigue, jaundice, appetite loss, abdominal pain, nausea, diarrhea and fever.

Recent revelations about a grocery store produce worker in Buffalo with hepatitis A led to more than 10,000 people seeking immunizations at a county clinic. After it was disclosed that a bartender with hepatitis A worked at actor Ashton Kutcher's 30th birthday, 700 people who attended -- including actor Bruce Willis and pop singer Madonna -- got vaccinations.

New York health officials have urged anyone exposed to hepatitis A to get immunized.

"If you believe that you have been exposed, talk to your doctor about whether you should receive an immunization against hepatitis A," Connor says in a statement. "This treatment is intended to help boost your immunity and reduce your risk of developing a full-blown infection."

Hepatitis A can be spread by contaminated food and water. However, hepatitis B and hepatitis C are spread by exposure to infectious blood and body fluids.