Diners at a popular lower Hudson Valley restaurant may have been exposed to a highly contagious disease that attacks the liver.

On Monday, the Westchester County Department of Health confirmed a Winston restaurant employee worked at the Northern Westchester eatery while infectious with hepatitis A.

Anyone who was at the Mount Kisco restaurant from April 17 until May 1 may have been exposed to hepatitis A, health officials warn.

The Westchester County Department of Health is offering free preventive treatment for anyone who visited the restaurant during the time period. However, the treatment only works if given within two weeks of the day of exposure, ABC reports.

That means some people who were exposed can no longer get effective treatment. If you were at the restaurant on Tuesday, April 23, you must get treatment on Tuesday, May 7.

If you were at the Winston restaurant between April 17 and April 21, you should contact your doctor immediately, health officials say.

You only need to be treated if you haven't had a hepatitis A vaccination or a hepatitis A infection.

Hepatitis A is a highly contagious disease that attacks the liver, according to the New York State Department of Health. It's spread by the fecal-oral route by putting something in the mouth, even though it may look clean, that has been contaminated with the stool of a person with hepatitis A; through close person-to-person contact; or by eating or drinking contaminated food or water.

Symptoms include fever, jaundice (yellowing of skin), fatigue, loss of appetite, nausea, abdominal discomfort and dark urine.

The Winston restaurant is said to be working with health officials and will remain closed until staff and the restaurant has been inspected.

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