Louisville, KY, residents are getting another in what’s been a series of public warnings about hepatitis A.

This time, anyone who dined at a local White Castle restaurant between April 6 and April 20 is advised they might have been exposed to the virus and should get vaccinated. That’s because a White Castle employee who was diagnosed with hepatitis A was working during those dates in the restaurant at 3701 Seventh Street Rd. in Louisville.

Since Jan. 1, 2017, the Kentucky Department of Public Health (KDPH) has identified 311 confirmed cases of acute hepatitis A., a liver disease caused by the hepatitis A virus. Of those, 218 people have required hospitalization, and one died.

Since April 1, the outbreak has grown by 41 additional confirmed cases, mostly in the Louisville area. The Kentucky cases are associated with ongoing hepatitis A outbreaks in Utah, California, Michigan and Nevada.

Public health authorities in Louisville are recommending vaccination as the best way for people to protect themselves against the virus. More than 14,000 people have been vaccinated in Louisville since the start of the outbreak.

Anyone who ate or drank foods or beverages at the White Castle location during the recent dates is urged to ask their doctor about the post-exposure vaccination. If the vaccine is not given within 14 days of exposure it is not effective.

White Castle is providing vaccines to all its employees.

The Department of Public Health and Wellness and the University of Louisville Global Health Center are offering discounted vaccines for food service employees at $25 each instead of the usual $65 charge. Hospitality businesses with more than 20 employees can schedule a public health nurse to visit their locations and provide the vaccinations.

Symptoms of hepatitis A typically take 15 to 50 days after exposure to surface. They usually include fatigue, decreased appetite, stomach pain, nausea, darkened urine, pale stools, and yellowing of the skin or eyes.

Anyone experiencing such symptoms should see a doctor as soon as possible. hepatitis A is transmitted by the “oral-fecal” route, meaning contaminated by feces spread by food or water. Microscopic amounts of the virus can infect many people, especially if people who handle, prepare, serve or consume food fail to properly wash their hands.

Kentucky is among several states advising visitors to get a hepatitis A vaccine.