The Ashland-Boyd County Health Department reported on Tuesday that customers of both Waffle House restaurant locations in Boyd County were potentially exposed to the highly contagious virus by an infected foodservice worker.

“The single employee worked at each location during the infectious period,” according to the public health alert. “The window of possible exposure was Feb. 12-28.

The Waffle House restaurant owner and employees have cooperated fully with the local and state health officials to identify all employee contacts, according to the county alert. Waffle House employees are receiving post-exposure vaccinations.

Anyone who consumed foods or beverages at either of the Waffle House locations during the possible exposure period is urged to monitor themselves for signs of infection in the coming weeks. It can take up to 50 days after exposure for symptoms to develop, according to the U.S. Centers for Disease Control and Prevention.

Some of the Waffle House customers still have time to receive post-exposure vaccinations. The after-the-fact injections must be giving within 14 days of exposure or they are not effective. The last date for the post-exposure vaccine is March 13, according to the county health department.

Hepatitis A is a liver disease caused by a virus. Symptoms, when present, can include fatigue, low appetite, stomach pain, nausea, and the yellowing of the eyes or skin. Some adults and most young children do not develop symptoms while infected, but they can spread the virus. The virus can contaminate foods, beverages, surfaces, clothing, bed linens — often because of inadequate handwashing. Hepatitis A can also be spread by close personal contact with an infected person, including sexual contact and sharing needles.

In Kentucky, 148 cases have been confirmed through laboratory testing since Jan. 1, 2017. The state health department officially declared the outbreak on Nov. 28, 2017. Multiple Kentucky counties have reported confirmed outbreak cases, but Louisville in Jefferson County has the vast majority at 124 as of Tuesday. Of the state’s confirmed cases, 107 of the people have had such severe symptoms that they required hospitalization. The person who died was a Jefferson County resident.

The outbreak strain was first identified in California, but cases have been confirmed in several states, including Michigan, Utah, Oregon and Nevada. Nationwide more than 1,200 people have been confirmed in the outbreak, with the majority requiring hospitalization. More than 40 deaths have been confirmed.