Michigan health officials say the southeast part of the state is seeing a serious outbreak of hepatitis A cases.

An analysis by the Detroit Free Press found that Michigan has led the U.S. in hepatitis cases per capita this year, with more than 500 reported cases so far.

The Detroit News reports that there have been 20 deaths linked with hepatitis A in southeast Michigan since August 2016.

The Centers for Disease Control and Prevention says hepatitis A is an extremely contagious liver disease caused by the hepatitis A virus. It can be spread during sex or by eating contaminated food or water.

Health officials say the majority of cases involve drug users, homeless people and current or former inmates. The outbreak has particularly affected Wayne, Macomb and Oakland counties.

The Monroe News reports a case of hepatitis A has been confirmed in Monroe County. According to the paper, the employee works at the Tim Hortons at 404 S. Monroe St. The health department says anyone who ate or drank at the restaurant between Nov. 21 and Dec. 8 may have been exposed and should talk to a doctor. Anyone who may have been exposed may need a hepatitis A vaccination or immune globulin treatment.