Unwashed hands probably have led to an outbreak of hepatitis A in several Illinois Quad-City region counties, and the size of its spread has captured the attention of state and local health officials.

Nineteen confirmed and two suspected cases of the contagious disease have been reported among residents living in Rock Island County as well as Henry, Mercer, Warren and Woodford (near Peoria) counties, Illinois Department of Public Health officials announced Thursday.

Hepatitis A is rarely fatal, and most people recover in a few weeks without any complications. It does not have potential to permanently damage the liver, as other forms of hepatitis do, said Dr. Bill Langley, medical director of Genesis Health Group. Individuals who suspect that they have the illness should contact their doctor or another medical professional.

State and local public health officials said Thursday that they are working to determine the source of the illness as quickly as possible.

Theresa Foes, spokeswoman for the Rock Island County Health Department, declined to identify any specific business locations being checked as the possible source of the outbreak.

"When hepatitis A exists in a community, it can end up being spread at other establishments, homes, gathering places, picnics, work sites and the like," she explained.

"In all likelihood, there are several sources for this."

Public health officials are interviewing people who are ill and taking their histories in an effort to track the source of the disease, Foes said. "We are in food establishments every day, in many kitchens, churches, festivals," she added.

Foes declined comment about news reports that employees of a McDonald's restaurant in Milan, Ill., were tested Wednesday for hepatitis A.

The business on U.S. 67 was closed Thursday. A sign was posted on the window of every door and at the drive-thru area. Written all in capital letters, the sign read: "Sorry for any inconvenience, but we are closed until further notice."

Workers could be seen inside the building about 6 p.m. Thursday, sweeping floors and scrubbing chairs, including the type used for toddlers.

Kevin Murphy, owner of the business, could not be reached for comment by the Quad-City Times.

The size and type of this outbreak is not often seen because children, since 1995, have been vaccinated against hepatitis A, Langley said. Adults may be more susceptible to the virus because many of them have not been immunized. At least three cases of hepatitis A were reported last year in Scott County, according to health officials there.

The hepatitis A virus exists in human stools and often is carried on the hands of a person who does not wash their hands after using the bathroom.

"You can become infected by direct contact with a person who does not practice good hygiene or by consuming food or drink handled by an infected person," said Dr. Damon Arnold, the public health director for the State of Illinois.

The outbreak is one more reason why every business should have good hand-washing procedures and why all people should take personal responsibility for washing their hands after using a restroom, Foes said.

Hepatitis A has been around for many years, but it used to be called "yellow jaundice," Langley said. Some people might fight off the disease and never realize they had it in the first place. Once an individual recovers from hepatitis A, the person will have immunity against it.