Health officials say they are investigating outbreaks of hepatitis A among fans of the band The String Cheese Incident who are traveling from concert to concert.

"We've gotten reports of a number of hepatitis A cases among the young adults that attend those concerts," said Llelwyn Grant, a spokesman for the Centers for Disease Control and Prevention.

Potential sources of the outbreak include contaminated food or water, Grant said.

Like fans of Phish and the Grateful Dead, devotees of Boulder-based The String Cheese Incident spend their summers following the band across the country. Many camp out near the outdoor venues.

Band publicist Carrie Lombardi said there is no link between the band and the virus. But she said the band is working with health officials.

On the band's Web site, Hep A facts and figures are listed and a statement to fans is posted:

"Thanks everyone for your patience while we collected the facts surrounding the recent Hepatitis A issue at summer concerts. While it is certainly something that we should all be educated about and aware of, we are relieved to have learned, through conversations with the Center for Disease Control (CDC), that there is no reason to be alarmed and that with a bit of cooperation and consciousness, our community can contribute our part toward public safety."

Hepatitis A can cause nausea, diarrhea, fever, jaundice and fatigue. The illness, which is contagious, can be prevented through good hygiene and sanitation. Vaccination is the best prevention.

Grant said the CDC is working with health officials in California, where infections of 10 people -- five men and five women -- have been reported.

Illness onset occurred between June 1 and July 10, the band said on its Web site.

"Based on how this tour has traveled, a number of states may eventually be connected," she said.

Colorado health officials said they are in touch with the CDC about the outbreak. The band is scheduled to return to Colorado for concerts on Sept. 5 and 6.

The CDC is currently investigating the venue and camping sites throughout the United States to try to determine possible contaminated food or water sources, and to begin following the path of transmission.

"The String Cheese Incident has volunteered to allow the CDC to be on site during the Warfield and Trinity County shows. The CDC hopes that those folks within our community who have been traveling to concerts this summer can help out by answering a few questions. Mostly, they want to ask if you or someone you know has been sick. Please take the time to stop by their booth in the lobby if you think you can help," the band said.