FARGO, NORTH DAKOTA (REUTERS) - Catholics in North Dakota were warned to watch for symptoms of hepatitis A after a bishop with the disease served communion at four churches, putting worshippers at risk, state officials said.

Bishop John Folda of the Catholic Diocese of Fargo got hepatitis from contaminated food while in Italy last month for a conference of newly ordained bishops, Ms Aliceyn Magelky, spokesman for the diocese, said on Friday.

Bishop Folda served communion during mass at three churches in Fargo and one church in Jamestown between Sept 27 and Oct 7, according to the North Dakota Department of Health. The Mass in Jamestown was at a convention of priests.

"He feels terrible about it," Ms Magelky said. "He did not know when coming back that he had contracted the virus or he would have refrained from participating in mass much sooner."

Ms Magelky said Bishop Folda is feeling better and has not been infectious since Oct 16, but is still not on a full work schedule. Priests who attended Bishop's Folda's mass in Jamestown were notified directly of the bishop's illness, she said.

Hepatitis A can cause infection of the liver and is found in the faeces of infected people, according to the health department. It is most often spread when people with the disease fail to wash their hands thoroughly and then touch other people.