Most of the hepatitis-A-in-restaurants events follow this formula: A food handler or a server shows symptoms, the virus is confirmed, health folks provide patrons with shots and hopefully no one else gets sick.

The story in Napa County is a bit different: According to the Napa Valley Register, five people, including two food handlers at restaurants are ill and it’s unclear whether this cluster is an outbreak or a coincidence.

The source of the infection is under investigation. This is the first time in more than five years that acute Hepatitis A infection has been confirmed in a Napa County resident, the county said.

Two cases involve employees of La Toque restaurant and BANK Café and Bar in The Westin Verasa Napa. The source of these infections is unknown and there are no known cases involving customers, the county said in a news release.

The other three cases have no known association with these locations or other public settings, the county said.

In a county news release, Ken Frank of LT Napa Partners, which owns and operates La Toque restaurant and BANK Café and Bar, said, “La Toque restaurant and BANK Café and Bar take the health of our guests very seriously. We have strict health standards in place, and we are cooperating fully with Napa County Public Health to identify the source of the virus.”

Don Shindle, general manager of The Westin Verasa Napa, said, “We continue to assist Napa County Public Health and are taking all appropriate measures to ensure the safety of our guests and associates. We are confident that Frank and his team are diligent in following their high standards and working closely with Napa County Public Health.”