WESTON – Marathon County’s first norovirus outbreak that sickened abut 100 people has been traced to Jimmy Johns in Weston, health officials confirmed Thursday.

The sandwich franchise, at 3910 Schofield Ave., closed briefly to undergo thorough cleaning and is not considered a health risk at this time, officials said.

The Marathon County Health Department began receiving reports of illnesses on April 7 and has not received any new reports since April 12, said Marathon County Health Officer Joan Theurer.

Norovirus infection can cause the sudden onset of severe vomiting and diarrhea, according to the Mayo Clinic. The virus is highly contagious and commonly spread through food or water that is contaminated during preparation or contaminated surfaces. You can also be infected through close contact with an infected person.

Diarrhea, abdominal pain and vomiting typically begin 12 to 48 hours after exposure. Norovirus symptoms last one to three days, and most people recover completely without treatment. However, for some people — especially infants, older adults and people with underlying disease — vomiting and diarrhea can be severely dehydrating and require medical attention.

Franchise owner Brian Macak, issued a statement that read: “Food quality is our top priority and drives every decision we make. The Department of Health inspected our store on Friday following a handful of complaints about one delivery, but they found no food hygiene issues at the store. Regardless, we voluntarily closed our store for a few hours yesterday afternoon to deep clean all of the equipment… The Department of Health is continuing its investigation and we are working closely with them to provide any information required.”

The Weston, Jimmy Johns is one of 2,500 locations in 46 states by the sandwich restaurant chains that specializes in delivery.  The chain was founded by Jimmy John Liautaud in 1983.  Based in Champaign, IL, 98 percent of its locations are owned by franchise holders.

Past food safety challenges for Jimmy Johns have focused mostly on its use of sprouts.