about two dozen people have come down sick after eating at a Subway restaurant in Idaho. Public health officials say the pathogen is norovirus.

The Southwest District Health department reports “nearly 25” people have reported gastrointestinal illnesses since Friday, March 19. The outbreak investigation is ongoing.

Canyon County restaurant inspection reports are not available online for public viewing.

“The Subway involved is working cooperatively with SWDH following suspected presence of norovirus and instituted mitigation measures to halt the spread of the virus. Following the inspection by SWDH, it was determined that the facility was following all guidance and recommendations,” according to a notice posted by the Southwest District Health department.

The implicated restaurant is on 10th Avenue in Caldwell, ID, which is in Canyon County. Health officials say that so far “there is a strong link” between the restaurant and the sick people. The patients reported eating food purchased at the Subway from March 16 through 19.

Anyone who believes they may have been exposed is asked to contact public health officials at 208-455-5442.

Symptoms of norovirus infection include vomiting and diarrhea, which can be severe. Symptoms usually begin within two days of exposure to the virus. The infections can lead to dehydration. Patients, especially elderly people and young children, may need to seek treatment to rehydrate.