The Billings Gazette is reporting that at least 17 people have become ill with Shigellosis in Fremont County, Wyoming. Health officials have not determined the source of the outbreak, but are concerned that infected individuals are now passing the infection from person to person.

“‘It doesn’t appear that there’s any large common source of food or water’ causing the infections, said Dr. Tracy Murphy, the Wyoming state epidemiologist. ‘It’s being spread now through one infected person through another.’

Shigellosis is caused by the shigella sonnei bacterium, which occurs in fecal matter. It can cause abdominal cramping, loose or bloody stools and fever. It can be fatal in severe cases, although that’s uncommon.

Murphy said anyone who thinks they might be infected should avoid going to school or work and should see a doctor.”