Michigan health experts say a virus that sickened people who took part in a long-distance race through mud and other obstacles likely originated from a participant on the course.
The grueling 'Tough Mudder' obstacle course included more than 22,000 participants and spectators at the Michigan International Speedway June 29-30. But after the hardcore competition at least 200 people reported flu-like symptoms that lasted for several days.
Now the state Department of Community Health says the norovirus that made people sick likely originated from a participant on the course. Health officials say most illnesses were reported from people who had mud or muddy water in the mouth.
The state says race officials are working to prevent health problems in the future.