The U.S. Centers for Disease Control and Prevention (CDC) confirmed that 22 individuals that got sick in October 2012 had gotten sick as a result of being exposed to bacteria after a muddy obstacle course race.  After three active duty military personnel presented at their Air Force base emergency department with fever, vomiting, and bloody diarrhea, public health officials were notified.  Another 19 individuals, both civilian and military, were then identified with similar symptoms.

Officials confirmed that they had a Campylobacter coli infection that was likely the result of falling face first into mud, having their heads submerged into surface water, or accidentally ingesting muddy water.  After conducting a controlled study, the CDC is encouraging race organizers and public health agencies to inform attendees of the hazards related to ingesting muddy water by accident.

According to KWTX, the race that sparked this outbreak was a Tough Mudder, but similar races carry the same threat of infection.  Adventure races in the U.S. attract about 1.5 million participants annually.  Men’s Fitness reports that these obstacles are popular with a variety of people, especially those seeking a thrill.  One of the newest obstacles include a “human pyramid,” which uses a chain of arms and legs from contestants working together to get over a 12-foot high slanted wall.

Still, new obstacles present the same risks of infection as old ones.  In fact, this year Tough Mudder has introduced “Vesuvius,” a two-story high slide with a wall of fire that lands in a pool of cold mud and water.  It would be difficult for participants to not go completely underwater, increasing the risk for accidentally ingesting some murky water.

MedlinePlus reports that Campylobacter is a common source of intestinal infection.  It is one of the common sources of food poisoning and traveler’s diarrhea.  Most often, an infection comes from contaminated food or water, raw poultry, fresh produce, or unpasteurized milk.  However, it is also possible for an infected person or animal to pass it onto another person or animal.