From Canada to Wales, if you’re racing mountain bikes, try not to swallow the mud – apparently there’s a lot of shit in mud.

In June 2007, hundreds were stricken and 18 tested positive for campylobacter during the annual Test of Metal mountain bike race in Squamish, B.C.

Dr. Paul Martiquet, the chief medical officer for Vancouver Coastal Health, said,

"This was an outbreak with a high attack rate. Our future advice to the race organizers is to inspect the route prior to the race to ensure it is not littered with animal feces, and not end the race at the horse ring. If there is any horse poop, they have to remove it."

Now, a preliminary report by the National Public Health Service for Wales estimates that up to 160 people who attended the Merida Bikes mountain bike Marathon July 5-6, 2008, based on Builth Wells, fell ill, and 10 of the riders tested positive for campylobacter.

The report described the course as,

“very muddy and contaminated with sheep slurry in certain areas, leading to significant amounts of mud splashing over participants and their equipment. … The most statistically significant risk was the inadvertent ingestion of mud. The nature of this sport means that riding through muddy, agricultural land is unavoidable. The risk of infection from zoonotic organisms such as campylobacter will therefore always be present. Clearly the weather conditions on the day of this event compounded the problem by making contamination by mud inevitable.”