Fighting fires is hazardous duty, but for 20 Indiana and Michigan firefighters an unexpected risk was being sickened by Cryptosporidium.

Their story is told in the Centers for Disease Control and Prevention March 9 edition of the Morbidity and Mortality Weekly Report.

On June 6, 2011, the CDC recounts, a fire broke out in a Michigan calf barn about 15 miles from the Michigan-Indiana border. Thirty-four firefighters from three Michigan and one Indiana fire stations responded, helping to lead about 240 week-old calves to safety. Water from a local hydrant and a nearby pond was used in extinguishing the blaze.

Within 12 days of the fire, 20 of the firefighters had suffered diarrhea, abdominal cramps, nausea, vomiting and fever. Most missed work and one required hospitalization – he had to have his gallbladder removed.

Cryptosporidium parvum was identified in patient stool specimens, and outbreak investigators later found Crypto organisms at the farm in calf fecal samples and the pond.

Most of the firefighters who were sick had rescued calves from the barn; a few had some exposure to the pond water. The firefighter who was hospitalized probably had the greatest exposure — he had fallen into a manure pit while rescuing calves.

One of the most frequent causes of waterborne disease in the U.S., Cryptosporidium is a microscopic parasite. While the diarrheal disease is called cryptosporidiosis, both the parasite and the illness are often referred to as “Crypto.”

Food Safety News has reported cases of cryptosporidiosis from raw milk sold in Minnesota and from swimming pools

According to the authors of the CDC report, the findings from the calf barn fire outbreak not only “highlight a novel work-related disease exposure for firefighters,” but also the need for public education regarding cryptosporidiosis prevention.

They note that most health-care providers don’t request Cryptosporidium testing regularly, and routine laboratory testing of stool specimens typically does not include Cryptosporidium.

And they add that the actual number of firefighters infected in the calf-barn fire outbreak might have been larger than reported, because some people infected with Cryptosporidium are asymptomatic.

To prevent similar outbreaks, the CDC makes several recommendations:

– adequate drinking water during firefighting responses and decontamination of firefighting equipment


– firefighters should only consume treated or bottled water, or sports drinks

– equipment and clothing should be decontaminated at the scene whenever possible, especially if contaminated with feces, to reduce transmission of Cryptosporidium, Giardia and other zoonotic enteric pathogens (e.g., E. coli, Salmonella and Campylobacter)

– clothing contaminated with feces should be machine-washed and heat-dried on the highest clothes dryer heat setting for 30 minutes whenever possible

– non-machine-washable items and equipment should be cleaned with soap and water to remove fecal contamination, air-dried, and left in the sun for at least 4 hours after drying. For equipment that cannot be cleaned with soap and water or equipment that contacts the mouth (e.g., respirator pieces), soaking in 3% hydrogen peroxide solution for 20 minutes is recommended after consulting manufacturer guidelines