Cases of intestinal illness spike in Yellowstone County

(RiverStone Health Press Release)

BILLINGS - RiverStone Health public health officials are investigating an outbreak of Cryptosporidiosis (Crypto) in Yellowstone County from multiple water sources.

Crypto is a diarrhea-causing illness caused by the protozoan Cryptosporidium. It is most often spread when a person swallows water containing germs from the fecal matter of infected humans or animals. Transmission is typically from swimming pools, as the organism is highly resistant to chlorine, as well as open water like lakes and rivers.

So far this summer, public health officials have identified 26 confirmed cases of Crypto, as well as 29 additional cases linked to the confirmed cases. In 2023, there were nine confirmed cases, and four confirmed cases in 2022.

Once a person is infected, the incubation period averages seven days but can range up to 12 days.

Signs and symptoms include diarrhea (often profuse and watery) and sometimes vomiting. Diarrhea may wax and wane, but commonly stops in otherwise healthy individuals within 30 days.

The best way to prevent the spread of Crypto is to not swim while having diarrhea, or for two weeks after symptoms have ended. Other prevention strategies include:

• Avoid swallowing water while swimming.
• Ensure that small children wear watertight swim diapers.
• Wash your hands with soap and water after swimming or playing in the sand to avoid infecting food and surfaces (Alcohol-based sanitizers are not effective against Crypto).
• Shower before swimming.

The last time public health officials investigated a Crypto outbreak in Yellowstone County was a total of 23 confirmed and probable cases in August-September 2013.
For more information about Crypto, go to cdc.gov/cryptosporidium [cdc.gov] .