GLENWOOD SPRINGS, Colo. (CBS4) – Health officials are investigating after four people became sick after visiting the Glenwood Hot Springs Resort pool. Since mid-August, there have been four confirmed cases of cryptosporidiosis, which is caused by a microscopic parasite.

Glenwood Hot Springs Resort

Glenwood Hot Springs Resort (credit: CBS)

Officials say cryptosporidium is one of the most common illnesses caused by germs spread through pool water in the United States. Symptoms usually last one to two weeks and include diarrhea, abdominal pain/cramps, nausea, vomiting, fever, and weight loss.

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Garfield County Public Health is now working to contain the spread of illness by interviewing cases, identifying symptomatic contacts and providing prevention education. Officials add that the resort has taken all measures to stop the spread of the parasite.

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According to officials, chlorine levels during the time of concern were within the appropriate regulatory range. However, the parasite can be resistant to concentrations of chlorine and other disinfectants.

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For more information about cryptosporidiosis, visit the CDC website.