A diarrhea-inducing parasite that typically thrives in swimming pools is on the rise in El Paso County so far this year.

Fewer than a dozen people have been sickened, but 11 is a four-fold increase over the three sickened last year. Just two were sickened the year before.

The spike in cases of cryptosporidiosis this year is not from any outbreaks, said Dr. Bernadette Albanese, medical director at The El Paso County Department of Health and Environment. Exactly what’s driving the trend, however, is unknown. Cases have been on the rise nationally, she said. Reasons could include better testing, more frequent testing, or just more of the disease.

The bug affects the gastrointestinal system and leads to diarrhea, abdominal cramping and discomfort. Most people recover from the disease without treatment.

Crypto is largely resistant to chlorine, so it can thrive even in a well-maintained pool.

The best prevention is to shower before swimming and for parents to ensure children don’t swim if dealing with a bout of diarrhea.

Although cases are higher this year in the county, the opposite is true for Colorado. The state had 217 cases of crypto in 2007, 113 last year, and 61 so far this year.

Call Newsome at 636-0198. Visit the Pikes Peak Health blog at www.pikespeakhealth.freedomblogging.com and the Gazette’s Health page at Gazette.com/health