Dallas County Health and Human Services warned and advised people with weakened immune systems to avoid swimming in public pools or using water parks.

Dallas County has recorded 50 cases of cryptosporidiosis this year. In Collin County, just north of Dallas, 15 cases of cryptosporidiosis have been confirmed. Tarrant County has had 67 confirmed cases linked to Burger’s Lake.

Cryptosporidiosis is an intestinal illness caused by a microscopic parasite called Cryptosporidium. The disease can be spread through contaminated water, including swimming pools. It also spreads to people who drink water that has contaminated feces in it. Infected individuals can shed the organism in their stool for several weeks after they recover from the illness.

The most common symptoms of crypto are diarrhea, nausea, fever, stomach cramps and vomiting.

Approximately 400-500 cases are reported in New York State each year.

The Dallas County medical examiner’s office was conducting an autopsy to see if the death of 6-year-old Rosemary Stagaman on Monday was related to the parasite. Laboratory tests in her case could take at least six weeks to complete. The girl’s father told the Dallas Morning News that she did swim but that he did not know what led to her death. Rosemary Stagaman of Richardson died Monday at Medical City Dallas Hospital.

You can minimize the chances of acquiring and spreading the infection by thoroughly washing your hands, avoid drinking untreated and inadequately filtered surface water, avoid swallowing water when swimming, especially in lakes, ponds or rivers.