Number of confirmed cases of parasitic infection continues to rise;  public health officials say immune-compromised residents should stay away from public pools, water parks, lakes and rivers

An outbreak of Cryptosporidiosis in North Texas has prompted health department officials in both Dallas and Tarrant counties to warn HIV-positive people and others with weakened immune systems to stay away from public swimming pools and water parks.

Jacqueline Bell, public information officer with Dallas County Health and Human Services, and Al Roy, public information officer with Tarrant County Public Health, said that drinking water in both counties has not been affected by the outbreak.

DCHHS has also issued “strong recommendations” to the general public, as well as recommendations to public and private pool owners to try and curb the outbreak. (See list on page 20 for recommendations.)

Cryptosporidium is a parasite that occurs naturally and is most often spread through contaminated water. It is, according to the Centers for Disease Control, one of the most common water-borne diseases in this country.

When ingested, the parasite causes an illness, commonly called Crypto, marked by watery diarrhea and abdominal cramping.

It is treated with anti-diarrheal medicines, including the FDA-approved anti-protozoal drug nitazoxanide. Most people with healthy immune systems can usually recover without medication, according to information at the CDC’s Web site, and the symptoms are usually gone in about a week or two.


But the situation can be very different for those with HIV and other diseases that weaken the immune system.

While Crypto is, at the least, uncomfortable for an otherwise healthy person, for someone with a compromised immune system, including those with HIV, it can be deadly.

“Immunocompromised individuals are particularly at high risk for severe persisting illness from infection and may not respond to treatment with nitazoxanide,” according to a health advisory issued Aug. 1 by DCHHS. “Given the markedly increased rate of Cryptosporidium infections noted in Dallas County recently, DCHHS is recommending that immune-suppressed persons refrain from swimming in public pools or recreational water parks at this time.”

Normally, Bell said, DCHHS will see about 10 cases of Crypto a month during the summer. However, since June 28 of this year, officials have had 121 lab-confirmed cases of the parasitic infection, Bell said.

(The number goes up daily: 103 was the total number as of Wednesday afternoon, Aug. 6, up from 87 as of Tuesday afternoon, Aug. 5.)

Bell said many of the Dallas County cases could probably be traced to an outbreak at Burger’s Lake, a swimming hole on the west side of Fort Worth.

According to Roy, 67 cases have been linked so far to Burger’s Lake. Another 21 cases with no apparent connection to that lake have been reported, he said.

“We don’t know if someone may have gotten crypto at Burger’s Lake and spread it somewhere else, or if someone got it somewhere else and spread it there,” Roy said.

Roy said that increased media attention on the outbreak has probably contributed to the higher-than-usual number of reported cases. “Usually, when someone has the symptoms, they just medicate. Even if they go to their doctor, the doctor doesn’t usually test for crypto,” he said.

Bell said the slumping economy, higher gas prices and the above-normal temperatures also have probably played a role in the outbreak.

Most people are vacationing closer to home this year to save money, she said, and more area residents seem to be flocking to local pools, water parks, lakes and rivers to escape the scorching heat, she said. And people looking for variety in their weekend getaways are likely to visit different facilities, so they could contract Crypto at one location and then spread it to another, she said.

There have been reports that a 6-year-old child has died in Dallas County due to Cryptosporidiosis. But Bell said Tuesday, Aug. 5 that the medical examiner has not yet determined a cause of death in that case and that she could not comment on it.

Although Cryptosporidium is chlorine-resistant, Bell said a process called hyperchlorination can kill the parasite, and both Bell and Roy said that public pools and water parks in their areas have been hyperchlorinated.

Bell said that DCHHS had also contacted hotels, motels and apartment complexes and encouraged them to hyperchlorinate their pools also.

Roy said similar measures have been taken in Tarrant County, noting that the owners of Burger’s Lake have done “everything the CDC recommends to make their place safe.”

Although Burger’s Lake did close down July 16, a call to the facility on Tuesday, Aug. 5 confirmed that it is open for business again.

Both Bell and Roy encouraged even healthy people taking to the water this summer to “play it safe” to avoid infection. The biggest rule, they said, is, “Don’t swallow the water.”

And, Bell added, “Any time you have any kind of diarrheal or gastro-intestinal disease, refrain from going to any shared water facility for at least two weeks after the symptoms end.”

For more information on Cryptosporidiosis infection, go online to the CDC’s Web site at www.cdc.gov/crypto.

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DCHHS recommendations for preventing Crypto
For the general public:
• Anyone who has had diarrhea should not use water parks or pools while experiencing symptoms, and for at least two weeks after the symptoms have stopped.
• Do not let children sit on or drink from the water spouts in interactive spray water parks or pools.
• Shower before and after using water parks and pools.
• Wash your hands with soap and water after using the toilet or changing diapers.
• Do not take pets into pools and spray parks.
• Persons at high risk of developing severe illness, such as those with compromised immune systems, should avoid use of water parks or pools until further notice.
For pool owners and operators:
• Post signs regarding the above recommendations for the general public at your facility.
• All water parks and pools, both public and private, should hyperchlorinate immediately and consider preventive routine hyperchlorination on a weekly basis thereafter.
• Home owners should strongly consider hyperchlorination if their pool has been used by anyone who has had diarrhea. As a preventive measure, homeowners may also consider hyperchlorination if their pools are routinely used by persons who also use other water parks, spray parks, or pools.

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This article appeared in the Dallas Voice print edition August 8, 2008.