Cryptosporidiosis: Local pool-related cases revealed

The recent spread of cryptosporidiosis, also known as “crypto,” has been in the news. The microscopic parasite can circulate in swimming pools and water parks and recently caused illnesses linked to pools at a Chula Vista resort.

The resort, known for what it calls a “4-acre water park oasis,” was forced to temporarily close its pools, perform a hyperchlorination treatment to eliminate the parasite, and notify guests who visited between July 24 and Aug. 15. Weeks later, County health inspectors cleared all its pools, spas and water park features to reopen.

According to Dr. George Sakoulas, an infectious disease doctor with Sharp Rees-Stealy Medical Group and affiliated with Sharp Memorial Hospital, he’s not surprised to learn of the parasite’s spread in a region with more than 4,000 public and semi-public pools. “It's happened before, typically at water parks, water slides and kiddie pools.”

Understanding cryptosporidiosis

Cryptosporidiosis is an infection caused by the parasite Cryptosporidium. According to the Centers for Disease Control and Prevention (CDC), the parasite infects the intestines and can cause diarrhea and other gastrointestinal symptoms.

Cryptosporidium is spread through fecal-oral transmission. This means you become infected by accidentally swallowing the parasite after it enters your mouth from contaminated waste (poop), objects, food or water.

Why crypto concerns health officials

Unlike many germs that are quickly killed by pool disinfectants, crypto can survive in chlorinated pool water for days.

“The challenge with this particular organism is that it's chlorine-resistant,” Dr. Sakoulas says. “Normally, we think of chlorine killing organisms. This one can survive a week to 10 days in a chlorinated pool.”

Because only a small number of parasites are needed to cause infection, outbreaks can occur when someone who is ill enters a pool and contaminates the water.

County health officials advise that people who visited the affected pools, water slides or lazy rivers during the exposure period may have been at risk.

The symptoms to watch for

The CDC reports that symptoms of cryptosporidiosis usually begin two to 10 days after exposure and can last up to two weeks or longer.

The most common symptom is watery diarrhea. Other symptoms may include:

• Stomach cramps or pain

• Nausea

• Vomiting

• Fever

• Dehydration

• Loss of appetite

• Weight loss

Some people infected with crypto have no symptoms. However, they can still spread the parasite.

Although most healthy people will recover, Dr. Sakoulas says prolonged diarrhea can lead to dehydration. For many people, treatment focuses on preventing dehydration by drinking plenty of fluids. Rest is also essential to recovery.

Individuals with weakened immune systems, young children and older adults may be at greater risk for serious illness. Rarely, some may require medication.

Preventing crypto

While reports of the pool-related crypto outbreak may be concerning, experts say understanding how to prevent infection can help keep you and your family safe.

Preventing cryptosporidiosis starts with good hygiene and responsible pool habits. “We always tell people that if they’ve had a diarrheal illness, they must not go into a public swimming pool or water park for about two weeks,” Dr. Sakoulas says.

The CDC also recommends:

• Avoid swallowing pool, splash pad, lake or ocean water.

• Wash your hands thoroughly with soap and water after using the restroom and before eating.

• Do not swim if you have diarrhea.

• Keep children with diarrhea out of pools and water play areas.

• Take children on frequent bathroom breaks and check diapers often.

• Wash fruits and vegetables before eating.

If you’re wondering whether it's safe to return to a pool after a crypto-related closure — specifically the one at the South Bay resort — Dr. Sakoulas offers reassurance. Because the pools at the resort have been extensively cleaned and disinfected, “it's most likely the cleanest they will ever be,” he says.

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