Medicine

Parasites lurk even in well-chlorinated pools

Showers help prevent spread of disease

By Kathleen McLaughlin, The Bulletin

Property manager Jim Elliott easily remembered the last time he dealt with a “brown-out” in the Cascade Village swimming pool.

One of the residents of the 55-and-older community stood in the water, holding a baby in a diaper: “There’s brown all around him. He’s oblivious,” Elliott said.

When it comes to spreading disease at public pools, the release of diarrhea is a worst-case scenario. The parasitic protozoa Cryptosporidium, or Crypto, can live for several days in a properly chlorinated pool. Ingesting just a little contaminated water could make one sick for weeks with watery diarrhea and cramps.

While many large aquatic facilities use ultraviolet radiation to kill what chlorine can’t, most hotels and neighborhood pools don’t have UV equipment. So it’s up to the maintenance staff and swimmers themselves to prevent illness.

“People need to understand that chlorine doesn’t kill germs instantly,” said John Mason, the public health specialist who oversees public and communal pools for Deschutes County Health Services. Most of the pools that he inspects are at apartment complexes and neighborhoods where the maintenance staff has duties other than checking chlorine and pH levels in the pool every four hours.

Their jobs are made more difficult, Mason said, by the fact that many swimmers don’t bother to shower first. During a recent inspection, Mason gave Cascade Village kudos for installing a new shower in the bathhouse. On-deck showers aren’t required in Oregon, but Mason thinks they go a long way toward encouraging the habit. Showering removes dead skin, dirt and oils that take up chlorine molecules that should be killing harmful germs, he said.

Mason doesn’t sample pools for microorganisms. Instead he checks the water chemistry, pump and filtration system and maintenance logs. “We’re hoping the chlorine, and the pH, and the operator’s knowledge are going to protect the public’s health.”

Crypto and another parasitic protozoa, Giardia, are both present in feces, which is why kids in diapers are such a threat. Children attending large day care facilities are common carriers of Crypto, but their parents might not be aware. A 2011 University of Michigan study, cited by the Centers for Disease Control, found that most parents of young children don’t place a high priority on showering before swimming.

Western states including Utah and Colorado saw large outbreaks of Crypto-related illness in 2007. The number of cases in Oregon also rose that year to more than four per 100,000 people and continues to remain above the national average, according to the Oregon Health Authority. The OHA notes that the rise in reported cases could be attributable to better testing.

Deschutes County has been fortunate in avoiding cryptosporidiosis. There has been no more than one case per 100,000 people from 2003 to 2014, according to the Oregon Health Authority.

Giardia, however, is much more common in Deschutes County, which saw 14.5 to 19.5 cases of giardiasis per 100,000 people in the same time frame.

As with Crypto, the Giardia parasite can live in chlorinated water and causes chronic diarrhea. Young children in day care, as well as hikers drinking untreated water, are at the greatest risk.

Mason wouldn’t go so far as to ban tots from public pools, but he said their parents should be vigilant. “Diapers, even swim diapers, tend to act like a sieve,” he said. “They keep the big chunks in, but there’s still water washing in and out of that diaper.”

So, Mason urges parents to wash their babies’ bottoms, and check diapers every 30 minutes. Area public pools require plastic pants over diapers.

After the incident at Cascade Village more than five years ago, Elliott said he drained the pool and scrubbed the walls.

“We’d rather have you hyper-chlorinate the pool,” Mason said. Then he whipped out the CDC’s protocol on responding to fetal accidents, which is subtitled: “What do you do when you find poop in the pool?”

The CDC has different guidelines for accidents involving diarrhea versus formed stool, which is less of a threat to public health. Because it’s associated with Crypto, a diarrhea release requires closing the pool and keeping chlorine at 20 parts per million for close to 13 hours.

To get an idea of Crypto’s imperviousness, consider that water chlorinated at 1 part per million can kill E. coli in less than a minute. The same water would take more than 10 days to kill Crypto.

Mason, a former fisheries biologist, spends much of his time during inspections teaching basic chemistry and helping pool operators stay in compliance.

A strong odor of chlorine is not a good sign, Mason said. The smell means there’s not enough chlorine in the water to kill germs. Instead, the chlorine is combining with dirt but not breaking it down. The off-gassing is akin to a smoky campfire, he said.

“He works with me, is what I like,” Gary Pomeroy, engineering supervisor at the Red Lion Hotel on NE Third Street in Bend. “I’ve learned a lot from him.”

Mason’s surprise inspection at the Red Lion fell on July 7, the Tuesday after a busy Fourth of July weekend. Walking up to the pool, Pomeroy explained that he was fighting green algae and bad chlorine.

Mason congratulated Pomeroy for catching the algae early and gave him some advice for getting the pool chemistry back to normal.

“I think he got overwhelmed with bathers this past weekend,” Mason said.

Swimmers who want to make sure they’re using a clean pool should ask how many times a day chlorine and pH levels are checked, Mason said. “If they check once in the morning, once in the evening, that’s probably not a very well-maintained pool.”

Public pools, including Juniper Swim and Fitness in Bend and SHARC aquatic park in Sunriver, are required to employ certified pool operators and check chemistry at least every four hours.

Brown-outs are a regular event in the kiddie pool at Juniper Swim & Fitness Center, Assistant Manager Sarah Romish said. “We had an incident last week,” she said. The pool was closed for half an hour, per CDC guidelines.

“I’m always surprised that people want to get right back in after it’s been closed,” Romish said. “I think people have great trust in us.”

— Reporter: kmclaughlin@bendbulletin.com, 541-617-7860.

Tips for staying healthy around pools:

• Don’t swim if you’ve had diarrhea in the last two weeks

• Shower first

• Check your baby’s diaper at least every half hour

• Don’t swallow pool water

• Ask how often pool chemistry is checked

10398746
This image is copyrighted.