Nontuberculosis Mycobacteria Sometimes Transmitted Through Hot Tubs, Indoor Swimming Pools

DENVER -- A healthy, middle-aged man falls sick after breathing the mist produced by an indoor hot tub. A healthy, middle-aged woman contracts a mysterious lung disease after regularly swimming laps in her indoor pool. Other than having indoor water features, they have nothing in common.

This isn’t an episode of the television program, The X-Files. For many people, these bacteria surface not as a plot device, but as a very serious health threat. At National Jewish Medical and Research Center, doctors have been treating more and more people with a lung disease called nontuberculosis mycobacteria (NTM).

Regular exposure to certain NTM—mycobacterium avium and mycobacterium chelonae are particularly rapidly-growing and pervasive strains—that thrive in a floating “slime layer” found in hot water heaters, and indoor pools, waterfalls and hot tubs can cause lung disease. Although most patients with NTM have no history of indoor hot tub or pool use, National Jewish doctors are aware that these environments may predispose people to these infections. “Once infected, it is very difficult to completely get rid of the infection,” says Charles Peloquin, Pharm.D., director of Pharmacokinetics at National Jewish and a researcher exploring the effectiveness of new drugs to treat the disease. “It’s very, very tough.”

Treatment of mycobacterium avium and mycobacterium chelonae is difficult. Effective treatment requires three to four antibiotics given at once, sometimes intravenously. In some cases, physicians are forced to surgically remove a portion of a patient’s lung to stop the disease.

Not only tough to treat, NTM can be a danger in hot tubs, indoor pools or waterfalls that haven’t been used in some time. The bacteria thrive in the pipes and standing water. “They can lay dormant and when put in the right environment can wake up again,” says Gwen Huitt, M.D., a National Jewish physician who treats people with the lung disease.

Mycobacteria avium is one of a group of NTM found in the environment and the most prevalent kind throughout the United States. (Southeastern states have more than double the number of cases reported than any other region in the county.) Unlike tuberculosis, transmitted from infected humans, NTM is contracted through water and soil, and is not contagious. In nature, these organisms live in brackish ocean water, like tide pools.

But indoor waterfalls, hot tubs or swimming pools—all of which produce a substantial mist—are causing this lung disease to become more prevalent. “These organisms are water-loving bugs,” Dr. Peloquin says. These organisms enter the air when a mist, called aerosolization, is produced and the bacteria are suspended in water droplets.

“You circulate this high quantity of bacteria and then people breath it in,” Dr. Huitt adds. “The bacteria are suspended in these vapor droplets and then family in other rooms may inhale them.”

Turning a faucet is probably the easiest way to be exposed. “If you turn on your shower you can aerosolize these organisms,” he says. Adding, “If you’re healthy it may mean nothing to be exposed to the bacteria. But if you already have lung disease you may have a greater chance of becoming infected with an NTM.”

For people infected with either organism, symptoms include fever, tiredness, night sweats, cough and weight loss. NTM is increasingly found among Caucasian women with no history of smoking. “These women tend to be thin, tall and middle-aged or older,” Dr. Peloquin says.

For more information on this topic or related topics, call LUNG LINE, (800) 222-LUNG, e-mail, lungline@njc.org or visit, http://www.nationaljewish.org/pa.

NOTE: Of the more than 40 known types of NTM, mycobacteria avium is the most common throughout the United States. Overall, the highest incidence of NTM is found in the southeastern United States, according to a 1999 report issued by the Centers for Disease Control and Prevention.