Fern Leitman, 56, a longtime Florida resident, thought her repeated bouts of pneumonia were just bad luck. Doctors told Suzan King-Carr, 58, of Hobe Sound, Fla., that the spots on her lungs were probably cancer. Ida Mae Williams, 76, of Bogalusa, La., was informed that she had tuberculosis. Three women, three different diagnoses--all of them wrong. After years of ineffectual treatment, each woman learned that she, like thousands of other Americans, had developed a mysterious lung infection that mimics TB, seems to strike thin, white women in particular and can be permanently debilitating. Most unsettling of all, they could have developed the ailment simply by stepping into a shower.
Physicians don't know much about this mysterious illness. Like TB, it is triggered by a group of germs called mycobacteria. Unlike TB, it is not contagious, though it seems to thrive in hot, humid states in the U.S. Indeed, a recent survey conducted by health authorities in Florida found that hospitals in the region discharged far more patients with non-TB mycobacterial (or, as doctors call it, NTM) infections than with TB. And once you have NTM, it's tough to get rid of. "It takes three times as long to treat as conventional TB and relapses are common," says Dr. Michael Lauzardo, deputy TB controller of Florida. Drug costs alone run $5,000 a year, and a full course can last 18 months.
Not only does the number of cases appear to be growing, but the infection itself seems to be changing. Back in the 1950s NTM infections were rare, usually occurred in male smokers and were generally curable. In the 1980s NTM emerged as one of the opportunistic infections that AIDS patients developed after their immune system collapsed. (Combination-drug therapy has since produced a sharp drop in AIDS-related mycobacterial infections.) Now, the typical patient with a NTM infection is an otherwise healthy Caucasian woman who is usually middle aged and often thin.
What is unclear is whether the increase in reported cases is the result of better diagnoses or of some as yet undiscovered change in the bug or the environment it grows in. "That's what keeps me awake at night," says Dr. Gwen Huitt, a pulmonologist at the National Jewish Medical and Research Center in Denver. "These mycobacteria are everywhere." They thrive in what scientists call biofilms--pond scum and the slime inside faucets and showerheads.
Shower stalls are particularly suspect. Some doctors believe that mycobacteria from the pipes are becoming aerosolized in water spray. The more enclosed a shower stall, the greater the buildup of germ-infested spray. (A variant of the illness--sometimes called hot-tub lung--occurs when people develop an allergic reaction to the mycobacteria in indoor hot tubs.) Making matters worse, says Dr. Michael Iseman of National Jewish, "we have changed the way we treat our water." Since the 1970s, the temperature of most hot-water heaters has been reduced to 120[degrees] to save energy and prevent scalding--perfect conditions for mycobacteria. The result: we shower in a fine mist of mycobacteria that reaches deep into our lungs.