LEGIONNAIRES’ DISEASE

It made headlines in 1976, when it affected 221 people and caused 34 deaths during an American legion convention at a Philadelphia hotel. As perplexed health-care workers scrambled to combat this mysterious ailment that caused high fever, diarrhea, nausea, lung congestion and severe coughing, many wondered if an epidemic was about to sweep the country.

It didn’t happen. Instead, Legionnaires’ disease––a rare form of pneumonia––slowly faded from public awareness. But it didn’t disappear. The federal Centers for Disease Control (CDC) in Atlanta continue to receive reports about 1,000 cases a year. Fortunately, Legionnaires’ is easily treated with antibiotics and is seldom fatal when promptly treated.

Since the Philadelphia outbreak, researchers have linked Legionnaires’ to several mysterious epidemics dating back to 1965. They have also identified a platoon of at least 19 types of bacteria that can cause the disease. The bacteria collectively referred to as legionella bacteria, like water and have been found in lakes and streams and in man-made devices such as hot tubs, ice machines, faucets and hot water heaters.

This Legion Doesn’t March, It Swims

In the past, most outbreaks have been associated with hospitals and hotels. Most likely, that’s because some hospitals and hotels keep the hot water at temperatures lower than many people do in their homes. Unfortunately, Legionnaires’ bacteria thrive in those lower temperatures, says Victor Yu, M.D., chief of the Infections Diseases Section of the Veterans Administration Medical Center in Pittsburg. The bacteria have also been found in homes, however.

“There are a few people who get Legionnaires’ disease from contaminated water in their own homes,” Dr. Yu says. “How they get it is nuclear. Perhaps they get it by taking a shower and breathing in the aerosols. You can get it from a humidifier. A humidifier vaporizes the contaminated water, and you inhale it.”

If you do use a humidifier, there are a couple of simple steps you can take to protect yourself.

Clean and disinfect it at least once a week. Bleach and other disinfectants will kill any Legionnaires’ bacteria that may be lurking in the humidifier’s reservoir. Follow the manufacturer’s instructions, Dr. Yu says.

Use sterile water. “if you use tap water contaminated with Legionnaires’, the humidifier will send out a mist containing the organism, “ Dr. Yu says. “Sterile water will eliminate that possibility. Tap water can be sterilized by boiling.”

Cutting the Risk

Between 2 and 7 percent of al pneumonias are caused by Legionnaires’, says Barbara Marston, M.D., an epidemiologist at the CDC. Its symptoms are similar to those of other types of pneumonia and commonly include coughing up phlegm, chest pain, stomach cramps and fever, sometimes in excess of 1040F.

Untreated, Legionnaires’ may have up to a 25 percent morality rate. But proper treatment with the antibiotic drug erythromycin reduces the death rate to about 5 percent, says Richard Kohler, M.D., a professor of medicine specializing in infectious disease at Indiana University School of Medicine in Indianapolis. Two new drugs, clarithromycin and azithromycin, promise to be effective against the disease.

Smokers, heavy drinkers and people who have chronic respiratory diseases such as emphysema and bronchitis are most likely to get the disease. (So quitting smoking and drinking moderately, if at all, will also help reduce your risk.) Organ transplant recipients also are at high risk, because the drugs used to prevent rejection of the transplant by their body also suppress the part of the immune system that would normally fight off Legionnaires’, Dr. Marston says.

See a doctor immediately if you do get symptoms of Legionnaires’. “Recovery depends on the overall health of the patient,” says Marston, “But recovery is quite probable.”