Legionnaire’s Disease & Your Plumbing

You may have seen the news last month when an outbreak of Legionnaire’s disease in New York killed seven people and sickened more than 80 others. It was one of the biggest outbreaks of Legionnaire’s in recent times.

The disease got its name when it was first identified from an outbreak at an American Legion convention in Philadelphia in 1976 that killed a bunch of attendees, most of them elderly veterans of World War II and the Korean War. Its symptoms resemble that of pneumonia, and it is spread by Legionella bacteria that thrive in warm mists from stagnant water in plumbing and HVAC systems. Last month’s New York City outbreak was traced to a cooling tower that was part of the air conditioning system in a commercial building where the victims got exposed. The disease also can be spread via hot tubs and sometimes showerheads and faucets.

The Centers for Disease Control (CDC) says that about 4,600 cases of Legionnaire’s are reported each year in the U.S., resulting in about 2,400 deaths. The high percentage of deaths is somewhat misleading. The CDC estimates that between 8,000 and 18,000 people are sickened by Legionnaire’s each year, including cases that likely go unreported or misdiagnosed. The disease can be treated with antibiotics. When properly diagnosed and treated, the death rate goes down to around 5%.

How worried should you be about contracting Legionnaire’s from your household plumbing system?

Not very. All of those deaths and illnesses are tragic, but the numbers are relatively small in a population of more than 300 million. By comparison, about 35,000 people a year lose their lives and hundreds of thousands get injured in auto accidents.

Researchers have discovered that Legionella bacteria are quite common in our environment. Most of us have probably been exposed to them at some point without getting sick. The threat is greatest to people with weakened immune systems. The elderly and people with HIV or other ailments are most susceptible. According to the CDC, most deaths from Legionnaire’s disease are tied to hospital and nursing home showers. Moreover, the disease is not contagious from person to person. You can only get it by direct exposure to the Legionella bacteria.

If you own a hot tub, it’s important to treat the water with recommended disinfectants. As for household showerheads and faucets, there’s not a lot of preventive maintenance you can do. Temperatures above 140 degrees will kill the bacteria, but that is scalding temperature and creates even bigger problems. If you use your showers and faucets daily that will likely eliminate the stagnation that provides a hospitable environment for the Legionella bacteria.

If you are away for a length of time, you may want to run your shower and faucet for a few seconds to get rid of the stagnant water inside the pipes. (You may look at that as a waste of water amid our drought, but if you’re worried about Legionella it will bring peace of mind.) If you are very concerned, investigate a household water treatment system using copper-silver ionization, which has been shown to kill the Legionella organism. This is especially advisable if you have senior citizens living at home.

Bottom line: It’s never wrong to take precautions, but Legionella ranks pretty low on your list of household dangers.