Thursday, January 15, 2009

Legionnaires' Disease

What's Behind the Steep Rise In Legionnaires' Disease Infection

Perhaps you remember back to the American bicentennial celebration in July 1976, when thousands of members of the American Legion arrived to celebrate in Philadelphia, whereupon hundreds got sick and 34 people died from the severe lung infection that came to be known as Legionnaires' disease. It is a form of pneumonia contracted by inhaling Legionella bacteria, which thrive in warm water found in plumbing systems, whirlpool spas, cooling towers and showers.
Lately there has been a steep rise in the number of cases, according to figures released by the Centers for Disease Control and Prevention. According to Lauri Hicks, MD, a CDC medical epidemiologist, between 8,000 and 18,000 people are hospitalized with Legionnaires' disease in the US each year, with the number of reported cases up 70% between 2002 and 2003.

The reason for the increase remains unclear -- Dr. Hicks speculates it might relate to climate conditions that enable the bacteria that cause the disease to thrive, or it might be that diagnosis and reporting have improved. Even so, she said she believes that the disease remains both under-diagnosed and under-reported.

Legionnaire's Disease: A Primer

Legionnaires' disease resembles other forms of pneumonia, with symptoms such as high fever, chills, coughing, muscle aches and headaches appearing two to 14 days after exposure to the bacteria. It's a serious illness, causing death in 5% to 30% of cases. Older people, smokers, people with chronic lung disease and those with weakened immune systems are particularly susceptible to infection and at greatest risk of complications. A milder form of the disease is known as Pontiac Fever -- collectively, Legionnaires' disease and Pontiac Fever are often referred to as legionellosis.

Legionella bacteria enter the body via inhalation of contaminated water droplets in the air -- for example, through air conditioning systems in large buildings or whirlpool spas that have not been properly cleaned and disinfected. Another source of infection is by drinking contaminated water. Treatment is with antibiotics.

Large-scale environments such as hotels or ships or hospitals are most likely to have Legionella lurking somewhere in their systems, but the bacteria can also be found in apartment building and hotel cooling towers... garden ponds and fountains... hot water heaters... and sometimes even in freshwater ponds and creeks. Dr. Hicks advises people at greatest risk to take precautions to limit exposure, especially when traveling or in a medical facility. Her advice includes...

Limit exposure to public whirlpool spas. Studies have shown that these are one of the prime culprits in Legionnaires' disease.

Beware of long, hot, steamy showers -- especially in big buildings, such as apartments or hotels, which are more likely to harbor Legionella bacteria. The best defense is to make sure that water heaters bring temperatures above 140ºF.

Follow a healthful lifestyle. A robust immune system is your best protection against Legionnaires' as well as other diseases.

If you are immune-compromised and therefore especially vulnerable to such infections, talk to your healthcare provider about how to avoid infection. This is one more illness you don't need to get.

Source(s): Laurie Hicks, Respiratory Diseases Branch, The Centers for Disease Control and Prevention, Atlanta, Georgia.

No comments:

Post a Comment

You are not entitled to your opinion. You are entitled to your informed opinion. No one is entitled to be ignorant.

Harlan Ellison