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Water Bug Invasion: Keeping Legionella at Bay

Created Sep 14 2015, 08:00 PM by Lippincott Solutions
  • pneumonia
  • Legionella
  • Pontiac fever
  • OSHA
  • outbreak
  • fever
  • infectious disease
  • respiratory infection
  • legionellosis

Tuesday, September 15, 2015

It’s been a busy end-of-summer for infectious disease practitioners. The Legionella bacteria have been wreaking havoc, causing respiratory infections in a variety of locations throughout the United States.  First, an outbreak of Legionnaires’ disease was reported in the Bronx, New York City. According to the New York City Department of Health and Mental Hygiene, 124 people were infected with the bacteria at a hotel in South Bronx, New York, leaving 12 people dead. Next the Illinois Department of Public Health announced 52 cases of Legionnaires’ disease at the Veteran’s Home in Quincy, Illinois; 7people were reported dead. The California Department of Corrections and Rehabilitation reported 6 confirmed cases of Legionnaire’s disease among inmates from San Quentin State Prison; so far there have been no confirmed deaths…overall, some pretty frightening statistics.

Outbreak potential

So what constitutes an outbreak? Outbreaks of Legionella occur when two or more people become sickened by the bacteria at about the same, in the same place, such as in a healthcare facility. Healthcare facilities have complex water systems and many people who become infected have preexisting conditions that make them susceptible to Legionella infection.

Other confirmed outbreaks have been linked to aerosol sources in the community, onboard cruise ships, and in hotels. In these locations the most common sources are hot tubs, air-conditioning cooling towers, hot water tanks, large plumbing systems, decorative fountains, and water used for drinking and showering.

Breaking out

So what causes the disease to break out? Fortunately, the bacteria don’t spread from person-to-person. Instead, they spread when people breathe in small droplets of water (mist or vapor) in the air that contain the bacteria. For example, a person may become infected from inhaling droplets sprayed from a hot tub that hasn’t been properly cleaned and disinfected, or by inhaling droplets while taking a shower in a hotel with a contaminated hot water tank. It makes you think twice about relaxing in a hot tub or taking a nice, hot hotel shower.

Pontiac fever vs. Legionnaires’ disease

The good news is most people who are exposed to the Legionella bacteria don’t become sick. Some may develop a milder infection, known as Pontiac fever. Signs and symptoms of Pontiac fever are similar to Legionnaires’ disease, but the patient doesn’t develop pneumonia. Pontiac fever usually resolves in 2 to 5 days and doesn’t require treatment.

Signs and symptoms associated with Legionnaires’ disease commonly appear 2 to 10 days (can occur up to 2 weeks) after exposure to the bacteria and include:

  • Cough
  • Headache
  • High fever
  • Muscle aches
  • Shortness of breath.

How is Legionnaires’ disease diagnosed?

Pneumonia, associated with Legionnaires’ disease, is typically confirmed by clinical examination or chest X-ray.  Urine antigen assay testing is used to detect the presence of the Legionella bacteria. Legionella bacteria can also be identified through a culture specimen obtained from sputum, a lung biopsy specimen, or various other sites.

Protecting your facility from a Legionella invasion

So how can you protect your facility from this deadly invader? Make sure the water system is properly monitored and maintained to prevent the buildup of scale and sediment. Refer to the Occupational Safety & Health Administration’s Technical Manual on Legionnaires’ Disease for details. Recommendations that appear in the technical manual include:

  • Storing hot water at 140 °F (60 °C) and delivering it at a minimum of 122 °F (50 °C).
  • Periodically increasing the water temperature to at least 158 °F (70 °C) or using chlorination followed by system flushing if the building can’t be retrofitted.
  • Inspecting systems annually to make sure equipment functions properly.
  • Maintaining cold water below 68 ° F (20 °C).
  • Eliminating cold water tanks that allow water to remain uncirculated for extended periods of time.
  • Covering cold water tanks to protect them from extreme temperatures.
  • Preventing cross-contamination of the domestic cold water system with other systems.
  • Using hyperchlorination to eliminate Legionella if found in cold-water lines.
  • Cleaning and disinfecting cooling towers at least twice a year.

Do you know if your facility is taking these measures to prevent an outbreak of Legionnaires’ disease?  Has your facility ever experienced a Legionnaires’ disease outbreak? If so, what lessons have you learned that may benefit others?

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