Battling Bacteria

Legionnaires’ disease has hospitalized, and in some cases killed, nearly 100 travelers in the United States, Spain, and Canada already this year. The disease is a form of pneumonia that stems from legionella bacteria growth in commercial water systems, including those found in hotels and hospitals.

Symptoms of Legionnaire’s disease, which generally develop two to 14 days after exposure to legionella bacteria, include headaches, fever, chills, coughing, shortness of breath, and chest pain. Risk of contracting the disease is greater for people age 50 and older or those with preexisting health conditions such as diabetes, cancer, lung disease, and kidney failure. The Center for Disease Control (CDC) explains that cases of Legionnaires’ disease have been on the rise since 2003, with 4,155 cases of legionellosis reported in 2011, an increase over the number of cases reported in 2010.

In August, Legionnaire’s disease caused three deaths at the JW Marriott Hotel in Chicago, and another three individuals died after contracting the disease from the Diamante Beach Hotel in Calpe, Spain in January. The Diamante Beach Hotel was closed for an investigation this summer after health officials discovered a second outbreak, which was linked to 25 confirmed cases of the disease. Last week, a report linked at least one case of Legionnaires’ disease to a Comfort Suites in Grantville, Penn. In Quebec, the death toll recently reached 13, after an outbreak, allegedly stemming from high-rise cooling towers, hit the city beginning in July.


Hotels, specifically those that have hot tubs, whirlpool baths, steam rooms, decorative fountains, and cooling towers, are susceptible to the growth of legionella bacteria. If the bacteria is found, hotel heath clubs and spas can be closed for days for cleaning and treatment, or hotels with severe cases can potentially be shut down for a week or more to comply with investigations by local health departments. If not maintained properly, these hotel systems can put the safety of guests and employees in jeopardy. Legionnaires’ disease linked to hotels can also result in expensive lawsuits against the property.

The CDC states that 3,000-4,000 cases of Legionnaires’ disease are reported in the United States every year. However, that number is likely much less than the number of people actually infected with the disease.

“Many cases of Legionnaires’ disease are never diagnosed or reported to public health,” says Laurel Garrison, an epidemiologist at the CDC. “We estimate that many more people actually get it and don’t even know.”

“Legionella is a bacteria that grows naturally in fresh water, but it really only becomes a problem in man-made environments,” says Garrison. “The conditions that legionella requires to grow are warm water, stagnant water, and water that has low or no levels of chlorine or disinfectant.”

Garrison states that the sources linked to Legionnaires’ disease must also contain a mechanism for aerosolization, a process in which liquid particles are suspended in gas. Breathing in mist or vapor infected with levels of legionella bacteria is the most common way to contract Legionnaire’s disease. The disease is not spread through person-to-person contact.

In order for hotels to prevent the growth of legionella, Garrison explains properties must be diligent in maintaining hot tubs, cooling systems, hot-water heaters, and fountains.

“Hotels should make sure that temperatures and disinfectant levels are what they should be, and there should be routine monitoring of those levels,” she says. “There should also be routine shocking and cleaning treatments in hot tubs and pools, as well as filter cleaning and replacement.”

For cooling towers, which usually deliver air-conditioning to guestrooms and public areas, the CDC recommends that hotels work with professionals to make sure the systems are maintained and working properly, and that start-up and shut-down procedures are being followed correctly. The agency also encourages hotels to regularly monitor hot water heaters to make sure they are storing water at a high enough temperature to prevent legionella growth. If legionella stems from a hot water heater, it could potentially be delivered to guests via in-room showers or faucets.

Garrison says that maintenance of decorative fountains and water features should be similar to the treatment of pools and hot tubs, with regular shock treatments and continual monitoring. Hotel owners and managers often overlook fountains as potential sources for legionella colonization. The JW Marriott in Chicago uninstalled the fountain in its lobby after linking the structure to this summer’s fatal outbreak.

“Even small fountains that don’t produce a lot of spray can be a source,” says Garrison.

If legionella is detected during maintenance checks, Garrison explains that commercial heat treatments or extreme chlorination can kill the bacteria. If the bacteria is discovered, Garrison recommends getting to the origin of the problem as quickly as possible to prevent future complications.

“There needs to be a long-term plan for addressing the reason why the bacteria was colonized in the first place,” she says. “Addressing the root cause of the issue is important.”

For hotels wanting more details on proper maintenance procedures and preventive measures for protecting their properties against legionella growth, the CDC recommends consulting guidelines published by the American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE). Details relating specifically to minimizing the risk of legionellosis associated with building water systems can be found in the ASHRAE Guideline 12-2000. ASHRAE is also developing another Standard (Standard 188), which will expand on preventing Legionnaires’ disease in commercial properties. Standard 188 has gone through its second public review and will be available to hotel owners and managers in the near future.