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Legionnaire's disease

Legionellosis is an infection caused by species of the bacterium Legionella, most notably L. pneumophila. At least 46 species and 70 serogroups have been identified. L. pneumophila, a ubiquitous aquatic organism that thrives in warm environments (25 to 45 °C with an optimum around 35 °C) causes over 90 % of Legionnaires Disease. more...

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The disease has two distinct forms:

  • Legionnaires' disease is the name for the more severe form of infection which includes pneumonia
  • Pontiac fever is a milder respiratory illness without pneumonia caused by the same bacterium

Legionnaires' disease acquired its name in 1976 when an outbreak of pneumonia occurred among persons attending a convention of the American Legion in Philadelphia. Later, the bacterium causing the illness was named Legionella.

On January 18, 1977 scientists identified a previously unknown bacterium as the cause of the mysterious "Legionnaires' disease."

An estimated 8,000 to 18,000 people get Legionnaires' disease in the United States each year. Some people can be infected with the Legionella bacterium and have mild symptoms or no illness at all.

Outbreaks of Legionnaires' disease receive significant media attention. However, this disease usually occurs as a single, isolated case not associated with any recognized outbreak. When outbreaks do occur, they are usually recognized in the summer and early fall, but cases may occur year-round. About 5% to 30% of people who have Legionnaires' disease die.


Patients with Legionnaires' disease usually have fever, chills, and a cough, which may be dry or may produce sputum. Some patients also have muscle aches, headache, tiredness, loss of appetite, and, occasionally, diarrhea. Laboratory tests may show that these patients' kidneys are not functioning properly. Chest X-rays often show pneumonia. It is difficult to distinguish Legionnaires' disease from other types of pneumonia by symptoms alone; other tests are required for diagnosis.

Persons with Pontiac fever experience fever and muscle aches and do not have pneumonia. They generally recover in 2 to 5 days without treatment.

The time between the patient's exposure to the bacterium and the onset of illness for Legionnaires' disease is 2 to 10 days; for Pontiac fever, it is shorter, generally a few hours to 2 days.


Intestinal Infections: These may only occur as part of respiratory infections, where gastrointestinal symptoms have on occasion been described.

Extraintestinal Infections: L. pneumophila is specifically considered as a pathogen of the respiratory tract, where it is a cause of atypical pneumonia, also known as Legionnaires' disease. Other infections have also been reported, including haemodialysis fistulae, pericarditis and wound and skin infections. Bacteraemia is often associated with Legionnaires' disease.

One species Legionella Longbeachae is contracted via inhaling infected compost or soil.


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Bugs in the workplace: from mold to asbestos to Legionnaires' disease to hepatitis, infectious diseases lurk within the work environment. Have you done
From Risk & Insurance, 8/1/02 by Lori Widmer

In 1976, a mysterious disease broke out among conventioneers at the American Legion conference in Philadelphia. What was not known then is that a bacteria that causes a serious form of pneumonia can harbor in air conditioning and cooling systems. Public health officials now know that Legionnaires disease is contracted by inhaling the mist of water contaminated with the bacteria.

Even with regulations now in place to help protect ventilation systems, workers still face the risk of infection. In June of this year in a Philadelphia suburb, Legionnaires' reappeared in a nursing home, killing two patients and sickening 10 others, including one employee of the nursing home. A similar outbreak, where one employee died, occurred at a Ford Motor Co. plant in Cleveland in March 2001.

Legionnaires', however, is not the only contagion that lurks in the workplace. Airborne bacteria, asbestos, molds, or chemicals that show up in packages, even anthrax in the mail make the workplace a minefield of contagions that threaten employees'--and a company's--health and well-being.

The result of an infectious outbreak could be a staggering hit to the workers' compensation claims area, as well as a company's bottom line. A report by the RAND Institute for Civil Justice estimated that asbestos lawsuits are clogging the courts, despite the fact that asbestos has not been in wide use for close to 30 years. More than 600,000 cases have been filed to date and the group estimates that there is a potential for 500,000 to 2.4 million similar claims. The cost to businesses to date is well over $200 billion, and additional suits could cost $145 billion to $210 billion.

Even secondhand smoke is a liability. Consider the June 2002 $5.5 million jury award in a Miami case in which a former flight attendant sued four major tobacco companies, claiming her working conditions caused chronic sinus problems. She claimed that the smoky airline cabins, caused by the defendants' product, are responsible for her illness.

Even if your company is smoke-free or has no contact with chemicals or chemical processing, there are still hidden dangers that could send your work force into quarantine.

Common Contagions

First, while the threat of bioterrorism is valid, to the experts, it's a remote one. "We don't know how much more we're going to see, obviously," says Natalie Firestone, VP of health care risk management at Near North National Group, Chicago. "But if you're including everything (in an evaluation of risk), then you have to look at the bacteria and fungi from bioterrorism, the things terrorists might use--cholera, pneumonic plague, smallpox, etc."

In addition, mold is on top of everyone's complaint list these days, says Louise Vallee, environmental health manager for Chubb Corp., Warren, N.J. Under the mold umbrella is legionella, the bacteria that causes Legionnaire's disease. "Mold is related to water intrusion," she says. "A risk manager can start by asking questions about water intrusion: Do we have leaks? Any incidents of flooding? Are we by a river? Any mildew smells? If that building is nice and dry, it's highly unlikely that mold is going to be there."

According to the Centers for Disease Control (CDC) in Atlanta, an estimated 8,000 to 18,000 Legionnaires' disease in the United States each year. The disease is responsible for up to 30 percent of pneumonia-related deaths each year. While industries with coolant systems seem to have a higher prevalence of Legionnaires' disease, the bacteria has been found in a wide range of locations, from nursing homes and hospitals to manufacturing plants and government office buildings.

As for asbestos, there is good news. "Asbestos is probably less prevalent now because of the various abatement efforts over the years," says Howard Klein, partner at Conrad O'Brien Gellman & Rohn, a Philadelphia-based litigation firm. Klein is inclined to believe that once residual asbestos issues are cleared from the courts, there will be a sharp decline in the suits filed in the future. He believes that mold will drive the majority of litigation, replacing asbestos suits.

Hepatitis Risk

"What's on the rise would be hepatitis B and C infections," says Firestone. "We're going to see hepatitis B cases lowered because people are beginning to be vaccinated. To me, people are more concerned with hepatitis C because they don't know much about it."

Hepatitis C is a viral infection that causes chronic liver disease. In a study conducted between 1988 and 1994, the Third National Health and Nutrition Examination Survey revealed that 3.9 million people in the U.S. are infected with hepatitis C. While the disease is prevalent among health care workers, it can be spread through direct contact with infected blood. Although the risk is low, even people working in prisons, construction workers, volunteers, and day care workers are at risk, Firestone says.

Contracting hepatitis C can be quite easy, Firestone says. "If there is dried blood on surfaces, the hepatitis virus can remain intact for up to one week." Treating hepatitis C, however, is more difficult. There is no vaccine, and the current treatment, interferon, has severe side effects.

Firestone believes that a lack of education has led to a misunderstanding about the risk associated with hepatitis C.

And this misunderstanding has created gaps in coverage for some workers. Hepatitis C has not always been recognized as a work-related illness. In one notable case, a Philadelphia Fire Department paramedic was denied workers' compensation benefits because she couldn't prove that her hepatitis was contracted while on the job. Mary Kohler camped outside the city mayor's office for 15 days to protest the city's handling of hepatitis C cases. Her actions resulted in Pennsylvania Governor Mark Schweiker signing legislation in December 2001 that allowed paramedics and police officers in the state who contract the disease to file for workers' compensation.

Evaluation and Prevention

Employers need to be proactive in addressing the risk of contagions, says Firestone.

But providing a safe environment can be a challenge, especially if the employees are alarmed and worried about conditions. "What happens today is that many employees continue to be concerned about the safety and health of their workplace," says Vallee. "That is not always founded on fact. Sometimes it's a fear. Whether it's real or not, companies have to address those concerns. As complaints and symptoms arise, it's important to address them right away."

To ignore issues is to hurt the bottom line, says Klein. "Any employer should provide a safe workplace. From a legal perspective if they don't, they're going to be subjected to workers' compensation liability and the like. Whatever the cost is, it's going to be less than having your business close down."

Firestone agrees. "All businesses will someday be affected by this issue. You're going to have a decline in productivity, high absenteeism, some people will lose the skills, and there will be a disruption in service. Then you have the cost of recruitment and training if you need to replace someone, as well the cost to provide workers' comp coverage for the employee who has the illness."

Promoting prevention, she says, starts with educating employees and managers. Companies should consider hiring health care workers, infection control practitioners, or public health workers to train the work force, she recommends. Other recommendations include developing policies and procedures for infectious disease and airborne disease threats.

Employers also need to be aware of possible hidden exposures. For one thing, foreign-born employees may pose a risk of passing infectious diseases to other workers since they may not be vaccinated or not vaccinated according to the U.S. schedule. For example, cases of tuberculosis, a highly contagious bacterial infection of the lungs that is spread through the air, is more common among people in the United States who were born outside this country than among those born within the U.S., according to a recent report by the CDC.

But there are solutions available for determining risks related to workplace contagions. "Turn to the insurance companies, the loss-control departments, or to outside consultants," says Vallee. "In some states, the state department of labor offers free assistance. What's key is listening to the complaints, sorting them out, determining which ones can be handled by the company given their existing knowledge base, and for which ones they need to turn to outside assistance."

Determining the need for proper help is easy, says Vallee. "If a company doesn't have an existing industrial safety or hygiene staff, they would want to turn to a safety or industrial hygiene surveyor. A survey could mean asking questions, walking around the facility, observing the operation, looking at control measures, then possibly following up with air samples."

Firestone recommends developing an education program that addresses a possible crisis. "You want to be proactive rather than reactive to a crisis situation. Help prevent discrimination by increasing awareness. Establish workplace policies on what to do if someone is exposed to infectious disease. Start out with management and leadership training, then on down to the employee component of education."

Privacy Issues

With person-to-person contagion, one critical issue is privacy. Companies are required to protect the privacy of the employee when it comes to disclosing a workplace hazard such as tuberculosis or hepatitis.

"You have to be very cognizant of not invading someone's confidentiality about their personal illnesses," says Klein.

The reason: "You need to do your monitoring and assessments with an eye toward not causing panic. You don't want to create a workplace panic by how you conduct an evaluation."

Vallee says its important to seek the advice of professional investigators when testing for infectious diseases to help protect employee privacy and to navigate the extensive regulatory requirements for testing. The Occupational Safety and Health Administration (OSHA), she says, has many requirements for testing for both blood-borne pathogens, such as hepatitis, and airborne hazards, such as Legionnaire's disease.

Keeping information confidential also is a requirement of the Americans with Disabilities Act, which says that any information collected is to be maintained on separate forms in separate files, away from the employee's personnel record and is to be treated with the same degree of privacy as a medical record. Supervisors may be informed of an employee's condition only if there are necessary work restrictions being requested.

"There's a lot of stigma attached to infectious disease," Firestone says.

Lori Widmer can be reached at

COPYRIGHT 2002 Axon Group
COPYRIGHT 2002 Gale Group

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