Frequently Asked Questions from the General Public 

 

 I have personally been infected by Legionnaires’ disease. What can I do to increase awareness of this infection so that others could be spared this terrible disease?

       The most important problem that we face as physician researchers in this field is that a startling amount of misinformation is present and scientifically validated information that would allow prevention of this infection is not disseminated by public health authorities. It is a fact that Legionella is commonly found in the drinking water supply of large buildings. 

       Since the discovery of the source of the organism in 1982 (Stout, N Engl J Med 1982), this important fact has not been exploited for prevention.  Most public health authorities are not interested because of the panic and media exposure that it may bring.  Likewise, hospitals are afraid of negative publicity, overlooking the fact that if patients learn that they contracted the infection from being admitted into a hospital that did not check their water supply for Legionella that they would not only sue, but they would win. 

       The one thing that you can do if you have contracted Legionella from a hospital is to ask the following question.  Did the hospital have a preexisting policy to culture the water supply?  This approach is recommended by state health departments of Maryland and Allegheny Health Department (Pittsburgh).  However, Denmark, France, and Barcelona, Spain have also established guidelines for hospitals to culture their water supplies.  In 2003, after much foot-dragging, the CDC recommended that all hospitals performing bone marrow and solid organ transplants should culture their water supply.  Unfortunately, many cases occur in non-transplant patients.  Regardless, we feel that all hospitals should culture their water supplies.  CDC has argued in the past that it’s expensive, but culture material, including formulation of the Pittsburgh media, is now commercially available, and the cost for materials is probably less than $500 a year.  Nevertheless, they have balked at this recommendation.

          Hundreds of outbreaks from hospitals have been reported.   Nosocomial (Greek for hospital-acquired) Legionnaires’ disease is now commonplace and has become a well known complication. 

          Approaches for preventing any patients from contracting the disease within a hospital have been published by the State of Maryland and Allegheny County (Pittsburgh) Health Departments. Both health departments recommend that the hospital water supply be cultured for Legionella.  If Legionella is found, the physicians are informed so that if the patient contacts pneumonia while in the hospital, tests for Legionella should be immediately available in-hospital.  This is a matter of common sense.  Moreover, if many of the water sites are positive (for example, greater than 30%), the hospitals can disinfect their water supply.  Copper-silver ionization is now the most widely used modality and there are a number of reputable manufacturers for such devices.

          Inexplicably, a major obstacle to this approach is the Centers for Disease Control in Atlanta, Georgia, which has been very slow in moving forward on this issue.  In 1993, CDC guidelines actually discouraged hospitals from performing routine environmental cultures.  They claimed that the evidence was insufficient despite that fact that several hundred reports had documented that Legionella could be contracted from hospitals including their own investigations.  One of their reasons (which has been convincingly refuted) is that since the organism is ubiquitous, it could exist in hospitals without harming the patients (Yu VL.  Resolving the controversy on environmental cultures of legionella.  Infect Control Hosp Epidemiol, 1998).  We and others now have presented data to show that as many as 70% of hospitals. In some cities harbor Legionella (in San Antonio, the number is 100%); this information is critical to disseminate to physicians in the affected hospitals.  

          In summary, the current approach throughout the world, with some exceptions, is to ignore the problem altogether. 

 

My 5 year friend got leukemia and is now in maintenance chemotherapy phase.  Do you have any data about the effects of Legionella on such patients?   What the best way to avoid the infection?

        With the exception of hairy cell leukemia which has a disturbingly high incidence of Legionnaires' disease, leukemia is not a major risk for Legionnaires’ disease except for the time they spend in hospitals.  The greatest risk comes from hospitals that have Legionella in the hospital drinking water, but are unaware or do not want to be informed of its presence.  A few hospitals test their water supply for Legionella, and their patients are safe.  Unfortunately, most do not.  The CDC now recommends that hospitals in which bone marrow transplants are performed should culture their water supply.  We recommend that immunosuppressed individuals not drink tap water, but water that has been sterilized by boiling and then cooled.
 

Can Legionnaires' be ingested and give symptoms of nausea and vomiting and migrate to the lungs via the digestive route?

        Your scenario above is not quite correct, but close. Click onto General Information and there is some discussion on Aspiration. Nausea, vomiting, diarrhea can occur. The Legionella bacterium, enters the lung not through the digestive tract, but is aspirated through the windpipe (trachea).
 

The building I work in has tested positive for Legionella bacteria.  One individual fell sick last week.  What are the risks to me if I keep showing up for work and inhaling the air conditioned air?  Do you think I should leave?  Some hot spots were found in the building...two in air conditioning water cooler towers and one in a ladies bathroom sink one floor beneath me. An outside Legionella risk management company came in to the building to conduct independent testing and found no Legionella bacteria present in the water supply.  Then, the City Health Department then conducted their tests;  Legionella was present and potent.  Is there still a risk if the building has been cleaned?  Can you please give some direction.  No one is telling us anything.

        It is not well-known to the public that Legionella in large building water supplies is commonplace.  The fact that Legionella was found in the workplace water systems of a sick person does not necessarily mean that this was the source of infection.  If the Legionella organism was isolated from the patient, molecular typing can be done on both this organism and the Legionella recovered from the water systems.  If they match, then there is a stronger probability that the workplace was the source.
       The reason for not being overly concerned is that unless you have an immunosuppressive underlying illness or smoke cigarettes, you are at little, if any risk.  Healthy individuals have many potential sources for exposure to Legionella in the community, as well as from home water systems. Although we understand your concern, no guidelines on workplaces or public buildings have been formulated because the risk is so low.

 

The health department in our state has discovered that my husband's place of employment has the Legionella bacteria in their water.  Should he be tested to see if he is infected? 

        No.  Individuals who are not susceptible hosts (e.g., cigarette smokers, transplant recipients) are not at high risk for Legionnaires’ disease. If your husband has signs of pneumonia (high fever, cough), then he should consult his physician for a chest x-ray.  If he seems healthy, testing is unnecessary for your husband.

 

We moved into a new building 4 months ago, a 2 level office building with under floor ventilation (air conditioning).  Over the Christmas period one of the pipes broke and leaked approximately 1 foot in areas of water into the under floor system (approx 2 foot deep) where all of our electrics were running along with the air conditioning system, which continues to blow cool air.  The building must be half a quarter of mile long if not more and the whole of the underground floor was flooded in various depths.  The maintenance men have continued to pump out the water for 2 days and regain electrical connections, but the water may have been sitting there for a period of up to two weeks. Should the water be tested for Legionella?

        We would not be concerned about the risk for Legionnaires' disease in the situation that you describe. We believe that aspiration is the major mode of transmission, not aerosolization (See General Information on the Home Page for a fuller explanation). Regardless, the risk is very low for either mode of transmission.

 

I have read recently that home hot water pipes may be a breeding ground for Legionella. Is there any kind of filtration system for the home that would solve this or is boiling the only remedy?

        You may want to read the paper on our web site “Legionnaires' disease contracted from patient homes.” Unless you are at increased risk of contracting Legionnaires' disease (chronic lung disease, immunosuppression, transplant recipient), you are at such a low risk of becoming infected that there is no need for any action on your part. For individuals at high risk, we recommended increasing the hot water temperature to approximately 60oC (140oF) max. setting on the hot water tank and flushing the outlets for 30 min. with the hot water. This can be done on a quarterly to annual basis to reduce the level of Legionella within the system. However, this procedure is unnecessary for most homes.  There is a risk of scalding with water at this temperature, so caution must be exercised if elderly or small children use the water.

       Filtration would be expensive because the filter would have to remove particles the size of bacteria (0.2 microns) and they would have to be changed frequently.

 

I had new piping put in my house and the plumbers didn't do the job right.  Mold formed inside the house in three of the bedrooms and I became sick with pneumonia.  It was later diagnosed as Legionnaires’ disease.  Can Legionnaries’ disease be caused by mold? Or affect the air conditioner in my house where the spores would be spread around the house?

        Legionella can be contracted, not by mold, but by the water in your home water distribution system.  Your doctor is required to report your case to the Health Department, perhaps, they may culture your drinking water for Legionella.  If you live in Pennsylvania, Ohio, and New York, these Health Departments will do this free for you in collaboration with our laboratory.  Although air conditioning is popularly thought to be linked to Legionnaires’ disease in the original 1976 American Legion outbreak, it is now known the source may have actually been the hotel water distribution system. The role of air conditioners in disseminating Legionnaires’ disease is not supported by scientific studies. 
 

Is there any data about contracting Legionella from swimming pools especially if they have not been used all winter long?  

        The risk from contracting Legionnaires’ disease from swimming pools is negligible. 
 

I have been asked to clean bathroom tiles and shower heads in a chain of hotels. Will dry steam cleaning machines kill this bacteria?  Would ordinary steam cleaning machines kill this bacteria?

       Heat above 170oF and drying will kill Legionella.   However, bathroom tiles, even when wet, will not transmit Legionella. So you need not worry about Legionella in that situation.

 

What are the chances of getting Legionella from open system of hydronic radiant heat where you get your house heating and drinking water from the same source?

       The risk from hydronic heating is unknown, but we know of no cases of Legionnaires’ disease from such sources.  However, as the article on our Home Page shows, one can contract Legionella from home water distribution systems and large building water systems.  But the risk is extremely low and close to zero if you are not a cigarette smoker.  And, if you were a smoker, I would quit smoking and not worry about the hydronic heat.

 

Is it common for a person to have a blood test positive for Legionella without a history of illness?  Is there any reason for concern for future illness?

          The blood test (antibody serology) is most accurate when a person is ill with pneumonia.  If the person has no pneumonia and does not have an abnormal chest x-ray, this person may have encountered Legionella many years ago and is ok now.

          Based on our studies, we suspect that presence of antibody may be protective, since we never encountered patients who have contracted Legionnaires' disease twice. 

 

My goldfish died last week.  I thought I overfed it.  But, an outbreak of Legionnaires’ disease occurred at a large aquarium in our country (Australia). Could my fish have died of Legionnaires’ disease?

          We think you overfed the goldfish.

 

My husband has been diagnosed with Legionnaires’ disease, but has no underlying risk factors that we know of.  He was cured with erythromycin.  He is 38 years old.  Should we be concerned about his immune system and should his doctor be looking for reasons that he contracted this?

         The answer may be yes, since it is unusual for nonsmokers to contract Legionnaires’ disease.  Did he stay at a hotel or other large building in the 10 days before symptoms?

 

His case has been reported to the local Health Dept. and they conducted a phone interview, but they won't be doing anything to determine where he was exposed. 

         They should try to locate the source.  If you live in Maryland, New York, Ohio, or Pittsburgh, these Health Departments are more experienced with Legionella investigations. 

       Minor point:  Erythromycin is effective, but azithromycin is more potent, has fewer side-effects, and can be given once daily for a shorter duration.  It also is more expensive.  Levofloxacin is also highly potent.  Your doctor should be congratulated for making the diagnosis.

 

The Health Dept. did conduct a limited phone survey, but did not come to the house for an inspection.  We have been advised that I probably inhaled or aspirated some standing water.  After 3 weeks, I am back to work, but my strength and stamina are low.  We are trying to determine the source of the Legionella so we can take corrective action.

 I would appreciate your thoughts regarding the two likely sources in our home:

 1.  A portable air conditioner that has a 1/2 liter reservoir to catch the condensate.  The instructions say to pour this accumulated water down the drain whenever it gets full, which is about once a week during normal use in the summer.  One week before I got sick, I began to clean this air conditioner and noticed the reservoir had developed a pink mold.  I poured out a small amount of water into the sink.  I then began to vacuum and clean the insides of the air conditioner, so I could put it away and store it for next summer...

2.  I use a dental night guard every night; it is a formed plastic mold of my teeth that keep me from grinding my teeth.  I store it in a glass of water every day, and sometimes I forget to change that glass of water for a week or more.  Maybe I pulled the night guard out of the "dirty" water and went to bed.  Sometimes I cough after putting it in my mouth, and maybe some of the water went down the "wrong pipe" and got into my lungs (aspiration). How could I get this air conditioner tested?  Right now I'm afraid to use it and we spent $500 on it.  I don't want to throw it away and I wouldn't sell it if I thought it was dangerous. Also, can you provide any information on how to properly disinfect this air conditioner and would you think it is safe to use again?

       The air conditioner is not the likely source.

       The dental night guard soaked in tap water may be the source.  This can be proven by culturing the home water supply and the "dirty water."  If the health dept will not provide this service, we can do it gratis if the Legionella has been isolated from culture of your sputum.  Otherwise, merely use boiled water for storing your dental guard.  Let it cool before dropping your dental mold into it.

 

Has the Legionnaire's disease and its media coverage had any adverse social impact like did AIDS in the first few years of its discovery and then was understood better?

          The impact of the lay media has been both positive and negative.

          Negative: Bad publicity to a hospital or organization can result because the primary source is the drinking water;  cooling towers or air conditioners are overemphasized by the authorities since the public is more alarmed by drinking water sources than by localized sources such as cooling towers.  The truth can bring panic and a flurry of lawsuits.

          So, hospitals often do not want to know about Legionella in their drinking water.  Nor do public health agencies want to push this issue because of the inflammatory nature of the truth.  On the other hand, we believe that knowledge about the hospital drinking water can allow preventive measures to be taken by the hospital and alerting the MDs such that the disease can be prevented or treated earlier.

          Positive:  Revelations by the lay media have stimulated many hospitals to take preventive measures. The best example is the 1998 TV exposè by New York City Fox news.  Their reporters went into NYC hospitals and cultured legionella from the drinking water of most hospitals. Unbeknownst to the TV reporters is that in one hospital that was culture-negative in their report, Legionnaires’ disease had been discovered in the patients and the hospital water supply was the source.

 

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