Legionella is in the water supply of our long term care facility

  1. Recently a resident of our long-term care facility was found to have Legionella pneumonia. Tests performed by the health department revealed that Legionella is in our water supply. Is Legionella often found in long-term care facilities?
  2. We have had 4 other cases of pneumonia in which urine antigen tests have been negative- however, two of these patients did not really improve clinically until they were put on Zithromax for their antibiotic therapy. I also raised the question of aspiration and was told this is not a problem, however you indicate that it is. Now, I am flushing the nasogastric tube of my patient with sterile water until we have treated our water supply
  3. He has already had documented aspiration pneumonia 2 times and is one of the patients that did not improve until Zithromax was given. If his urine antigen test was negative can we feel confident that he did not have Legionella?


  1. Yes. It is present in the drinking water of many long term care facilities. No formal survey has yet been performed – but 20-70% of hospitals harbor Legionella. In addition, numerous cases of Legionnaires’ disease have been reported from long-term care facilities and nursing homes (Fang GD, Med 90; Marrie TJ 86, Loeb M 99, Maesaki 92, Brennen C 87). We are now recommending that all such facilities culture their water supply ( Seenivasan M, Journal of American Geriatrics Society, 53:875-880, 2005).
  2. We agree with your approach. Aspiration has been shown to be a major mode of transmission for Legionnaires’ disease and studies in long-term care facilities show that aspiration occurring from nasogastric tubes, indeed, is a risk factor for aspiration (Loeb MJ 02, Am Geriatrics 99; Seenivasan M, in press).
  3. No. Although the sensitivity is about 85%-90% for Legionella pneumophila, serogroup 1, it will not detect other Legionella spp or serogroups. Azithromycin (Zithromax) is effective therapy. Levofloxacin (or another quinolone) might also be used empirically for nursing home pneumonia of uncertain etiology if the water supply harbors Legionella. Quinolones also cover other common pathogens in nursing home pneumonia including gram-negative rods.