Legionella has been found in our hospital and the water supply was successfully disinfected with copper-silver ionization. Nevertheless, showers for our transplant patients have been banned. This is a major inconvenience for patients and nursing staff. If, as you claim, aerosolization is not the mode of transmission, why should showers be banned? Our engineering staff also monitors showerheads by removing them and cleaning them with disinfectants although this is done on an erratic basis.
Showers are not important disseminators for Legionella. Our view has credibility since Dr. Victor L. Yu was a co-author of the article published in the Annals of Internal Medicine 1981 that suggested Legionella might be transmitted via showers. Subsequent case-control studies showed our original conclusion was erroneous, although no retraction has ever been published. Subsequent studies from Belgium, Netherlands , University of Virginia, Wadsworth VA Medical Center, University of Iowa, Lackland Air Force Base, University of Pittsburgh, and University of Arizona also showed this conclusion was erroneous. The article by Sabria in Lancet Infectious Disease 2002 gives an overview of the studies. Most (but not all) U.S. transplant centers have quietly rescinded their ban on showering and cases of Legionnaires’ disease attributed to showering have not occurred. We agree with this policy.
Studies also show that disinfection of showerheads by chemicals or cleaning is ineffective long term given the fact that Legionella recolonizes the showerheads from existing biofilms in the pipes of the plumbing system.