Efficacy of new point-of-use water filter for preventing exposure to Legionella and waterborne bacteria.
BACKGROUND
Legionella species cause health care-acquired infections in which immunocompromised patients are disproportionately affected. Epidemiologic studies have demonstrated that point-of-use water fixtures are the reservoirs for these infections. The current approach to prevention is system-wide chemical disinfection of the hospital water system. These methods affect both low-risk and high-risk areas. A more effective approach to prevention may be a targeted approach aimed at protecting high-risk patients. One option is the application of a physical barrier (filter) at the point-of-use water fixture.


OBJECTIVE
To evaluate the ability of point-of-use filters to eliminate Legionella and other pathogens from water.


METHODS
One hundred twenty-milliliter hot water samples were collected from 7 faucets (4 with filters and 3 without) immediately and after a 1-minute flush. Samples were collected every 2 or 3 days for 1 week. This cycle was repeated for 12 weeks. Samples were cultured for Legionella, total heterotrophic plate count (HPC) bacteria, and Mycobacterium species.


RESULTS
Five hundred ninety-four samples were collected over 12 cycles. No Legionella or Mycobacterium were isolated from the faucets with filters between T = 0 and T = 8 days. The mean concentration of L pneumophila and Mycobacterium from the control faucets was 104.5 CFU/mL and 0.44 CFU/mL, respectively. The filters achieved a greater than 99% reduction in HPC bacteria in the immediate and postflush samples.


CONCLUSIONS
Point-of-use filters completely eliminated L pneumophila and Mycobacterium from hot water samples. These filter units could prevent exposure of high-risk patients to waterborne pathogens.
Sheffer
Patricia J
PJ
VA Pittsburgh Health Care System, Pittsburgh, Pennsylvania, USA.
Stout
Janet E
JE
Wagener
Marilyn M
MM
Muder
Robert R
RR
D000704:Analysis of Variance; D003428:Cross Infection / Q000517:prevention & control*; D004203:Disinfection; D005374:Filtration / Q000295:instrumentation*; D006761:Hospitals; D006801:Humans; D007876:Legionellosis / Q000517:prevention & control*; D009165:Mycobacterium Infections, Nontuberculous / Q000517:prevention & control*; D014871:Water Microbiology