LONG-TERM EFFICACY OF HOSPITAL WATER NETWORK DISINFECTION BY MONOCHLORAMINE ON LEGIONELLA AND OTHER WATERBORNE BACTERIA Author/s: Beatrice CASINI1, Michele TOTARO1, Paola VALENTINI1, Janet STOUT2, Gaetano PRIVITERA1. Organisation or Affiliation: 1 Department of Translational Research, N.T.M.S., University of Pisa, Italy. 2 Special Pathogens Laboratory, Pittsburgh, PA, USA. Backgroung: The choice of an appropriate disinfection method represents a determining factor for reducing water-associated infections in healthcare setting. Objectives: Describe the long-term efficacy of an experimental monochloramine-based (MC) disinfection operated on the hot water loop of the Emergency Department (ED), a 112-bed ward of a teaching hospital. Methods: Starting from December 2010, on a monthly basis, Legionella and nontuberculous Mycobacteria (NTM) cultures were obtained on 126 water and 121 biofilm samples collected from the faucets of six distal and proximal sites from the MC generator device (Sanipur s.r.l., Italy) Findings and Conclusions: Before MC disinfection, in all 6 sites water and biofilm resulted positive for Legionella pneumophila ST 269 (mean count 7.2x103 CFU/L), while 3 resulted positive for NTM only in water (mean count 40 CFU/L). An hyper-chlorination shock and super-flushing were performed. Subsequently MC was regulated to 1.5 ppm and Legionella was not found in the next 30 months, except in two instances as a consequence of the device failure (100% positive sites, 8.8x104 CFU/L mean count). Legionella was recovered only in 15% (18/121) of biofilms, always associated with positive waters. An increased log density of viable Mycobacterium gordonae was detected in 5 on 6 sites, with 53% (29/55) of positive biofilms. Following the increase of MC to 2.5 ppm, NTM cultivability was no more regain from 42 water samples and only one biofilm resulted positive (1/42). Monochloramine resulted very effective although needed to be finely adjusted to get satisfactory results in the control of Legionella as well as other waterborne pathogens.
LONG-TERM EFFECTS OF MONOCHLORAMINE DISINFECTION FOR LEGIONELLA AND OTHER WATERBORNE BACTERIA CONTROL IN A HOSPITAL WATER NETWORK.
CASINI, BEATRICE;VALENTINI, PAOLA;BAGGIANI, ANGELO;PRIVITERA, GAETANO PIERPAOLO
2013-01-01
Abstract
LONG-TERM EFFICACY OF HOSPITAL WATER NETWORK DISINFECTION BY MONOCHLORAMINE ON LEGIONELLA AND OTHER WATERBORNE BACTERIA Author/s: Beatrice CASINI1, Michele TOTARO1, Paola VALENTINI1, Janet STOUT2, Gaetano PRIVITERA1. Organisation or Affiliation: 1 Department of Translational Research, N.T.M.S., University of Pisa, Italy. 2 Special Pathogens Laboratory, Pittsburgh, PA, USA. Backgroung: The choice of an appropriate disinfection method represents a determining factor for reducing water-associated infections in healthcare setting. Objectives: Describe the long-term efficacy of an experimental monochloramine-based (MC) disinfection operated on the hot water loop of the Emergency Department (ED), a 112-bed ward of a teaching hospital. Methods: Starting from December 2010, on a monthly basis, Legionella and nontuberculous Mycobacteria (NTM) cultures were obtained on 126 water and 121 biofilm samples collected from the faucets of six distal and proximal sites from the MC generator device (Sanipur s.r.l., Italy) Findings and Conclusions: Before MC disinfection, in all 6 sites water and biofilm resulted positive for Legionella pneumophila ST 269 (mean count 7.2x103 CFU/L), while 3 resulted positive for NTM only in water (mean count 40 CFU/L). An hyper-chlorination shock and super-flushing were performed. Subsequently MC was regulated to 1.5 ppm and Legionella was not found in the next 30 months, except in two instances as a consequence of the device failure (100% positive sites, 8.8x104 CFU/L mean count). Legionella was recovered only in 15% (18/121) of biofilms, always associated with positive waters. An increased log density of viable Mycobacterium gordonae was detected in 5 on 6 sites, with 53% (29/55) of positive biofilms. Following the increase of MC to 2.5 ppm, NTM cultivability was no more regain from 42 water samples and only one biofilm resulted positive (1/42). Monochloramine resulted very effective although needed to be finely adjusted to get satisfactory results in the control of Legionella as well as other waterborne pathogens.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
