AWWA ACE68639

This powerpoint presentation begins by providing a brief overview of the issue of rapidly growing mycobacteria (RGM), and presents an investigation of an outbreak of M abscessus in a long term care facility. Specifics of the outbreak investigation included: M. abscessus infections in ventilator patients; epidemiology suggested water supply as the source of infection; water testing recovered other RGM, not M. abscessus (M chelonae, M peregrinum, M mucogenicum, unidentified species recovered from multiple faucets over several samplings). Treatment measures included: hyperchlorination, 40 ppm hypochlorite; point-of-use filters, Pall Corporation; filters installed on four sink faucets; and, water examined for HPC (heterotrophic plate count) bacteria and RGM (rapidly growing mycobacteria). The actual laboratory study of chlorine disinfection of M abscessus Biofilm Free Chlorine, pH 7 is presented, with results of M abscessus biofilm grown in drinking water indicating: cord formation increases chlorine susceptibility; and, mycobacteria biofilm tolerates "normal" chlorine residual. Presentation conclusions indicate that: chlorine does not control RGM in healthcare water systems; point-of-use treatment may be best preventive measure; and, improvements needed for RGM detection and isolation methods. Includes tables, figures.