Page 7 - Water_Controls_for_Healthcare
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HOSPITAL
                                                                                     Infection control /                   SOLUTIONS


            PSEUDOMONAS AERUGINOSA                    MONITORING FOR
                                                      PSEUDOMONAS AERUGINOSA
            More than a third of all cases of Pseudomonas   The Department of Health and Social Care (DHSC)
            aeruginosa originate while the patient is in hospital   conducted a study into contamination by Pseudomonas
            care (36.2%).                             aeruginosa in mixers/taps and the water supply system.
            Pseudomonas aeruginosa, requires 2 elements    This study resulted in the publication of technical   Petri dish with Pseudomonas
            in order to develop:                      guidance written specifically for augmented care   aeruginosa cells
            - water at a temperature between 4°C and     units. This latter was incorporated in the revised
             46°C (optimal development between   More       version of the HTM 04-01 Part B in 2016
             30°C and 37°C).                                  which outlines what action to take when
            - oxygen present in the air.     than a ⅓          healthcare facilities become contaminated
                                                                with Pseudomonas aeruginosa.
            Pseudomonas aeruginosa          of Pseudomonas       In order to assess the level of water
            is transmitted by hand by   aeruginosa cases originate   contamination by Pseudomonas
            healthcare staff and via infected   while the patient is in   aeruginosa, the DHSC recommends
            medical equipment. Invasive      hospital care       sampling the first water to be delivered
            surgery presents a high risk of                     from the outlet. Furthermore, to
            transmission of infectious agents.   Source: Public Health England 2019    maximise the recovery of free-floating
                                             Pseudomonas aeruginosa
                                               bacteraemia annual
                                                 figures      bacteria it recommends taking samples:
            There are several levels of                     - at least 2 hours (preferably longer) after
            Pseudomonas aeruginosa contamination.       the last draw-off at outlets used on a daily basis.
                                                      - on outlets that are used infrequently.
            Pseudomonas aeruginosa development
            in the spout                                Monitoring levels
            Pseudomonas aeruginosa primarily contaminates   for Pseudomonas aeruginosa:
            mixer and tap spouts, since it needs a mixture of air
            and water to develop.                          Satisfactory level  < 1 CFU/100mL
            Biofilm, niches and cavities in the spout walls protect   Alert level  1 - 10 CFU/100mL
            the bacteria from treatments, and provide the ideal   Curative action  > 10 CFU/100mL
            environment for the bacteria to proliferate.    CFU/mL: Colony Forming Units/millilitre
            At the outlet, Pseudomonas aeruginosa finds all the
            necessary conditions to develop and proliferate,   For Legionella spp., the alert level is 100 CFU/L
            establishing permanent colonies in mixers and taps.  and the level for curative action is 1,000 CFU/L.
            Even cleaning spouts and flow straighteners regularly   In its report, the DHSC indicates that for
            is ineffective.                           Pseudomonas aeruginosa, the alert level is
                                                      1 CFU/100mL.
            Pseudomonas aeruginosa development        At levels between 1 and 10 CFU/100mL, the DHSC
            in flexible hoses and pipework            recommends a re-test and a risk assessment
            Once established in the biofilm in mixers and taps,   to determine the appropriate measures.
            Pseudomonas aeruginosa continues to develop    For levels over 10 CFU/100mL an engineering survey
            and will gradually colonise the flexibles and pipework   may be necessary to identify problem areas
            unless an effective solution is put in place.  and the remedial action required.
            By this stage it is impossible to eradicate   The results of successive samples will indicate
            Pseudomonas aeruginosa, which then becomes   the source of contamination in healthcare facilities.
            a threat to the entire water system.      A sample with > 10 CFU/100mL for the pre-flush
                                                      sample (1  draw-off) and levels of < 10 CFU/100mL
                                                              st
                                                      for the post-flush sample (2  draw-off) suggests
                                                                           nd
                                                      Pseudomonas aeruginosa contamination at or
                                                      near the outlet. However, if the pre- and post-flush
                                                      samples show > 10 CFU/100mL, the contamination
                                                      source is upstream in the system.
                                                      If the water sample results are satisfactory
                                                      i.e. 0 CFU/100mL the DHSC advises repeat tests
                                                      every six months.
                                                      In its report the DHSC clearly indicates that
                                                      disinfecting the water supply (hot and cold) is
                                                      insufficient for removing an established biofilm.
                                                      It recommends that, where installed, removable
                                                      taps should be periodically removed for internal
                                                      cleaning to remove any biofilm and bacteria residing
                                                      within. Healthcare facilities should establish regular
                                                      cleaning protocols.
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