WEBI'MARS Volet 3 L’eau à l’hôpital

Main ideas & lessons (WebMARS Volet 3 — Water in hospitals)

Webinar purpose and structure

• This is the 3rd and final webinar of WebMARS focused on water management in healthcare facilities.
• Topics are split across three speakers, each covering a different angle of water hygiene and risk control.
• The session includes:
  • live questions (oral via mic/hand-raise, and written via a question slot),
  • a replay for 2 months via SF2H newsletter (members only), then public on SF2H YouTube.

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Speaker 1: Mr. Patrick Paris (Sanitary hot water network design & maintenance + Legionella / “cold water” risk handling)

A) Legionella risk: where it starts and why temperature control matters

• Legionella risk is primarily linked to domestic hot water (DHW) systems.
• Key principle:
  • Maintain DHW temperature in recirculation loops above 50°C.
  • This requirement is described in a November 2005 decree (as stated in the subtitles).
• Preferred disinfection approach:
  • Continuous thermal disinfection is favored over chemical approaches because:
    • thermal methods avoid chemical-agent degradation of materials,
    • chemical disinfection (examples mentioned: sodium chloride, chlorine dioxide) can damage network materials.

B) Where Legionella contamination can originate (design/maintenance failures)

• Contamination can occur upstream, especially:
  • water softeners, particularly pre-filters (contamination of filter media),
  • softener resins showing contamination.
• Temperature constraints for components:
  • rooms housing equipment should remain below ~15°C (as claimed by the speaker) and avoid nearby heat sources.
  • inadequate ventilation/insulation leads to equipment temperature being too high, worsening risk.

C) DHW tank design and circulation problems

• Common failures even when systems exist:
  • temperature stratification failures inside tanks (hot at the top, bottom becomes lukewarm),
  • “bottom return/recirculation not circulating” due to design choices → promotes bacterial growth.
• Tank design matters:
  • the speaker stresses considering stratification (diagrams, return positioning) during design.

D) Heat production systems & required monitoring

• System types mentioned:
  • heat exchangers and tank-based production.
• Monitoring concepts (as stated):
  • primary lines (energy delivery temperatures),
  • secondary lines (contaminated/carrying water temperatures).
• Secondary line monitoring referenced to Feb 1, 2010 decree:
  • monitoring at supply/return points and within tanks (if present).

E) Design flaws to eliminate (high risk due to mixing)

The speaker provides multiple “eliminate/replace” recommendations:

• Remove mixing valves on hot water outlets:
  • mixing valves are described as unacceptable due to Legionella risk.
• Eliminate mixer taps at terminal points:
  • “mixing should be eliminated”;
  • even shower supply systems should avoid mixing arrangements where risk can occur.
• Avoid inaccessible pipe sections:
  • networks embedded under slabs (hard to maintain/inspect) are flagged as unacceptable, including worker-safety and difficulty of corrective action.

F) Scaling & corrosion: mitigation through water preparation and material choice

• Reduce scaling by softening DHW:
  • target softening around 8–10 French degrees (further reducing corrosion risk).
• Corrosion issues relate to:
  • unsuitable pipe materials and aging/obsolescence.
• Solution direction:
  • replace networks with suitable modern materials (examples mentioned: copper, PVC, multilayer pipes).

G) Recirculation loop balancing: preventing return temps dropping under thresholds

• Balancing governed by Nov 30, 2005 decree (as cited).
• Observed problems:
  • lack of installed balancing devices,
  • balancing systems failing → return temperatures below 52°C (risk on return lines).
• Practical method:
  • use balancing valves that allow measurement of:
    • flow and temperature at measuring ports (without intrusive shutdown).
  • ensure accessibility (height/duct planning) to allow maintenance and monitoring.
• Annual checks:
  • example “balancing plan” and statement that loop temperatures should be verified yearly.

H) Additional Legionella risk points in practice

• Degassers (air vents) at risers:
  • must be maintained/used correctly to vent released air; otherwise recirculation can fail.
• Insulation failures:
  • lead to energy loss and temperature dropping below thresholds → Legionella risk.

I) Accessibility + monitoring via building management systems (BMS)

• Strong emphasis:
  • ensure access panels are removable and adequately sized.
  • poor accessibility increases risk because networks can’t be inspected/maintained properly.
• Use of BMS:
  • example given (Cochin Hospital): continuous tracking of domestic hot water return temperatures.

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Speaker 1 (continued): Cold water and “biophilia” (biofilm prevention rather than total eradication)

A) Key concept: cold water contamination is about biofilms

• “We can’t eradicate biophiles” in cold water.
• Strategy:
  • limit biofilm development,
  • control conditions that allow growth and thickening.

B) Target organisms/thresholds (as described)

• Targets in cold water:
  • flora at 22°C: target < 100 CFU/mL (as stated),
  • flora at 36°C: target < 10 CFU/mL (described as most difficult),
  • Pseudomonas:
    • assessed under 22–36°C conditions,
    • coliforms should be very low; significant coliform presence suggests localized contamination.
• Thresholds are framed as targets rather than only “pass/fail.”

C) Primary sources of contamination

• Sources:
  • hands during use (especially with aerators),
  • contamination during pipe installation,
  • soil-related contamination.
• Risk locations/equipment:
  • sinks, treatment stations, showers.
• Shower heads:
  • require cleanliness (examples of unacceptable vs acceptable fixtures).

D) Terminal areas: maintenance is decisive

• Operating rooms (as mentioned):
  • terminal filters can reduce germ risk when correctly installed.
• Focus for “terminal parts” maintenance:
  • aerators, nozzles, end devices; cleaning/disinfection.

E) Maintenance interventions and procedures (structured “how-to”)

• Cleaning/disinfection of terminal water points (without full dismantling):
  • Clean regularly (minimum weekly for certain terminal points, as stated).
  • Use products proven effective against target bacteria (verify with supplier).
  • Avoid assuming chemical disinfection always works; effectiveness varies and recurring issues can occur.
• Constraints on disinfection:
  • terminal parts are often not designed to tolerate chemical/thermal decontamination.
  • if chemical/thermal approaches are insufficient:
    • add injection/bridging points under sinks (hot/cold bridging), or
    • replace faucets (financially suboptimal but sometimes adopted).
• Traceability and evidence:
  • establish documented procedures:
    • how actions are done,
    • who does them,
  • store documents in the facility health record for evidence and response.
• Thermal disinfection caution:
  • avoid overly long contact times because materials in contact can be damaged.

F) Water-point usage prevention (reduce stagnation)

• Recommendation:
  • draw water from all points at least every two days.
• If points aren’t used at full flow:
  • flush/let run for ~4 minutes (mixed or cold as described).
• Regular flushing reduces biofilm and improves test results.

G) Design for new/renovated networks

• Principles:
  • keep the network simple (planning phases such as APS/APD/PRO referenced before execution),
  • avoid complex networks that are hard to balance and maintain,
  • avoid unnecessary thermostatic mixers:
    • choose simpler taps if thermostatic control isn’t needed,
  • ensure accessibility from the outset,
  • plan for unused outlets (simulate use via flushing).

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Speaker 2: Dr. Didier Lecointe (Legionella risk management “in practice” — monitoring, diagnosis, crisis response, investigations)

A) Legionella biology and why water systems create risk

• Legionella:
  • described as Gram-negative aquatic-adapted bacterium in rivers/lakes/mud.
• Temperature effects (as described):
  • multiplication often between ~25–45°C,
  • reduced survival at >50°C,
  • quick activation around ~60°C (as stated).
• VBNC-like state (dormant/undetectable):
  • disinfectants may not eliminate it effectively,
  • can create false negative cultures.

B) Reservoir and transmission mechanisms

• Legionella linked to biofilms and free-living aquatic organisms:
  • biofilms act as reservoirs,
  • spread occurs when conditions allow.
• Water networks create “stagnation zones”:
  • complex production/distribution creates areas favoring biofilm growth.
• Healthcare aerosolization risks:
  • showers and rehabilitation baths are cited as key aerosol generators without single-use mitigation.

C) Clinical considerations: Legionnaires’ disease and Pontiac fever

• Pontiac fever:
  • described as a benign flu-like syndrome.
• Legionnaires’ disease:
  • pneumonia with potentially fatal outcomes.
• Diagnostic challenges:
  • urinary antigen testing is specific but not fully exclusionary,
  • urinary antigen can remain positive for months → complicates attribution window,
  • respiratory samples are needed to obtain clinical strain for comparison with environmental strains.

D) Regulatory framework (texts to know)

Dr. Lecointe highlights key French texts (as cited):

• Circular April 22, 2002
• Decree Feb 1, 2010
• Circular Dec 21, 2010
• These are presented as the core monitoring/compliance rules; later texts refine or apply them for public-facing facilities.

E) Core prevention methodology (monitoring + sampling + network design)

1) Temperature monitoring (DHW loop principles)

• Monitor DHW temperature (preferably continuous).
• Targets described:

  • 55°C at loop start,

  • ≤5°C difference with return,

  • 50°C at points of use.

2) Periodic Legionella analysis

• Enumeration of Legionella with counts aimed to remain low CFU/L (as stated for general and high-risk settings).
• Sampling must follow standards and accreditation requirements.

3) Network design recommendations

• Keep loop sizes as small as possible:
  • smaller loops are easier to balance.
• Ensure correct balancing and distribution.
• Prefer plate heat exchangers (as stated).

4) Terminal point upkeep

• Before crisis:
  • disinfect faucets/showerheads by flushing hot water,
  • ensure >52°C for effective flushing (as stated),
  • systematic descaling.

5) Sampling plan principles

• Sampling should be representative and risk-informed:
  • include disadvantaged/most at-risk points,
  • include points in high-risk departments,
  • include recently installed/renovated areas.
• Include return-flow considerations as described.

F) Crisis management (“when threshold exceeded”)

Corrective steps outlined like a procedure:

• First step: investigate and act on the network
  • global thermal disinfection:

    • 70°C after flushing entire network,

    • flush at sufficient velocity (as stated).
  • if feasible:
    • use biocides locally where appropriate.
• Terminal interventions
  • terminal filtration if disinfection at points of use isn’t feasible.
  • change/renew:
    • “filters” at fixtures (freeze shields mentioned),
    • flexible hoses.
  • reinforce:
    • hot water flushing,
    • descaling.
• Verification
  • run a control sampling campaign about 8 weeks later (as stated),
  • ensure results return to normal; if not, repeat corrective measures.

G) Investigation case examples (why strain matching matters)

• Cases where home water was source:
  • clinical strain matched environmental strain in home hot water tank.
• Cases where assumptions were wrong:
  • municipality source suspected, but ARS network findings didn’t match the identified strain.
• Emphasis:
  • comparing clinical strain to environmental strain using proper respiratory sampling is crucial for attribution.

H) Key “limitations of testing” messages

• False negatives can occur due to VBNC-like states.
• Urinary antigen tests must be interpreted carefully.
• Respiratory samples are essential to obtain clinical strains.

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Speaker 3: Ms. Céline Cioti (Water controls in healthcare: categorization Q1/Q2/Q3/Q4; practical sampling and routine monitoring)

A) Water classification and where it fits

Using a 2005 healthcare water guide framework (as stated):

• Q1: water undergoing no treatment
  • Q1 (incoming at entry) and Q1b (point of use).
• Q2: water that undergoes treatment
  • includes treated bacteriological waters (SS), hot water, swimming pool water, hemodialysis-related waters, etc.
• Other categories are referenced, but the focus is mainly on Q1/Q2.

B) Q1 controls: potability and frequency

• Q1 water:
  • potability criteria linked to the Public Health Code article (as stated).
• Monitoring approaches:
  • incoming water monitored by municipality/distribution company,
  • at point of use:
    • recommended assessment frequency described as roughly 1 assessment/year per 100 beds, minimum 4/year (as stated).

C) Q1 microbiological quality: targets and action levels

• Targets referenced:
  • flora at 22°C and 36°C thresholds (with CFU/L or CFU/mL framing).
• Action logic:
  • if values deviate significantly (example concept: ~10x ratio), corrective action is triggered.
• Additional tests:
  • coliforms and Pseudomonas aeruginosa.

D) Sampling frequency and practical monitoring plan

• No single strict regulation frequency was claimed; guide suggests quarterly.
• Example practice:
  • test all care stations at least once per year,
  • add representative shower sampling in high-risk departments,
  • distribute sampling across the year to avoid overloading labs.

E) Q2 treated waters: what is tested depending on treatment type

• Treated bacteriological controlled waters (SS):
  • often tested for reversible flora at 22°C and Pseudomonas (as described).
  • when using single-use filters, microbiological testing may not be necessary except in specific regulatory cases (example mentioned: endoscope washer/disinfector final rinse water → quarterly testing).
• Hot water (Legionella risk):
  • reserved for hygiene/equipment maintenance; not for preparing drinks/food.

F) Swimming pool & aerosol risk management

• No Legionella testing in pool water itself, but in shower water (aerosolized risk).
• Pool disinfection logic:
  • monthly frequency, morning before sessions begin when no one is present.
• Elderly whirlpool/rehabilitation sessions:
  • monthly morning testing and disinfection due to aerosols.

G) Hemodialysis and specialized water

• Multiple circulars referenced for dialysis water control (as named):
  • Jan 30, 2007 and June 20, 2000 (as stated).
• Sampling targets depend on technique:
  • conventional hemodialysis vs diafiltration (described as needing different sampling points and CFU expectations).
• Add endotoxin testing in purified/ultrapure systems.

H) Purified/highly purified pharmaceutical waters

• Intended for medicine preparation per European Pharmacopoeia.
• Often produced by reverse osmosis.
• Responsibility for sampling frequency shifts to the producer (as described).

I) Drinking-water coolers (refrigerated fountains)

Pros

• available 24/7
• less waste than bottled water

Cons

• maintenance complexity:
  • descaling and daily upkeep responsibilities must be clearly defined (to avoid “not my job” gaps).
• Include these systems in drinking water campaigns and possibly Legionella campaigns where aspiration risk exists.

Advice

• prioritize fountains with:
  • reservoir-free,
  • carbon-filter-free,
  • automatic purging,
  • non-return valve.

J) Study: tap water vs bottled water microbiological quality

• Study design (as described):
  • PCA incubation at 30°C for 72 hours,
  • identification using methods mentioned.
• Results summary:
  • bottled spring/crystal-clear sources had higher mesophilic flora frequency than tap water,
  • pathogens were detected in some bottled samples, while tap water showed fewer problems.
• Conclusion:
  • tap water network quality presented as superior to some bottled sources in their region,
  • also notes logistical costs if bottled water is stopped (chilling equipment, containers, etc.),
  • encourages rationalized controls and risk-based testing.

K) Q&A themes (filters, sampling points, flushing, disinfection frequency)

• Sink filters (oncology and surgical troughs):
  • recommend risk analysis and sampling; not automatically for all points.
  • for surgical handwashing: may not require bacteriologically controlled water/filters, but remove filters if they are not maintained.
• Sample domestic water heaters:
  • only in specific contexts (e.g., on-call rooms, accommodations).
• Flushing during work:
  • emphasizes controlling water quality and maintaining traceability.
• Automatic flushing taps vs manual flushing:
  • preference for structured frequent purging (e.g., every two days) over leaving systems dripping.
• Mixed vs cold purging:
  • “purging is purging” (volume renewal) rather than thermal disinfection.
  • time depends on branch length and layout; “4 minutes” tied to an 8-meter branch renewal logic.
• Disinfection at point of use:
  • start with descaling and remove/replace broken/aerator-related components.
  • vinegar (acetic acid) suggested for descaling where appropriate.
  • thermal disinfection used selectively (example: boiling water for ~1 hour for contaminated points).
• Chlorine dioxide and oxidants:
  • cautious use; preference for temperature-based control.
  • continuous chlorine dioxide debated as potentially damaging network materials.
• Dead legs:
  • keep them as short as possible; avoid stagnant segments.

L) Decree update controversy (Dec 30, 2022, sampling standard references)

• Discussion about inconsistencies between older standards (e.g., FDT/FDT 8522) and the decree.