Environmental Decontamination


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Environmental Decontamination:
Paradigms Redefined

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Environmental Decontamination

  1. 1. The presentation is solely meant forAcademic purpose AIFIC 13
  2. 2. Environmental Decontamination: Paradigms Redefined
  3. 3. Disclosures- nil
  4. 4. History800 B.C – Homer described the burning of Sulphurin the house4th century A.D. – Susruta used sulphur to cleanrooms for surgeryMercury, copper, alkalis acids all were used for‘Purifying’429 B.C Hippocrates recommended fumigation byburning odoriferous herbs to control an epidemic
  5. 5. 1850’s- Crimean warAdvocated pure air, pure water,efficient drainage, cleanliness andlight as the cornerstones of goodhealth and prevention of mortality
  6. 6. ProjectInfection control Hospital Engineering Housekeepi ng AIFIC 13
  7. 7. The hospital environment It is important to maintain a healthy environment What best infection control practices are available? How to use it cost effectively to protect patients and health care workers from infectious hazards?
  8. 8. Chain of infection
  10. 10. VRE & environment Found in 7-37% environmental samples More common if patients have diarrhoea Nurses gowns contaminated 8% of cultures positive even after terminal cleaningBoyce 1994, Montecalvo 1995, Boyce 1995
  11. 11. MRSA & environment Burns unit – attack rate 75%- 33 of 145 environmental swabs positive Hydrotherapy facilities contaminated Surgical units without MRSA problem-1 of 36 samples positiveCrossley 1979
  12. 12. MRSA & environment 25 rooms of MRSA positive patients 53.6% surface samples positive 28% of air samples Molecular typing PFGE 70% of patient and environmental swabs indistinguishableSexton et al JHI 2006
  13. 13. A. baumanii & environment 50 ICU rooms occupied with patients having MDR AB 9.8% (47 of 479) of the environmental surfaces were contaminated with MDR-AB. Supply cart handles were the most frequently contaminated surface (20%), room floors (16%), infusion pumps (14%), ventilator touch pads (11.4%) and bed rails (10.2%). Am J Infect Control 2011;39:711-715
  14. 14. MDRO’s in environment Vancomycin-resistant enterococci (VRE), Clostridium difficile*, and multidrug- resistant gram-negative bacteria (MDR- GNB) are increasing Hence increasing attention being paid to the role of high-touch environmental surfaces in transmission *Am J Epidemiol. 1988 Jun;127(6):1289- Am J Infect Control 2010;38:S25-33
  15. 15. Environmental surfaces Do environmental surfaces play a role in initiating infection? OR Merely reflect the presence of a source patient contaminating his surroundings?
  16. 16. Environmental surfacesPrimary role Secondary role • Source patient (occupant of room or • Source patient 1 1 reusable eqpt) • Environmental • Environmental 2 surface surface 2 • Hands of HCW 3 • Subsequent patient 3 4 • Subsequent patient AIFIC 13
  17. 17. Klebsiella in environment Outbreak of Klebsiella pneumoniae in NICU- 3 cases Investigations included- handwashing compliance monitoring, disinfectant usage, focussed cleaning Swabs from incubators, ventilator tops, mobile phone of doctors to look for specific pathogen
  18. 18. Klebsiella in environment Klebsiella pneumoniae with similar antibiogram was isolated from the top of ventilator. Increased emphasis of focused cleaning in and around the patients Outbreak curtailed
  19. 19. Cleaning and disinfection of surfaces Dry surface – Gram positive cocci, fungi Wet surface – Gram negative bacilli Cleaning with soap and water or detergent or disinfectant
  20. 20. Standard environmental cleaning methods Manual cleaning and then application of disinfectant or detergent/disinfectant New disinfectants with greater potency and shorter contact times
  21. 21. Detergent or disinfectant? Study 1 Tertiary care 8 wards Phenolic disinfection vs detergent 6 months, random selection of wards Users blind to product used No difference in HAI ratesDanfoth JHI 1987
  22. 22. Detergent or disinfectant? Study 2 ICU floors cleaned 3X daily 6 months detergent 6 months disinfectant Bedside tables, bed frames etc cleaned with disinfectant No difference in HAI ratesDashner 1980
  23. 23. Detergent or disinfectant? 1960’s Vesley and Micaelsen – detergents can achieve microbial reduction equivalent to disinfectants* Maki et al- no change in infection rates in new and old hospital and new environment was contaminated to old rates in 6-12 months*Appl Environ Microbiol 1987:53;1042-1045
  24. 24. Cleaning agents - detergentsCleaning Agent ManufacturerSapona Inter national Hygiene ProductsTeepol - 300 Reckett and ColemanSpiral Hindustan LeverAjax Colgate PalmoliveFesca MetropoleWizard Quartz Home CareBrisk Modi IndustriesSpick and Span Etoshapan JAHA Vol. 13, No. 1 (2001-01 - 2001-06
  25. 25. Detergent-disinfectantDetergent DisinfectantsPolysan - (Akyl phenoxy poly active Polyphan Pvt. Ltdingredient ethoxy - ethanol, iodine)Germinol Etosha panLamp phenyl Bengal chemicalsTrishul phenyl Ampey LeanPhoenix Metro poleDettol-H - (Ben 2 alkonim chlorid sol. 1. Rickett and ColmanP40 1v/v disodeim edeati)Bacilloid Special _ ( D. hydroxy - 2,5,Dioxyhexene glutaaldehydi, Raman Pvt. Ltdde n 201 konuim chloride, caxosguanidiamehlondi) JAHA Vol. 13, No. 1 (2001-01 - 2001-06
  26. 26. Properties of disinfectantsProperties Phenolic Quaternary Iodophor peroxidesEffectivenessagainst S. aureus Fair to good Good Good goodM tuberculosis Fair to good Good Good goodEffect on organicmatter Good Good Fair goodSkin irritationproperites Harsh Mild Mild mild Strong toOdour mild Mild Mild mildpH of use Alkaline(pH9. Neutral or Acidic(pH3.soulution 10) alkaline(pH7.10) 6)Soil removalproperty Poor to good Good Fair fair Safe atCorrosion to floor correctSurface dilutions Safe Safe safe JAHA Vol. 13, No. 1 (2001-01 - 2001-06
  27. 27. Choice of disinfectant Cost Area to be disinfected- steel OT – lysoformin Vinyl floors- QAC (benzalkonium chloride) Room occupied with patient with Clostridium difficile – Hypochlorite solutions
  28. 28. Choice of disinfectant / detergent Operation theatres , BMT units , ICU – disinfectant after cleaning Wards – disinfectant/ detergent General areas- detergent
  29. 29. Factors affecting Disinfection of surfaces First clean with detergent and surfactant to remove organic matter, salt and visible soils. The physical action of scrubbing and rinsing removes large numbers of microorganisms
  30. 30. Strategies for Cleaning and disinfection of surfaces Potential for direct patient contact Degree and frequency of hand contact Potential contamination of surfaces with body fluids and environmental contamination Choice of disinfectant – QAC, hypochlorites, hydrogen peroxides, lysoformin etc
  31. 31. Housekeeping surfaces Surfaces with minimal hand-contact – ceiling, floor Areas with frequent hand-contact – high touch surfaces (door knobs, bed rails, wall around toilet, light switches, edges of curtains) require more cleaning/ disinfection
  32. 32. Cleaning solutions and tools – a source of pathogens Solutions to be replaced frequently Two bucket system to be used Mop heads to be changed at each shift Mops to be dried before use Detergent / disinfectant solutions can support Gram negative bacteria (pseudomonas) if stored for a long time
  33. 33. Newer Strategies for Terminal Room Decontamination“Nontouch disinfection” (NTD) methods Microcondensation hydrogen peroxide vapor hydrogen peroxide dry mist system gaseous ozone alcohol/quaternary ammonium power sanitizing system ultraviolet light room decontamination
  34. 34. HP Vapour & UVGI Both methods appear highly efficacious in inactivating the microbial bioburden present on surfaces Both remove much of the variance inherent in human cleaning activity via a high degree of automation and feedback loops for verification that contact or irradiation times are adequate
  35. 35. HPV efficacy v/s standard disinfectant  Patients admitted to rooms using HPV were 64% less likely to acquire any MDRO (esp VRE).  The proportion of rooms environmentally contaminated with MDROs was reduced significantly on the HPV units (relative risk, 0.65, P = .03), but not on non-HPV units.Passaretti et al .Clin Infect Dis. 2013:56:27-35.
  36. 36. UV light disinfection An automated mobile UV light unit that emits UV-C light was placed in 25 patient rooms after patient discharge and operated The mobile UV-C light unit significantly reduced aerobic colony counts and C. difficile spores on contaminated surfaces in patient rooms Infect Control Hosp Epidemiol2011 Aug;32(8):737-42.
  37. 37. Contact precautions for MDRO, C. difficile  Single room  Use of gloves and gown when in contact with patient / patient environment  Donning PPE at room entry and discarding before exiting room  Duration of precautions is not knownhttp://www.cdc.gov/ncidod/dhqp/pdf/isolation2007.pdf
  38. 38. The need for terminal cleaning and disinfection Previous room occupancy by patients with VRE or MRSA increases risk for acquiring these multidrug-resistant organisms in patients subsequently admitted to the same rooms. Arch Intern Med. 2006;166:1945-1951 Arch Intern Med. 2003;163:1905-1912 Clin Infect Dis. 2008;46:678-685.
  39. 39. Hayden et al. Clinical Infectious Diseases 2006; 42:1552–60
  40. 40. Other factors Carpets to be avoided (especially in ICU, OR, BMT units) If flowers are present, the water should be changed frequently and these should be handled by staff not having patient contact Flowers (fresh and dried ) can harbour Aspergillus spores
  41. 41. Monitoring Cleaning and Disinfecting Practices Have housekeeping managers conduct visual inspection (not reliable) Mark high touch surfaces with a fluorescent solution and check later to determine whether the mark has been removed by housekeepers during room cleaning Count aerobic colonies of specimens obtained from high touch surfaces Use adenosine triphosphate (ATP) bioluminescence assay to assess the cleanliness of surfaces
  42. 42. Monitoring cleaning practices  Terminal cleaning is often suboptimal.  Only about 50% of the surfaces in patient rooms that should be cleaned are wiped by housekeepers.  This phenomenon has been documented in different types of hospitals and intensive care units as well as on general medical or surgical wards. Infect Control Hosp Epidemiol. 2008;29:593-599Clin Infect Dis. 2006;42:385-388, Infect Control Hosp Epidemiol. 2008;29:1-7
  43. 43. Feedback & Education  Providing housekeepers with feedback about the results of such monitoring and educating them about the importance of their activities has led to significant improvements in the proportion of surfaces that are cleaned by housekeepersInfect Control Hosp Epidemiol. 2009;30:678
  44. 44. AirSurgical site exposes sterile tissue to microorganisms from : respiratory droplets and nuclei, skin scales carried on air currents, direct contact with the surgical teams skin, and contaminated fomites. The route with the most significant potential for iatrogenic bacterial transfer is direct physical contact. Dermatol Surg. 2011 Dec;37(12):1709-20
  45. 45. Microbial contamination of air Talking – 3000 droplet nuclei Sneezing – 40,000 droplet nuclei Sweeping Dry plants Staphylococci, Streptococci, Fungal spores
  46. 46. Strategies to reduce air contamination Filtration Air changes Pressure differentials Ultraviolet installations Laminar air flow
  47. 47. Special ventilation areas Isolation room BMT unit Operating roomAir pressure Negative Positive PositiveRoom air ≥12 ≥ 12 ≥ 20changesSealed Yes Yes yesRoom leakage (0.1 cfm/ft2 ) (0.1 cfm/ft2 ) (0.1 cfm/ft2 )Directed airflow Clean- to- dirty Clean- to- dirty Displacement (HCW clean) (patient clean) flow in surgical site criticalFiltration supply 90% 99.97% HEPA 90% @0.3um
  48. 48. Verification of ventilation parameters Pressurisation Air changes Filtration – non microbiologic method – particle count
  49. 49. Air – particle count Non viable airborne particles detected by particle counter, optical or laser. Particle size >0.5 um used for assessing clean room
  50. 50. Clean room classification - ISO Classification based on HEPA filtered (99.7% efficient at 0.3 um diameter particles) operating room or BMT room with no people should be capable of class 1000 clean room status (there are <1000 particles per cubic foot >0.5 um in diameter)
  51. 51. Clean room classification - ISO
  52. 52. Hydroxyl radical air disinfection system A comparison of air counts and environmental contamination rates was made with the Inov8 units on and off. The Inov8 unit produced an overall reduction in both air sample and settle plate counts in each setting (P < 0.001) ? Effect on specific pathogens ? Safety issues for patients and HCW J Hosp Infect. 2011:78;194-99
  53. 53. Ozone Ozone fumigation successfully controlled and eradicated multidrug-resistant Acinetobacter baumanii from an intensive care unit Environmental samples positivity decreased from 31% to 7 % following ozone fumigation R Stümpfle et al Critical Care 2010, 14(Suppl 1):P67
  54. 54. Water and HAI Respiratory therapy equipment Fiberoptic endoscopes Faucet shower heads with Pseudomonas Shower heads and Legionellosis Faucet aerators & Stenotrophomonas maltophilia
  55. 55. Water reservoirs Hot water supplies Hydrotherapy pools and tanks Potable water Sinks Water baths Dialysis water Toilets Dental unit water systems
  56. 56. Dialysis fluid Contamination by Gram negative bacteria Monthly testing for bacterial counts and endotoxin levels
  57. 57. AAMI standards for dialysis fluidHemodialysis Method Maximum Max.fluid heterotrophs endotoxin (cfu/ml) level (EU/ml)Product water Plate count 200 2 500ul on TSADialysate LAL gel clot 200 2 assay ANSI/AAMI RD52:2004 Dialysate for hemodialysis
  58. 58. Environmental decontaminationEarlier thoughts Current concepts• Fumigation with • Focused cleaning of formalin- the final high contact areas solution to a clean • Isolation of patients environment with MDR • Terminal cleaning • Vapour methods AIFIC 13
  59. 59. Microbiologic sampling of environment  Before 1970’s in US, regular scheduled culturing of air and environmental surfaces was done  By 1970, CDC advised discontinuation of routine environmental surveillance as not association of HAI with levels of environmental contamination was noted
  60. 60. Microbiologic sampling of environment – current conceptsUsed currently for: Research (potential reservoirs on surface, survival of pathogens, sources of contamination) As part of epidemiologic investigation Specific QA purposes
  61. 61. Variables affecting sampling Survival of agent (Clostridium spores persist for years, Staphylococcus for months) Interference from particulates- dust, heavy metals Adherence of microorganism Methods of detection
  62. 62. Microbiologic sampling of Environmental surfacesSampling devices: Wipe Swab Agar Contact plate Microvacuum sampling HEPA vacuum collection sock
  63. 63. Microbiologic sampling of Environmental surfaces Use of neutralisers for residual disinfectants Media
  64. 64. Microbiologic sampling of Environmental surfacesResults: Have we found what we were looking for – the target organism? No standard guidelines for validation of surveillance cultures
  65. 65. Environmental surfaces ATP technology for real time analysis of surfaces suspected of being contaminated Bioluminescent material attached to protein or ATP from living cells. Done as a quality audit
  66. 66. Environmental sampling - indications2. For research purposes – for e.g to compare HAI rates in old and new facility before and after occupationCan provide new information regarding spread of HAI
  67. 67. Environmental sampling - indications3. To monitor a potentially hazardous environmental condition, confirm the presence of hazardous chemical or biological agent, to validate the successful abatement of the hazarde.g. to monitor bioaerosols released from health care equipment
  68. 68. Environmental sampling - indications4. For quality assurance purposes to evaluate the effects of a change in infection control practicesOr to ensure that equipment or systems perform according to specifications and expected outcomes
  69. 69. Air sampling Air sampling for qualitative measurement of microbial contamination during prolonged construction to look for breach in environmental control measures Sampling before commissioning special care areas (OR’s, BMT units)
  70. 70. Air Sampling Methods Impingement in liquids Impaction on solid surfaces (slit samplers) Sedimentation (settle plates) Filtration Centrifugation Electrostatic precipitation
  71. 71. Active Air sampling Active air samplers are used, which collect a known volume of air, blown on to a nutrient medium by different techniques. Petri samplers (sieve impaction) Slit samplers
  72. 72. Active Air sampling Lack of uniform air quality standards The microbial air contamination can be measured by counting the number of cfu per cubic metre (cfu/m3) of air.C. Pasquarella*, O. Pitzurra† and A. Savino . The index of microbial aircontamination. Journal of Hospital Infection (2000) 46: 241–256
  73. 73. Passive air sampling -Settle plates The schedule 1/1/1 was devised as a standard The Petri dish must be left open to the air for 1 h, 1m above the floor, 1m from the wall. After 48 h incubation at 36°C the cfu are counted. The number of cfu is the Index of microbial air contaminatopn (IMA).Fisher G, Fodré S, Nehéz M. Z Ges Hyg 1971; 17: 576–579
  74. 74. Standards for colony counts British bacteriological standard for ultraclean operating room air of 10 cfu/m3 Surface contamination rate of 350 cfu/m2/h measured by means of settle plates Friberg B, Friberg S, Burman LG. J Hosp Infect 1999; 42: 287–293.
  75. 75. Maximum acceptable risks of IMA IMA value Cfu/m3/h Performance locations 0-5 0-9 Very good OR- ultra clean, BMT 6-25 10-39 Good Conventional OR, dialysis unit, ICU 26-50 40-84 Fair Wards, day care 51-75 85-124 Poor >76 >125 Very poorC. Pasquarella*, O. Pitzurra† and A. Savino . The index of microbial aircontamination. Journal of Hospital Infection (2000) 46: 241–256
  76. 76. Water sampling Routine water testing is not indicated Done to detect water borne pathogens To determine quality of finished water in the distribution systems To be done in outbreak situations to initiate appropriate infection control measures Dialysis water to be tested monthly
  77. 77. Water sampling Plate count Membrane filtration Potable water – coliform count
  78. 78. Summary Environment can serve as reservoirs for pathogens Hand hygiene is paramount Cleaning and disinfecting environmental surfaces is mandatory Surveillance cultures neither cost-effective nor warranted.
  79. 79. Thank you AIFIC 13