Infection Control- Preventing Nosocomial Infections Yehuda Carmeli, MD, MPH Division of...
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Transcript of Infection Control- Preventing Nosocomial Infections Yehuda Carmeli, MD, MPH Division of...
Infection Control- Preventing Nosocomial Infections
Yehuda Carmeli, MD, MPH
Division of Epidemiology,
Tel Aviv Sourasky Medical Center
Nosocomial Infections
• Infections acquired in hospitals – (or healthcare setting)
• How bad can it get ?– Hotel -Dieu, Paris (the largest and richest of
all hospitals) mid-18th century• 1,000 beds, 3,000 patients• Water directly from the Seine• Wounds clean with shared towels
How bad it was
• All wounds became infected
• Mortality after amputation >60%
• Puerperal fever was common, and during an epidemic in 1746, 95% of postpartum women died
• Hospitals described in 1850: “The gates that lead to death”
Ignaz Semmelweis, 1815-1865
• 1840’s: General Hospital of Vienna
• Divided into two clinics, alternating admissions every 24 hours:– First Clinic: Doctors and
medical students– Second Clinic: Midwives
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2First Clinic Second
Clinic
Semmelweis
“hand disinfection”
The Intervention:Hand scrub with chlorinated lime
solution
Hand hygiene basin at the Lying-In Women’s Hospital in Vienna, 1847.
Mortality Semmelweis
Hand Hygiene: Not a New Concept
Maternal Mortality due to Postpartum Infection General Hospital, Vienna, Austria, 1841-1850
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MDs Midwives
Semmelweis’ Hand Hygiene Intervention
~ Hand antisepsis reduces the frequency of patient infections ~
Adapted from: Hosp Epidemiol Infect Control, 2nd Edition, 1999.
Hand Hygiene Adherence in Hospitals
1. Gould D, J Hosp Infect 1994;28:15-30. 2. Larson E, J Hosp Infect 1995;30:88-106. 3. Slaughter S, Ann Intern Med 1996;3:360-365. 4. Watanakunakorn C, Infect Control Hosp Epidemiol 1998;19:858-860. 5. Pittet D, Lancet 2000:356;1307-1312.
Year of Study Adherence Rate Hospital Area
1994 (1) 29% General and ICU
1995 (2) 41% General
1996 (3) 41% ICU
1998 (4) 30% General
2000 (5) 48% General
Self-Reported Factors for Poor Adherence with Hand Hygiene
Handwashing agents cause irritation and dryness
Sinks are inconveniently located/lack of sinks
Lack of soap and paper towels
Too busy/insufficient time
Understaffing/overcrowding
Patient needs take priority
Low risk of acquiring infection from patients
Adapted from Pittet D, Infect Control Hosp Epidemiol 2000;21:381-386.
Ability of Hand Hygiene Agents to Reduce Bacteria on
Hands
Adapted from: Hosp Epidemiol Infect Control, 2nd Edition, 1999.
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Alcohol-based handrub(70% Isopropanol)
Antimicrobial soap(4% Chlorhexidine)
Plain soap
Time After Disinfection
Baseline
Efficacy of Hand Hygiene Preparations in Killing
Bacteria
Good Better Best
Plain Soap Antimicrobial soap
Alcohol-based handrub
Definitions• Hand hygiene
– Performing handwashing, antiseptic handwash, alcohol-based handrub, surgical hand hygiene/antisepsis
• Handwashing– Washing hands with plain soap and water
• Antiseptic handwash– Washing hands with water and soap or other detergents containing
an antiseptic agent
• Alcohol-based handrub– Rubbing hands with an alcohol-containing preparation
• Surgical hand hygiene/antisepsis– Handwashing or using an alcohol-based handrub before operations
by surgical personnel
Guideline for Hand Hygiene in Health-care Settings. MMWR 2002; vol. 51, no. RR-16.
Infection Rates: Surgical Handscrub vs.
Handrub2 Test of
Class of No. SSI/No. Operations (%) EquivalenceContamination Handscrub Handrub (p-value)
Clean 29/1485 (1.9) 32/1520 (2.1) 16.0 (<0.001)
Clean- Contaminated 24/650 (3.7) 23/732 (3.1) 1.9 (0.09)
All 53/2135 (2.5) 55/2252 (2.4) 19.5 (<0.001)
Parienti et al. JAMA 2002: 288(6);722-27.
Specific Indications for Hand Hygiene
• Before:– Patient contact – Donning gloves when inserting a CVC– Inserting urinary catheters, peripheral vascular
catheters, or other invasive devices that don’t require surgery
• After:– Contact with a patient’s skin, body fluids or excretions,
non-intact skin, wound dressings– Contact with a patient’s close environment– Removing gloves
Guideline for Hand Hygiene in Health-care Settings. MMWR 2002; vol. 51, no. RR-16.
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Alcohol rub Soap and water
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Baseline 2 weeks
Alcohol rub Soap and water
Epidermal water contentSelf-reported skin scoreDry
Healthy Dry
Healthy
Effect of Alcohol-Based Handrubs on Skin Condition
~ Alcohol-based handrub is less damaging to the skin ~
Boyce J, Infect Control Hosp Epidemiol 2000;21(7):438-441.
Pasteur“germ theory of disease”
ListerAsepsis
Aseptic techniques
• Asepsis - Prevention of microbial contamination of living tissues or sterile materials by excluding, removing or killing micro-organisms.– Disinfectant - An agent that is intended to kill or
remove pathogenic micro-organisms, with the exception of bacterial spores.
– Pasteurization - A process that kills nonspore-forming micro-organisms by hot water or steam at 65-100oC.
– Sterilization - The complete destruction of micro-organisms.
Source of organisms
• The patient– preparation of the site
• The environment– cleaning and disinfection
• Surgical tools and materials– sterilization
• the personnel– protective dressing
Sterilization
• Critical items – Items which enter sterile tissue or vascular
system.– High risk if any organism or spores survive.
• Complete elimination of all viable microorganisms including spores.
• Sterility is a probabilistic phenomenon and not all-or-none
October 18, 2000: 250-million-year-old
bacteria revived
Killing Curve
1.00E+00
1.00E+01
1.00E+02
1.00E+03
1.00E+04
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1.00E+07
0 1 2 3 4 5 6 7 8
Time
Via
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org
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Resistant sub-populations
Decimal reduction time:Overall population=1Resistant subpopulation= 2 , 3 , >3
cleaning
Bacterial Growth Curve
WT
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Time (h)
Lo
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Netherlands standard
• Shelf life determined by:– method of sterilization – equipment– packing material– transport– storage conditions
Difficult to trace
• Infections (SSI) are difficult to trace to problem in sterilization
• Thus, we are dependent on perfect process, with overkill threshold.
Florence Nightingale“hospital hygiene”
Patient to patient transmission
• Routes of transmission– Air born– Blood born– Fecal oral route– Contact– Vector
Blood Borne
• HBV, HCV, HIV (and many more)
• Patient to patient: Blood transfusion
• Patient to HCW (and vice versa)– Primarily by needle stick– Surgery– contact of skin or mucus membranes with
blood
Prevention of Blood Transmission
• Patients to HCW: • Universal precautions: Treat all body fluid as
infected.– Use of gloves for contact with blood or patients
secretions (except sweet)– Surgery –double gloving– Protect mucus membrane when likely to be
contaminated– care with sharp objects
*post exposure prophylaxis
Transmission by contact
• The most important route of transmission today
• Transmission is usually on the hands of HCW
• Occasionally inanimate objects (stethoscopes, thermometers)
• Hands can be contaminated from the environment
Prevention of Transmission of Air Born Organisms
• Aerosol :– single room – Negative pressure & filters– High performance mask on entry
• Droplets:– Single room– Mask– Ventilated patients close-suction system
Contact transmission is preventable
• Hand hygiene is the most important measure to prevent transmission
• Compliance is low– Role models are missing– Physical conditions are a barrier– Time constrains
• New advances and increased awareness– Hand disinfection
• New trainees will bring the change ?
Contact precautions
• For patients with multi-resistant organisms
(VISA, VRE, MRSA, C. diff, others )– isolation– gloves and gowns– hand washing
Standard precautions
• Incorporates the concepts of universal precautions and body substances precautions– Universal precautions– Gloves for contact with dirty/contaminated
area– Change gloves between contaminated and
clean body sites– HW after patient contact (even after gloves)
Most Common Nosocomial Infections
• Blood stream infections (BSI)
• Surgical site infections (SSI)
• Nosocomial pneumonia (ventilator associated pneumonia) (VAP)
• Urinary tract infections (UTI)
Most Common Nosocomial Pathogens (NNIS)
Gram positive:• S. aureus• Enterococci• SCN
Gram negative• E. Coli• Klebsiella spp.• P. aeruginosa• Enterobacter spp.
Patient own flora as source of infecting organisms
• GI tract- GNR and entrococci
• Nasopharynx
• Oral flora
• Skin flora
• Changes in flora during hospitalization, and 2nd to underlying conditions
BSI
• Primary bacteremia- almost invariably associated with IV lines, more so with central lines.
• Organisms are mostly skin flora:– S. aureus – SCN – Enterococci
Preventive measures line infections• Reduction of use of lines
– Duration line is in place – Need for line
• Central line versus peripheral line• Proper insertion and care
– Standardized aseptic techniques• Peripheral - hand disnfection + non sterile gloves + no-touch technique• Central and PICC - cap, mask, sterile gown, sterile gloves, and large
sterile drape
– Experienced personnel• Dedicated IV team
Preventive measures line infections
• Choice of insertion site – Peripheral line
• Upper extremities rather than lower extremities• Arm and hand rather than upper arm
– Central line• Subclavian<jugular<femoral
• Skin preparation– Chlorhexidine preparation better than polvidon-iodine or alcohol
• Type of catheter– Low risk – silicone, polyurethane, teflon– High risk PVC, polyethylene– Coated catheters – abx, silver, chlorhexidine
• Dressing– Transparent = gauze (risk of infection)
Other measures for BSI
• Filters – unproven• Antibiotic prophylaxis – not recommended• Topical antibiotics at insertion site –
unproven and contavertial• Antibiotic lock prophylaxis – in neutropenic
patients with permanent catheters –contravertial
• Heparin flush – for short term CVC – prevent thrombi, no proven effect on BSI
More measures to prevent BSI
• Replacement– Peripheral lines - at 72-96h– Midlines ? Two weeks ?– Short term CVC –
• no benefit from routine replacement• No infection benefit from replacement over guidewire (may
have mechanical applications)
• Administration set replacement– 72-96h– More often (1d) for blood product, TPN, fat emulsions
• Hemodyalysis – AV fistula<graft (x2)<catheter (x8.5)
Surveillance
• Monitor site– Visualization of site, palpation of tract if
needed – as clinically indicated
• Record– Standard form for reporting insertion, dressing
change, removal (names, dates, details)
• Culture– Do not culture tips routinely
Nosocomial Pneumonia
• Most common mechanism- aspiration
• Hospital acquired organisms colonize the stomach, pharynx, endotracheal tube
• In many cases VAP 2nd to endotracheal tube and manipulations
Nosocomial pneumonia Pathogens:
• Mostly GNR:– Enterobacter spp.– Pseudomonas aeruginosa – Klebsiella spp
• Gram-positive– S. aureus– S. pneumonia
Preventing Measures
• Body position
• Ventilator intervention
• Stress-ulcer prophylaxis (non-acid reducing agents)
• Selective decontamination- avoid
• Reduce invasive devices
• Improve patient condition- nutrition
UTI
• Associated with urinary catheters
• Is it required
• Minimizing duration
• Care of catheters
• Patient to patient transmission
• Closed systems