MRSA Screening-Non molecular vs molecular testing - Dr Gerri Hall - November 2010 Symposium
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The document discusses the comparison and cost-effectiveness of MRSA screening methods in hospitals, detailing both molecular and non-molecular approaches. It emphasizes the significant impact of hospital-acquired infections, particularly MRSA, which leads to increased costs and mortality, and outlines strategies for prevention and screening. The author shares outcomes from various studies on hospital-wide screening and interventions, highlighting the benefits and challenges associated with different testing methods and their implications for patient care and healthcare costs.
MRSA Screening-Non molecular vs molecular testing - Dr Gerri Hall - November 2010 Symposium
- 1. 11/12/2010 Comparison and Cost Effectiveness of MRSA Screens: Molecular vs. non-molecular methods Gerri S. Hall, Ph.D. Eastern PA Branch, ASM November 18, 2010 hallg@ccf.org CLEVELAND CLINIC Downtown CLEVELAND, OHIO Cleveland Cleveland Clinic Complex CCF: ~ 1000 hospital beds 12 family health centers Medical School Medical Technology School Reference Laboratory OBJECTIVES • TO DISCUSS IMPACT OF HOSPITAL ACQUIRED INFECTIONS (HAI) ON THE CLINICAL MICROBIOLOGY LABORATORY • TO DESCRIBE THE METHODS FOR MRSA SCREENING • TO PRESENT OUTCOMES DATA ON MRSA SCREENING PROGRAMS 1
- 2. 11/12/2010 Conflict of Interest • Speaker for Becton-Dickinson and bioMerieux • Consultant: Opgen, Intelligent MDx • Most recently involved in research with: – bioMerieux – Pocared – Advandx – MicroPhage – Prodesse • Committees/Boards – CLIAC – CAP Microbiology Resource Committee – ASCP Teleconference Committee; RIS Committee – ASMBL: ASM Branch Lectureship Program; CPEP Sit back and relax! Bad Hair Day Feeling trapped Snooze and chewz What are HAI’s • Site & procedure Specific – Bloodstream Infections (BSI) – Urinary Tract Infections (UTI) – Ventilator-Associated Pneumonia (VAP) – Surgical Site Infections (SSI) • Mediastinitis following cardiac surgery • Vascular Surgery • Orthopedic Surgery • Neurologic Surgery • Pathogen Specific – C. difficile – MRSA 2
- 3. 11/12/2010 Reasons for HAI Prevention • Better patient care – HAI‘s affect 1 in 20 patients in US hospitals per year – ~100,000 deaths have been attributed to HAI‘s • Reduced costs to healthcare – ~ $33 billion dollars in excess medical cost • 28 States now mandate public reporting of HAI‘s • Goals of 2009 action plan of Federal government to prevent HAI‘s – Reimbursement will decrease or not exist for HAI ‗s – Present data on HAI‘s do not include non-hospital settings • 26,000 non-hospital healthcare settings • The right thing to do Zero Tolerance to HAI’s • Consumers (patients) want this • CMS wants this • Insurance companies want this • Healthcare workers want this • Is it really possible? – Speaker’s opinion: Probably not realistic to have ―Zero‖ HAI‘s • but we can still work to reduce HAI‘s where and when that is possible Magnitude of the problem: Methicillin Resistant S. aureus • ~293,000 hospitalizations in U.S. annually are diagnosed with S. aureus infections – ~0.8% all hospital discharges – MRSA = ~60% of these SA episodes ~0.3% all hospital discharges MRSA in community (CA-MRSA): unknown incidence but rising • MRSA HAI attributable costs were reported as $35,367 (APIC study 1990-2000; Stone PW et al. AJIC 2002; 30: 145-52) • ISPOR report in 2005 estimated annual cost to treat MRSA in US hospitals was $3.2 – $4.2 billion – Pfizer, Inc. Infect Cont today 2005; – http://www.infectioncontroltoday.com/hotnews/55h168584264313. html. 3
- 4. 11/12/2010 Impact of MRSA • Nosocomial Infections – Associated with prolonged hospital stays, prolonged ICU stays and longer antibiotic associated LOS – Associated with greater costs • Abramson calculated excess attributable cost of $27,083 for MRSA bacteremia vs. $9,661 for MSSA bacteremia • Engemann showed 1.9 fold increase in hospital charges among pts. with MRSA surgical site infections • Leads to higher rates of vancomycin usage thus selecting for vancomycin-resistant pathogens Engemann JJ, et. al. Adverse clinical and economic outcomes attributable to methicillin resistance among patients with Staphylococcus aureus surgical site infection. Clin. Infect. Dis. 2003; 36:592-98. Abramson MA, et. al. Nosocomial methicillin-resistant and methicillin-susceptible Staphylococcus aureus primary bacteremia: at what costs? Infect. Control Hosp. Epidemiol 1999; 20:408-11. Chaix C, et. al. Control of endemic methicillin-resistant Staphylococcus aureus. JAMA 1999; 282:1745-51. ―Superbug‖ publications in medical literature by year 18 16 14 12 10 # Publications 8 6 4 2 0 1988 1991 1994 1997 2000 2003 2006 2009 Modified from Perencevich EN and DM Treise. Infec Control & Hosp Edidemiol. 2010; 31: S48-S50. MRSA: The Hidden Threat Clinical Infections • MRSA colonization is asymptomatic • Reservoirs are mainly skin and nares • Spread occurs from a colonized patient to another, usually via a healthcare worker’s hand Colonized • Goes unnoticed and spreads (asymptomatic) easily Patients Sources: Boyce et al., SHEA 1998, Abstract S74. Zachary et al., ICHE 2001; 22:560-564. Boyce et al., ICHE 1997;18:622. 4
- 5. 11/12/2010 MRSA Screening - Is It Inevitable? ―Search and Destroy‖ European Strategy for MRSA Control ―Search and Destroy‖ • Long-standing, intensive, coordinated campaigns in Denmark, the Netherlands, and some other European countries relies on targeted screening of high-risk patients. – When multiple cases of MRSA are noted, entire units can be closed for comprehensive screening and cleaning – Health care workers are screened for carriage and if colonized, not allowed to work til they are successfully decolonized • Pan et al. ICHE 2005;26:127-33 • Verhoef et al. 1999; EJCMID 18: 461-6 • Vandenbroucke-Grauls et al. 1996; ICHE 17: 512-3 • Kluytmans-Vandenbergy et al. 2005; Infection 33: 309-13. 5
- 6. 11/12/2010 Is U.S. Different from Europe in MRSA Incidence and Screening? • Mean % of cases of SA caused by MRSA in hospitalized patients = 20% – Wide variation in Europe from 1% in some Nordic countries to > 50% in So. European countries • European CDC recently estimated MRSA causes > 171,000 HAI leading to 5400 deaths and > 1 million extra hospital days What are the MRSA programs in Europe 1999-2007? • A combination of the following was identified in Belgium, UK and France: • Structural – Antimicrobial stewardship • ―prudent use of antibiotics‖ committees developed – Dept. of Health Improvement team visits – Increased funding for ICP‘s and antibiotic managers • Regulatory – Mandatory reporting of MRSA BSI rate – Mandatory participation in MRSA surveillance • General Infection Control – Hand hygiene and campaigns for it – Care ―bundles‖ • MRSA Control – MRSA control guidelines – MRSA BSI reduction target goals of ~ 50^ Decreasing trend in % of SA bacteremia caused by MRSA in 10 European Countries 70 Austria %mrsa/sa BACTEREMIA 60 France 50 Israel 40 Latvia Romania 30 Belgium 20 Ireland 10 Italy Poland 0 UK 2005 2006 2007 2008 Struelens MJ et al. Inf Cont Hosp Epidemiol 2010; 31: S42-44 6
- 7. 11/12/2010 MRSA Detection & Prevention High-risk or infected patients All hospital • ICU admissions • Surgical • Burn unit • NICU MRSA High-risk Frequent admissions hospital visits • ER • Dialysis • Hospital transfer • HIV • Nursing home • Long-term care • Screening programs can be effective for various groups of patients Laboratory Screening for MRSA • Conventional Culture – Culture on blood agar; incubate overnight; pick colonies consistent with S. aureus; do a catalase and coagulase for confirmation; set up MIC and read results next day – Time range for report: 2 days; most work; least specific; ?? Quite sensitive, although not necessarily the most sensitive method. – Culture on ―selective media‖ ex: Mannitol salt agar (MSA) • S. aureus colonies will be yellow next day; prove ID and do an MIC as above – Time range for report: 2 days; more selective, but less sensitive • Culture on Selective MRSA Chromagar – Culture onto agar that detects MRSA by growth and a color change in the media; > 4 commercial manufacturers – Requires 24-48 hrs for detection; up to 85% in first 24 hrs can be detected for most of the Chromagar – Chromagar comparison: Yang HY et al. Ann Cin Lab Sci 2010; 40: 252-6 Remel Spectra MRSA BioRad MRSA Select ChromID MRSA from BD CHROMagar MRSA bioMerieux: green colonies 7
- 8. 11/12/2010 Laboratory Screening for MRSA: Molecular Methods • Molecular Methods for detection – Detection of MRSA directly in the clinical samples (nasal swab) • BD GenOhm MRSA Assay (Becton Dickinson) – Specimen processing manual; automated read— about 1 ½ to 2 hrs; with 2 Smart Cyclers, can run ~25 samples in this time • Xpert MRSA Assay (Cepheid) – Minimal processing; automated read; single tests can be run; batching not required; each run is about 75 min., so total time for a sample would be about 1 ½ hr. • Roche ASR: on Light Cycler – Detection of MSSA and MRSA in nasal swabs by both BD GenOhm and Cepheid GenXpert: can also be used for positive blood cultures as well. The SmartCycler • Random Access to each I-CORE module • Amplification and detection in single step • Closed-tubes minimize contamination Rapid, Easy, Test Set Up (per Cepheid) 5. 8
- 9. 11/12/2010 MRSA Screening: comparison of GenOhm and GeneXpert vs. Broth-enhanced culture Sensitivity Specificity PPV NPV PPV After resolution GenOhm 100% 98.5% 100% 82- 93- 87%* 94%* Xpert 100% 98.2% 100% 67- 89- 93%* 92%* • 425 patients: 414 nasal and 389 groin swabs (378 patients with both) • * range represents nasal and inguinal alone or the two combined – Hombach M et al. JCM 2010; 48: 3882-7 MRSA Screening: comparison of GenOhm and GeneXpert vs. Broth-enhanced culture • Authors conclusion: – Both assays performed well – Combining nasal and groin increases rate of detection – Increased inhibition with taking samples from other sites than nares and groin – NPV excellent, thus back-up cultures unnecessary – Back-up cultures for + may be needed due to low PPV • However PCR may ne new gold standard – Xpert MRSA had better TAT than BD GenOHM Time to Detection of MRSA Summary of Various Screening Methods Method Time Required (hours) SAB > 48 MSA ~72 SBA + oxacillin > 48 Enrichment broth/PNA 5 h plus MRSA FISH confirmation CHROMagar MRSA 24-48 PCR < 2.5 h 9
- 10. 11/12/2010 Costs of Molecular vs Non- Molecular testing • Everyone‘s instrument and reagent costs vary as do the salaries and benefits of laboratory personnel – Non-molecular • 0.20 for a BAP vs. 0.50 for a MSA vs. $4- $5 for a MRSA selective Chromagar • + cost, if needed of the disk or other AST assay if done – Molecular (wide variance if home-brew or purchased) • $30,000 - $75,000 for equipment • $25-30 or more per test for reagents » Diekema DJ and MB Edmond CID 2007; 44: 1101-7. What will be done with the MRSA Screening Results? • Test for MRSA only or MSSA and MRSA • If Positive for whatever of the above: – Mupirocin will be employed in the nares for • Prevention of infection in patient • Prevention of transmission of one patient to another and/or – Patients will be isolated to prevent transmission and/or – Data is being collected : • To determine prevalence • To report MRSA in your hospital • To know results in an individual patient for future care • WHAT IS DONE WITH THE DATA WILL HAVE TO GO INTO THE DECISION OF WHAT TEST TO USE FOR SCREENING ! Outcomes data I found and would like to Share 10
- 11. 11/12/2010 Evanston Hospital Experience • Developed a strategic plan to implement total hospital admission screening for MRSA using the BD GeneOhm assay and have been doing this starting in August 2005 – 40,000 annual admissions (850 bed complex) – 100 samples/day, 7 days per week – MRSA + patients are decolonized and placed into isolation: • 5 days mupirocin • Chlorhexidine baths day 1, 3, and 5 – Have been able to demonstrate: • a reduction in serious MRSA infections • Reduction in MRSA respiratory infections • Very little mupirocin resistance • Cost savings above cost of the program: $300,000 to $1 m. Rapid MRSA screening and pre-emptive contact isolation for control of MRSA in critical care unit • Multiplex PCR used in 2 adult ICU‘s in Switzerland 2003- 2005 – Prevalence of previously unknown MRSA carriage was high at ICU admission – Only a small number of pts had their first MRSA from a clinical culture – Rapid PCR permitted significant reduction in TAT: from 4 days to 1 day, as compared to culture – No effect on MRSA rates in SICU, but many pre-emptive isolation days could have been saved – Substantial decrease in MRSA infection in MICU after linking rapid PCR result to pre-emptive isolation and cohorting of MRSA pts. • Harbarth S et al. Critical care 2006; 10: R25 Rapid MRSA Screening in General Hospital Wards: UK study • Cluster randomized crossover trial that compared PCR with culture – rapid MRSA screening for MRSA on admission did not reduce MRSA rates on general wards where pre- emptive isolation was in place – An impact was found on isolation and barrier nursing, but formal cost effectiveness analysis was not done • Did not feel increased costs would be justified • Jeyaratnam D et al. Br Med J 2008; 336: 927-30 11
- 12. 11/12/2010 Screening Plus Intranasal Mupirocin and Chlorhexidine Bathing IN ICU • All patients in Medical-coronary ICU were screened for MRSA and if colonized: – Intranasal mupirocin was administered – Daily chlorhexidine bathing • 52% decrease in colonization and ―infection‖ • Mupirocin resistance remained low (4.4%) • Chlorhexidine resistance did not appear • Ridenour G et al. Infect Cont Hosp Epidemiol 2007; 28: 1155-61. 7 year experience with MRSA Surveillance (Culture) in NICU • 8/2000-8/2007: 7997 infants admitted – 102 (1.3%) positive (infection or colonized) • 2000: 1.79 cases/1000 pt days – 0.15/1000 pt days in 2005 to 1.26/ 1000 pt days in 2007 • 15% had invasive infection: no difference between infected and colonized identified • 14 different antibiograms for MRSA identified • 20002004: mainly HA-MRSA • 2006-2007: mostly Ca-MRSA – 19,090 screening cultures • $1,500,000 not billed to insurers ($71 for ID and $91 for AST) » Gregory et al. Pediatrics 2009; 123: e790-6. Use of Statistics and Models for Outcomes of MRSA Screening • Cardiac Surgery – Routine pre-op MRSA screening provides substantial economic value to 3rd party payers and hospitals over a range of MRSA colonization prevalence rate, success levels and surveillance costs • Lee BY et al. Am J Managed Care 2010; 16: e163-73. • Orthopedic Surgery – Pre-op screening and decolonization was strongly cost-effective from 3rd party payer even with MRSA prevalence as low as 1%, or decolonization success was as low as 25% and decolonization costs were as high as $300. From hospital standpoint, MRSA screening and decolonization was economically dominant strategy for all scenarios explored 12
- 13. 11/12/2010 Cardiac Surgery SA Screen Surgical Prophylaxis PCN Allergic Negative Positive Or Aorta Case Yes No Mupirocin Cefuroxime Vancomycin Aztreonam MRSA Carrier? Surgical Prophylaxis If Yes Add Vancomycin Is MRSA Screening necessary? • Australian study to decrease burden of endemic MRSA in ICU (8.5 yr retrospective study)- – 2000 admissions/year; no active screening or contact isolation done – Regression modeling to evaluate trends in SA prevalence density, antibiotic consumption, infection control consumables, alcohol-based hand run solution (ABHRS) • Results – MRSA decreased by 83% – Rates of MRSA BSI decreased 89% • No changes in MSSA bacteremia – Hospital MRSA prevalence decreased 17% – Antibiotic usage decreased 26% in ICU coinciding with decrease in MRSA • Decrease in MRSA associated with ABHRS—but introduced late in study after MRSA declines seen • Conclusion: General QI measures were associated with decrease in endemic MRSA in high-risk setting without resource intense active surveillance and isolation practices. – Ananda-Rajah MR et al. Intensive Care med 2010; 36: 1890-8. Knowledge Gaps related to New Interventions to Prevent MRSA • Better understanding of colonization and transmission including inter-facility transmission across the spectrum of health care • Control of antibiotic use • Effective vaccine targets – From: Frieden, TG (CDC Director). • Infec Control Hosp Epidemiol 2010; 31: S1-S3. 13
- 14. 11/12/2010 PCR vs. Culture What’s a Lab to Do? Culture PCR • Relatively inexpensive • May be more expensive • No special training • May require special • Isolate available for training epidemiological studies • Still requires culture if • High throughput isolate is desired possible • Some platforms have • Slow--not practical for: limited throughput – Pre-surgical • Rapid--useful for: screening – Pre-surgical – Pre-emptive screening isolation – Pre-emptive isolation What does a Hospital DO about active surveillance for MDRO/HAIs? • Prepare the Laboratory – Start with one organism and get that going • Focus on all aspects of the Intervention • Measure Meaningful Outcomes • Discuss Impact on Infection Control Program • Diekema and Edmond 14
- 15. 11/12/2010 Who Pays for Surveillance Cultures and Programs? • Patients as part of a ― standard of care‖ • The Microbiology Laboratory • Infection Control departments • Hospital Administration • Other • Sometimes it will just have to be done! Hand Hygiene: an essential piece of any Prevention programs • MRSA rates have fallen off over the past rates in many US hospitals: – Nasal Screening – Rapid PCR methods – Isolation – Chlorhexidine baths – NasalMupirocin – Hand Hygiene efforts – All of the above • Canadian study: systematic hand hygiene of patients and relatives was found to be an inexpensive and highly effective preventive measure against nosocomial transmission. Thanks • Dr. Alan Evangelista for asking me to speak • Pennsylvania ASM Branch for inviting and supporting me today • You, the audience • Medical technologists who do such a great job at laboratory surveillance and detection • Infection Control Practitioners who do such a great job to help prevent and reduce infections 15
- 16. 11/12/2010 Websites • www.apic.org/Content/NavigationMenu/Ed ucation/Online learning/webinars/070110_robicsek.pdf: data in powerpoint from Evanston Hospital assumptions • www.aacc.org/AACC/publications/cln/2007 /august/cover1_0807.htm (Clin Lab News) Wishing you Successful outcomes! Wash your Hands and Have a Great Day! 16