2010 - MRSA Surveillance Protocol

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Table of Contents

• Introduction
• Objectives
• Methodology
• Appendix 1 - List of CHEC Sites
• Appendix 2 — Algorithm for 2010 MRSA Surveillance
• Appendix 3 — Screening Data Submission Form 2010 Surveillance of Methicillin Resistant Staphylococcus aureus (MRSA) for Screening Isolates
• Appendix 4 — Sample Line List
• Appendix 5A — Patient Questionnaire 2010 Surveillance of Methicillin Resistant Staphylococcus aureus (MRSA) for Cases Identified as Clinical Isolates or Blood Culture Isolates
• Appendix 5B — Complete for New 2010 MRSA Cases Identified as a BLOOD CULTURE ISOLATE
• Appendix 6 — Data Dictionary - definitions and notes SCREENING DATA SUBMISSION FORM
• Patient Questionnaire Part A – Clinical Isolate
• Part B – Blood Culture Isolate

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Introduction

Prior to 1995, national data describing the incidence and epidemiology of MRSA in Canada were not available. In 1995, national surveillance for MRSA was started in sentinel hospitals participating in the Canadian Nosocomial Infection Surveillance Program (CNISP) and has been ongoing.

The Canadian Nosocomial Infection Surveillance Program (CNISP) is a collaborative effort of the Canadian Hospital Epidemiology Committee (CHEC), a subcommittee of the Association of Medical Microbiologists and Infectious Disease (AMMI) and the Centre for Infectious Disease Prevention and Control (CIDPC) of the Public Health Agency of Canada. 

Established in 1994, the objectives of CNISP are to provide rates and trends on healthcare-associated (nosocomial) infections at Canadian health care facilities thus enabling comparison of rates (benchmarks), and providing evidence-based data that can be used in the development of national guidelines on clinical issues related to healthcare-associated infections.  As of 2007, 51 sentinel CHEC sites (which may be networks of more than one hospital), with 8 paediatric stand alone sites and 29 CHEC members from 9 provinces participate in the CNISP network.

CHEC members participate in CNISP by working on sub-committees that direct the development, implementation and analysis of surveillance projects in CNISP.   CHEC hospitals will often have Infection Control Professionals (ICP) representatives sitting on these committees. CHEC members participate voluntarily in CNISP projects by collecting standardized, case-by-case, non-nominal data on hospitalized patients.  The data is submitted to CNISP for compilation and analysis.

MRSA data collected for the calendar year 2009 will reflect all "newly-identified" MRSA cases from the CHEC hospitals.  However, colonized MRSA cases that are identified in screening and prevalence surveys or during outbreak investigations are reported as aggregated data only.  If these cases should develop an MRSA bacteremia, or another site of MRSA infection, cases will be updated from colonization to infection, but only be counted once.  The intent is for cases to be updated should the ICP become aware of a colonized case that has developed an MRSA infection; however, actively following colonized cases is not expected.

Objectives

The objectives of this surveillance project are to:

1. describe the burden of disease associated with MRSA in Canadian hospitals, participating in the CNISP
2. determine the annual incidence of MRSA in Canadian hospitals, participating in CNISP
3. determine MRSA bacteremia rates (as an indicator of the burden of disease and MRSA reservoir) in Canadian hospitals, participating in CNISP
4. characterize all bloodstream MRSA isolates, and a subset of clinical MRSA isolates recovered from CHEC/CNISP hospitals, by antibiogram, molecular typing, and SCCmec typing.

Methodology

MRSA surveillance inclusion criteria

MRSA case definition:

• isolation of Staphylococcus aureus from any body site

AND

• resistance of isolate to oxacillin

AND

• patient must be admitted to the hospital

AND

• is a "newly identified MRSA case" at a CHEC facility at the time of hospital admission or identified during hospitalization.

This includes:

• MRSA cases identified for the first time during this hospital admission
• Cases that have been previously identified at other non-CHEC sites (since we want newly identified MRSA cases at CHEC sites)
• Cases that have already been identified at your site but are new cases.  This can only be identified if the previously identified case has another strain.  This means the person was exposed again to MRSA and acquired another strain of it from another source (a new Patient identifier should be assigned only if it is an MRSA infection, identified as a clinical isolate or bacteremia).

This DOES NOT include:

• MRSA cases previously identified at other CHEC sites (See Appendix 1 for list of CHEC sites)
• Emergency, clinic, or other outpatient cases
• Cases re-admitted with MRSA (unless it is a different strain)

Healthcare-associated case definition:
Once the patient has been identified with MRSA, they will be classified as healthcare-associated based on an assessment of the practitioner using the following criteria:

• length of time in hospital prior to MRSA identification (> 48 hours)
• knowledge of previous MRSA status
• date of admission
• length of stay in hospital
• prior hospitalization or other healthcare facility history (previously admitted in past 12 months)
• where patient admitted from (e.g., long-term care)

Newborn healthcare-associated case definition:
A MRSA case in a newborn may be considered as healthcare-associated if the mother was not known to be a case on admission and where there is no epidemiological reason to suspect that the mother was colonized prior to admission, even if the newborn is < 48 hours of age.  In the case of a newborn transferred from another institution, MRSA may be classified as healthcare-associated if the organism was not known to be present and there is no epidemiological reason to suspect that acquisition occurred prior to transfer.

Community-associated case definition:
Community-associated cases are defined as meeting all of the following criteria:

1. no previous known MRSA
2. MRSA identified ≤48 hours after hospital admission
3. no hospitalization in the previous 12 months
4. no surgery or dialysis in the previous 12 months
5. no residence in a long-term care facility in the previous 12 months
6. no indwelling catheter or medical device (e.g. foley catheter, IV line, tracheostomy, feeding tube)

Data Collection
Surveillance for MRSA is laboratory-based.  Upon laboratory identification of MRSA from an in-patient for the first time, the ICP is to be notified.  There are three levels of surveillance that will be conducted, requiring different levels of data gathering.

In order to accomplish the objectives, without placing increased demands on hospital ICPs and hospital laboratories, the 3 levels of surveillance will require different levels of data gathering:

(A) Screening specimens (MRSA recovered from nose, perianal, perineal, groin, axillary, or other screening sites:   i.e., colonization)

(B) Clinical (non-screening specimens), not including blood culture, isolates (ie, infection)

(C) Blood culture isolates (i.e., infection)

NOTE: A patient can only be counted once, and when possible, should default to the highest level (i.e. in descending order:  blood culture isolate; clinical isolate; screening isolate).  Therefore, data submitted to CNISP should be updated, when possible, if an initially colonized patient subsequently develops an MRSA bacteremia, or another site of MRSA infection (noting that for calculating rates, the patient is counted only once).  Although there is NO timeframe for following MRSA colonized patients to determine if they subsequently develop an infection, should the ICP become aware that an infection has occurred in a previously colonized patient, the database should be updated.
An algorithm (Appendix 2) has been provided to assist the ICP in surveillance activities.

(A) Screening Isolates

For cases identified by MRSA screening isolates, a line-list of cases identified will be recorded by the ICP along with the site of MRSA acquisition.  The ‘Screening Data Submission Form’ (Appendix 3) will be used to submit the aggregate data (the total number of cases identified and the numbers attributed to each site of acquisition) on a quarterly bases indicating the surveillance period, and date of data submission.  Count the number of new MRSA cases identified by screening specimens, and only note the site of acquisition – i.e.(i) healthcare-associated, your institution; (ii)  healthcare-associated, another institution; (iii) healthcare-associated, long-term care facility (LTCF); (iv) another healthcare exposure; (v) community-associated; (vi) unknown. Maintaining a line list will assist the ICP in tracking the new MRSA cases.  A sample line list is provided (Appendix 4) or one may be developed by the individual CHEC site.  Note that the purpose of the line list is for tracking MRSA by the ICPs, and NOT to be sent in to CNISP. 

Data from the surveillance period between Jan.1 and Mar. 31 will be submitted (Appendix 3) by April 15; data for April 1 to June 30 will be submitted by July 15; data for July 1 to Sept 30 will be submitted by Oct. 15; and data for Oct. 1 to Dec. 31 to be submitted by Jan.15 of the following year.  Each form (Appendix 3) sent in will also require CHEC site # for hospital site identification.

Rates will be calculated using these numbers and appropriate denominators.

B) Clinical Isolates

For each isolate recovered from clinical (non-screening, non-blood culture) specimens the ‘Patient Questionnaire’ (Appendix 5)  Part A only will be completed, in order to determine numbers (rates), and simple clinical information (these are data that ICPs generally already obtain as part of routine MRSA hospital surveillance programs).  The information collected by chart review will include patient demographic and clinical information.   

Data elements will include:

• CHEC site number
• Unique identifier
• Date of birth
• Sex
• Date of admission
• Where MRSA was acquired (healthcare-associated or community)
• Date of positive clinical isolate culture
• Anatomical site of MRSA isolation
• If the patient has or meets criteria for an MRSA infection
• Whether the patient has a necrotizing pneumonia or necrotizing fasciitis due to MRSA

(C) Blood Culture Isolates

For each MRSA bacteremia case, the patient questionnaire (Appendix 5) Part B only will be completed. The information collected by chart review will include patient’s demographic and clinical information, along with additional information on outcome.

Data elements will include:

• CHEC site number
• Unique identifier
• Date of birth
• Sex
• Date of admission
• Where MRSA was acquired (healthcare-associated or community)
• Date the blood culture specimen was obtained
• Date of hospital or in-hospital death
• Whether any positive MRSA screening cultures were taken before the blood culture
• Was the patient epidemiological linked to others within the institution
• What service/unit the patient was on when MRSA bacteremia was acquired
• The probable source of the MRSA bacteremia
• Was the patient admitted to an Intensive Care Unite within 30 following the positive blood culture
• What was the outcome at 30 days from date of positive blood culture

Electronic Data Entry

The WEB S MRSA data entry system has been discontinued and replaced by CN PHI. Please submit all screening aggregate data and individual case forms at www.cnphi-rcrsp.ca. For technical assistance, questions, or comments, please contact Katie Cassidy, using the information listed below. 

Denominator data

To obtain the necessary denominator information for the calculation of national MRSA rates, each participating health care facility will complete a hospital profile on an annual basis and submit this information no later than April 30, 2010.  In addition, to the total denominator numbers, pediatric denominator data are also required. Pediatric cases are defined as ≤ 18 years of age. Data collected on this profile will include:

1. total number of unique Staphylococcus aureus  (S. aureus) isolates tested per year
2. total number of patient hospital admissions per year (separate line for pediatrics)
3. total number of inpatient-days per year (separate line for pediatrics)
4. total number of unique S. aureus blood culture isolates per year.   

Surveillance Period

The 2010 MRSA surveillance period begins on January 01^st and ends on December 31^st , inclusive.

Laboratory surveillance:

The following isolates only are to be saved and sent to the National Microbiology Laboratory (NML) in Winnipeg:

1. All MRSA clinical isolates (NOT screening isolate i.e. nose, perianal, perineal, groin, axillary, or other screening sites) from specimens obtained January 1 – March 31, 2009.
2. All MRSA blood culture isolates (1 per patient) for the surveillance year 2009.
3. All isolates from any patient with a diagnosis of necrotizing fasciitis or necrotizing pneumonia due to MRSA, for the surveillance year 2009.

The IC Ps should notify their lab to save the above-mentioned specimens for the NML. Always notify the NML when specimens are being sent.

(A) Summary of Laboratory Requirements

• The IC Ps are requested to notify their Lab to retain one clinical isolate per questionnaire if:
  • the date of first positive culture is between January 1st – March 31st, 2010 (question 8)
  • there is a diagnosis of necrotizing fasciitis or necrotizing pneumonia due to MRSA (questions 11 & 12)
• Always label the samples using the appropriate suffix ending as defined below.
  • CI = C linical Isolate
  • NP = N ecrotizing Pneumonia
  • NF = N ecrotizing Fasciitis

Contacts

Isolates should be sent to the following address:

Dr. Michael Mulvey
National Microbiology Laboratory
1015 Arlington St.
Winnipeg, Manitoba
R3E 3R2
Tel: 204-789-2133
Use FedEx billing number: 2299-8435-7

For questions regarding data collection, data submission forms and questionnaires, please contact:

Katie Cassidy
CNISP Surveillance Officer
Phone: 613-954-1718
Fax: 613-946-0678
E-mail: katie_cassidy@phac-aspc.gc.ca
Nosocomial and Occupational Infections Section
1408-100 Eglantine Driveway, P.L. 0601E2
Ottawa, Ontario K1A 0K9

Surveillance Period
The 2009 MRSA surveillance period will begin January 1, 2009 and continue to December 31, 2009 inclusive. 

Analysis and Evaluation

Each site will send the aggregated data by mail or fax on a quarterly basis to the Nosocomial and Occupational Infections Section (NOI) of the Public Health Agency of Canada using the screening data submission form (Appendix 3).

For the clinical isolates and the blood culture isolates, the patient questionnaires (Appendix 5) will be completed at the CHEC sites, batched and sent monthly to the Nosocomial and Occupational Infections Section (NOI) of the Public Health Agency of Canada for data entry.

For each site, regionally and nationally, the following rates will be calculated each year:

1. MRSA as a percentage of all (non-duplicate) S. aureus isolates
2. incidence of MRSA cases per 1,000 admissions
3. incidence of MRSA per 10,000 inpatient-days
4. incidence of healthcare-associated  MRSA per 1,000 admissions
5. incidence of healthcare-associated  MRSA per 10,000 inpatient-days
6. MRSA bacteremia rate (as a percent of S. aureus blood cultures)
7. MRSA bacteremia rate per 1,000 admissions
8. proportion of MRSA bacteremias that are healthcare-associated
9. healthcare-associated MRSA bacteremia rates per 1,000 admissions

Regional and national rates only will be published.  The incidence of MRSA among hospitalized patients, geographic trends and descriptive epidemiology of MRSA will be reported via CNISP reports, presentations and publications.

Ethics

While this surveillance project is observational and does not involve any alteration in patient care, ethics approval may be sought at some hospital sites. Surveillance for healthcare-associated infections is a routine component of quality assurance and patient care in Canadian health care institutions and therefore informed consent is not required.  A unique identifier linked to patient name will only identify patients at the local CHEC site and is not transmitted to the Public Health Agency of Canada. All data submitted is kept strictly confidential.

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