MRSA Surveillance: to report or not to report

Dr Bonnie HenryBC Centre for Disease Control

Surveillance Definition

Surveillance is the ongoing, systematic collection, analysis, and interpretation of health data essential to the planning, implementation and evaluation of public health practice, closely integrated with the timely dissemination of these data to those who need to know. The final link in the surveillance chain is the application of these data to prevention and control.

Elements of a Surveillance System

1. Data collection: pertinent, regular, frequent, timely - i.e. ongoing and systematic

2. Consolidation and interpretation: orderly, descriptive, evaluative, timely

3. Dissemination: prompt, to all who need to know (data providers and action takers)

4. Action to control and prevent

WHO, 2000

Health Care System Public Health Authority

Intervention Information

Event Data

Decision

(Feedback)

Reporting

Analysis & Interpretation

Surveillance: A Classical Model

Surveillance is NOT the same as:

Disease reporting - reporting provides a foundation for surveillance

Monitoring or Screening - monitoring and screening do not involve planning, implementation and evaluation

Objectives of Surveillance Systems:

1. Monitor trends 2. Understanding of diseases and

their determinants 3. Identify and predict clusters,

outbreaks, threats to health and emerging issues

4. Detect changes in health practices

Objectives of Surveillance Systems cont.:

5. Facilitate epidemiological research6. To assist with planning and policy7. Empower individuals, health

providers, governments and communities with the information necessary for them to take action to protect and improve health

Types of Surveillance

Active Passive Enhanced Sentinel

Rationale for Surveillance System Development

•  Disease Importance• Impact – burden of disease, PAR of risk factor,

severity, societal impact• Communicability – for infectious diseases

•  Intervention• Prevention / Control - ability to intervene effectively• Immediacy of response – needed to control spread or

severity•  System

• Requirement for reporting – legislated or international interest

• Public perception – concern about risk

Why conduct healthcare surveillance?

• Determine baseline rates of HAIs• Detect time/space clustering (ie, outbreaks)• Detect changes in rates and/or their distribution• Identify areas for targeted investigation and/or

research• Determine the effectiveness of IC measures• Monitor compliance with established hospital

policies and practices

Why conduct healthcare surveillance cont’d?

Evaluate changes in practice Meet regulatory and other reporting

requirements Generate hypotheses concerning risk factors Guide treatment and/or prevention strategies Reduce healthcare associated infections Support evidence-based resource allocation

Targeting your surveillanceFocus on:

• Preventable infections• Frequently occurring infections or events• Infections that cause significant morbidity or

mortality• Infections that are costly to treat• Infections caused by organisms resistant to

multiple antimicrobial agents

Lautenbach E & Woeltje K. eds. Practical Handbook for Healthcare Epidemiologists.

Thorofare, NJ: SLACK Incorporated; 2004.

History of Reporting

• Nationally Notifiable Diseases have been reviewed in 1988, 1997-8 and in 2006

• Framework and criteria developed for the 1997 process

• Provincial review in some provinces• Number of diseases added to or removed

from BC list over time including MRSA• Historically there has been no formal

framework or process for adding or removing from list in BC

Criteria for Reportability

1. Diseases of Interest to Organizations to Inform Prevention and Regulatory Programs

2. 5-Year Average Incidence

3. Severity4. Communicability/

Potential Spread to the General Population

5. Potential for Outbreaks

6. Socioeconomic Burden

7. Preventability8. Risk Perception9. Necessity of Public

Health Response10. Increasing or

Changing Patterns

MRSA in the USA

Approximately 32% (89.4 million persons) and 0.8% (2.3 millions persons) of the U.S. population is colonized with S. aureus and MRSA respectively. (Kuehnert MJ et al. Journal of Infectious Diseases. 2006;193:172-9.)

The proportion of healthcare-associated staphylococcal infections that are due to MRSA has been increasing: 2% of S. aureus infections in U.S. intensive-care units were MRSA in 1974, 22% in 1995, and 64% in 2004. (Klevens RM et al. Clinical Infectious Diseases 2006;42:389-91)

There are an estimated 292,000 hospitalizations with a diagnosis of S. aureus infection annually in U.S. hospitals. Of these approximately 126,000 hospitalizations are related to MRSA. (Kuehnert MJ et al. Emerging Infectious Diseases. 2005;11:868-72.)

MRSA in Canada• 1981: MRSA first reported in Canada

• Subsequently MRSA identified in many Canadian health care facilities

• 1987-1990: CA-MRSA described in Aboriginal communities

• 1995: Nationwide data available in Canada• National MRSA surveillance started in sentinel

hospitals• 2001: Canadian Nosocomial Infection

Surveillance Program (CNISP) summary of first five years of surveillance

CNISP Surveillance

GOALS AND OBJECTIVESThe objectives of this surveillance project

are as follows:1. To determine the incidence and burden of

illness associated with MRSA in CNISP hospitals.

2. To describe the epidemiology of MRSA in Canada.

3. To characterize the molecular strains of MRSA in Canada.

CNISP MRSA Surveillance

• Between 1995 and 2003, MRSA rates increased in CNISP hospitals from 0.46 cases per 1,000 admissions to 5.10 per 1,000 admissions (p = 0.002)

• Most of the increase in MRSA cases occurred in central Canada (Ontario and Quebec), although there were also increases elsewhere in the country

Ref: Simor, 2001: CMAJ

Regional MRSA rates in Canadian

hospitals, 1995-2003

Cost of MRSA

Direct health care cost attributable to MRSA in Canada, including cost for management of MRSA-infected and -colonized patients and MRSA infrastructure, averaged $82 million in 2004 and could reach $129 million in 2010.

MRSA is a costly public health issue that needs to be tackled if the growing burden of this disease in Canadian hospitals and in the community is to be limited.

Source: Canadian Journal of Infectious Diseases and Medical Microbiology, Volume 18, No. 1, January/February 2007

MRSA in BC(Hospital Separation data)

Incidence of MRSA Diagnosis in Acute CareBritish Columbia

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BC 29.99 33.78 32.91 45.13

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MRSA – As a Proportion of S. aureus Isolates (BC – AMM)

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% MRSA

Percent

MRSA: Community vs Hospital

Community-Associated Methicillin-Resistant Staphylococcus aureus (CA-MRSA)

Reports began in 1980s of MRSA occurring in the community in patients without established risk factors Younger patients Indigenous peoples and racial minorities Skin infections common Outbreaks:

Injection drug users Players of close-contact sports Prison/jail inmates Group Homes (developmentally disabled) Men who have sex with men

CA-MRSA vs HA-MRSA isolates

CA-MRSA HA-MRSA

Antimicrobial resistance

Few Agents Multiple Agents

SCCmec* Type IV Type II

PGFE Types USA 300, 400(CMRSA 10)

USA 100, 200

PVL Toxin Common Rare

*genetic element carrying mecA resistance gene Ref: CDC

Reasons to Report

A growing community-based problem caused by a communicable disease with some family based clustering

No other good mechanism to track the problem

What is its magnitude? Distribution? Is it changing for the better or worse?

Advice for patients, contacts, household members may benefit from systematic delivery

If yes, what case definition?

Epidemiological Definition?

Phenotypic Definition (R Profile)?

Genetic Definition?

What are We Actually Doing?

Surveillance - reportable in some provinces

Laboratory Reference Work - many provinces

Guidelines (national and local) Prevention - e.g. Do Bugs Need

Drugs Studies at various sites CCHSA requirements

Issues

Need to establish surveillance for HAIs BUT

Will making it reportable help? What about public reporting of rates? How do we distinguish CA and HA-MRSA? What about reporting of invasive disease

only or reporting of aggregate rates?

Conclusions

Development of surveillance systems for HAI a priority in BC

Need to have connections with Public Health to address the spectrum of illness (we are all in this together!)

Work together to address both needs and to protect patients, HCWs and our community.

Discussion!

Thank you!Bonnie.henry@bccdc.ca