Hospital Authority Convention 2007

Control of Methicillin-ResistantStaphylococcus Aureus

in a Chest Hospital

Dr. KC Wong 1,2, Ms. SM Ling 2, Dr. YC Chan1, Ms. MC Chan 21Tuberculosis and Chest Unit2Infection Control TeamTWGHs Wong Tai Sin Hospital8th May 2007

Introduction (1)

- Methicillin-resistant Staphylococcus aureus (MRSA) first isolated in UK in 1961

- An important nosocomial pathogen in hospitals worldwide

- Individual infection & infection outbreak

Introduction (2)- MRSA endemic in local hospitals- Highly prevalent at Wong Tai Sin Hospital:

*Department of Rehabilitation and Extended Care*Tuberculosis and Chest Unit

- Preponderance of chronic patients: poor functional status, dependent ADL, increased LOS, antibiotic therapy and prior hospitalization last 3-6/12

Control of MRSA Important (1)- Substantial morbidity and mortality of

nosocomial MRSA infections- Potential threats of more resistant pathogen:

* Vancomycin Intermediate Staphylococcus aureus (VISA)

* Vancomycin Resistant Staphylococcus aureus (VRSA)

- First VISA identified in 1995

Control of MRSA Important (2)

- Limited number of antibiotics available for treatment

- Costs of treatment of MRSA infections & implementation of infection control measures

- Linezolid: newer effective antibiotic, unit cost more than 20 x Vancomycin

Infection Control IcebergMRSA isolates from clinical specimens

Cross Transmission

Asymptomatic patients with unrecognized colonization of MRSA

Nursing Home Patients

Transfers

Readmission

New Infection Control Policy in 2001 (1)(Tuberculosis & Chest Unit, Wong Tai Sin Hospital)

- Active surveillance and immediate “isolation” of high risk patients for MRSA on hospital re-admission(Targeted surveillance culture & pre-emptive “isolation”)

- High risk patients defined as patients known to have MRSA in previous admission

New Infection Control Policy (2)(Tuberculosis & Chest Unit, Wong Tai Sin Hospital)

- Evidence-based guideline by Society for Healthcare Epidemiology of America (SHEA): Similar policy of active surveillance cultures (ASC) for patients at high risk for carriage for MRSA (Infection Control & Hospital Epidemiology, May 2003)

New Infection Control Policy (3)(Tuberculosis & Chest Unit, Wong Tai Sin Hospital)

- Management of Multidrug Resistant Organisms in Healthcare Settings 2006 (HICPAC, Centre for Disease Control & Prevention) : ASC also recommended

- Papia et al. Patients with previous Hx of MRSA colonization much more likely to be MRSA screening positive on re-admission (OR, 13.1, P:0.05) [Infection Control & Hospital Epidemiology, July 1999]

Containing the Iceberg(Targeted Surveillance & Pre-emptive “isolation” on Re-admission)

NosocomialMRSAInfectionMRSAColonization

MRSA isolates from clinical specimens

Asymptomatic patients with unrecognized colonization of MRSA

Active Surveillance & immediate “Isolation” (1)

- A continuously updated master name-list of all patients known to have MRSA in previous hospitalization(s) is compiled by Infection Control Team

- Hospital admission officer checks for history of MRSA by this master name-list against the scheduled daily admission

Active Surveillance & immediate ”Isolation” (2)

- Active surveillance cultures & pre-emptive application of contact precautions in patients known to have MRSA in previous hospitalization(s), immediately upon hospital re-admission

- Screening cultures: anterior nares, bed-sores and previous body sites of MRSA isolate

Annual MRSA Incidence 1998 -2005(Tuberculosis & Chest Unit, Wong Tai Sin Hospital)

Year Incidence of New MRSA Patient per 1,000

Admission p-value#

1998 16.66 -

1999 11.06 -

2000 12.68 -

Average of 1998 - 2000 (Reference)

13.14 -

2001 Active surveillance and immediate isolation of patients high risk for MRSA re-admission

2002 10.99 0.255

2003 7.98 0.03

2004 7.33 0.003

2005 7.81 0.006

Average of 2002 - 2005 8.71 < 0.001

# Testing the incidence rate of each year against the reference (average of 1998 - 2000).

MRSA Screening Patients(Wong Tai Sin Hospital)

No. of new MRSA Patients No. of MRSA patients re-admitted WTSH

Year WTSH acquiredOther Hospitals

acquired Total +ve Screening -ve Screening Total

2000 148(70%) 64(30%) 212 - - -

2001 125(55%) 104(45%) 229 - - -

2002 174(66%) 89(34%) 263 14(50%) 14(50%) 28

2003 99(61%) 63(39%) 162 20(71%) 8(29%) 28

2004 134(62%) 82(38%) 216 39(61%) 25(39%) 64

2005 116(50%) 118(50%) 234 60(52%) 56(48%) 116

1. MRSA screening began in 2001 in Tuberculosis & Chest Unit

2. MRSA screening in whole hospital since 2004

3. SARS outbreak in 2003

Milestones of MRSA Control (1)(Tuberculosis & Chest Unit, Wong Tai Sin Hospital)

1999 * Infection Control Link Nurses

2001 * Policy of “Active surveillance & immediate ‘isolation’ of high riskpatients for MRSA on hospital re-admission”

Milestones of MRSA Control (2)(Tuberculosis & Chest Unit, Wong Tai Sin Hospital)

2003 * Post-SARS outbreak: - 6-bed cubicles; 4-bed, 2-bed and

single isolation rooms withindependent ventilation

- 3-feet spatial separation betweenbeds

Milestones of MRSA Control (3)(Tuberculosis & Chest Unit, Wong Tai Sin Hospital)

2004 * Advocate use of alcohol-based hand rub for hand anti-sepsis

* Policy of “Active surveillance & immediate ‘isolation’ of high risk patients for MRSA on re-admission endorsed / implemented for the whole hospital

0

5

10

15

20

1998 1999 2000 Ave ra ge of

1998 - 2000

2001 2002 2003 2004 2005 Ave rage of

2002 - 2005

Per 1 ,000 admission

Annual Incidence MRSA 1998 – 2005(Tuberculosis & Chest Unit, Wong Tai Sin Hospital)

ICLNs

Active surveillance & pre-emptive isolation of patients high risk for MRSA on re-admission

Post SARS isolation facilities

Alcohol-based hand rub

P=0.

030

P=0.

255

P=0.

003

P=0.

006

P<0.

001

Ref

eren

ce

Annual MRSA Incidence 1998 -2005(Department of Rehabilitation & Extended Care,

Wong Tai Sin Hospital)

Year Incidence of New MRSA Patient per 1,000 Admission

1998 26.00

1999 22.27

2000 25.37

2001 20.97

2002 28.41

2003 26.48

#2004 28.75

2005 23.16

# Policy of "Active surveillance & immediate ‘isolation’ of high risk patients in hospital re-admission " implemented since 2004

Conclusions

- Active surveillance & pre-emptive “isolation” of high risk patients contribute to MRSA control even in endemic wards

- Our experiences concur with what are reported in literature

Thank you for your attention