Jurai Wongsawat, M'D'

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MRSA Infection control outbreak investigation

• Jurai Wongsawat, M.D.
• Bamrasnaradura Institute
• Nonthaburi, Thailand

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Outlines

• Mechanism of transmission
• Prevention Control
• Outbreak investigation

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Staphylococci

• Hardiest non spore forming bacteria
• Relatively heat resistance
• Can survive in environmental for several months
• Children and adult up to 25 can be colonized

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High risk - Colonization

• HOST
• Hemodialysis/ CAPD
• Injection drug users
• Dermatologic diseases
• DM
• Those who required repeated injections
• Liver disease
• HIV or other defect immune function
• Nasal abnormalities

• OTHER FACTORS
• Presence of invasive device
• Prior antimicrobial therapy
• History of antecedent colonization
• Increase chance of exposure - HCWs

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Modes of transmission

• Mainly via direct contact
• - hands of HCWs
• Indirect contact
• - clothes, environmental surface,
  equipment
• Airborne transmission
• - Staph pneumonia

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Special problems

• Epidemic vs endemic MRSA
• Community acquired
• - skin and soft tissue infection
• - positive culture on admission
• or within 48 hours
• Frequent antibiotic use

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Problem of ATB use

• Reducing use of second or third gen.
  cephalosporin can reduce rate of colonization/
  infection
• ( Matsumara H, et al. Burns 199622283-6)
• Reduction use of many broad spectrum B-lactam ATB
  was associated with drop of MRSA cases
• ( Frank, et al. Clin Perform qual Health Care
  19975180-88)
• Significant reduction in monthly number of MRSA
  following decreased use of cephalosporin,
  imipenam, clindamycin, vancomycin
• ( Landman D, et al. Clin Infect Dis
  1999281062-66)

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Outlines

• Mechanism of transmission
• Prevention Control
• Outbreak investigation

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Prevention
Control

• Administrative
• - Surveillance
• - Hand hygiene policy
• - Antibiotic control program
• Engineering
• - Isolation room
• Protective equipments
• - Gown, gloves, mask

• Surveillance
• Isolation or cohort nursing Encourage for hand
  hygiene
• Management of colonizers or carriers
• Tretment of infected patients

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Advocated measures (1)
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Advocated measures (2)
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Surveillance

• Laboratory based
• Line listing of MRSA cases
• Routine screening in patients is not recommended
• Screening for high risk patients
• Screen known cases upon readmission

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Isolation or cohort nursing

• Contact precaution
• Isolation
• - not necessary if routine standard
  practice is in place
• - necessary for
• MRSA respiratory tract infections
• wounds that cannot be
• adequately covered

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Hand hygiene (1)

• The most important measure
• Transmission decreased from 16.9 to 9.9 ( 2.16
  to 0.93 episodes per 10,000 patient days)
• when hand hygiene improved from 48 to 66 (
  Pittet et al)
• Problem low adherence

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Hand hygiene (2)

• The most important measure
• Transmission decreased from 16.9 to 9.9 ( 2.16
  to 0.93 episodes per 10,000 patient days)
• when hand hygiene improved from 48 to 66 (
  Pittet et al)
• Problem low adherence

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Hand hygiene (3)

• A simple 10 second wash with soap and water shows
  an absence of MRSA on 96 of cultured individuals
  hand (Simmons B, et al)
• Alcohol based hand rub
• - increase compliance

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Management of colonizers or carriers

• Consider during the outbreak
• More likely to transmitt
• - skin lesion/dermatitis
• - persistent nasal carriage
• Nasal screening
• - endemic with serious infection
• - outbreak

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Decolonization

• 2 mupirocin intranasal
• Rifampin 600 mg bid for 5 days
• Ciprofloxacin 750 mg bid for 14 days
• Combination drug
• High rate of recurrence at 1 mo

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Treatment of infected patients

• Parenteral glycopeptide therapy
• Serum concentration should be monitored

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Outlines

• Mechanism of transmission
• Prevention Control
• Outbreak investigation

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Approach

• Surveillance
• problem, cluster
• Determine existence of an outbreak
• - define case, compare preepidemic
• Epidemiologic study
• - line listing, epidemic curve, risk factor
  study
• ( case control/ cohort)
• Additional studies
• - reviews, culture surveys, isolate typing
• Interventions/ control measures
• Assess interventions

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Elimination of Epidemic MRSA from a University
Hospital and District Institutions, Finland

• August 1991 October 1992, two outbreaks in
  surgery medicine
• Screening policy after cases occurred
• - all pts, contact HCWs
• - nasal swab other sites
• after 2 neg results individuals were no
  longer screened
• Subsequent admission
• - screen and isolate

Kotilainen P, et al. Emerg Infect Dis 20039
169 -75)
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Elimination of Epidemic MRSA from a University
Hospital and District Institutions, Finland

• Identification
• - NCCLS
• - Typed with
• International phage set ( Phage typing)
• pulsed field gel electrophoresis
• ( PFGE - molecular typing)
• Elimination treatment
• Topical or combined high risks gr.

Kotilainen P, et al. Emerg Infect Dis 20039
169 -75)
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Elimination of Epidemic MRSA from a University
Hospital and District Institutions, Finland

• Results
• 202 were infected/ colonized
• 15 strains - 10 outbreak strains
• - 5 community strains
• IC measures
• - Intensive education of staff on hospital
  hygiene
• - single room isolation
• - strict adherence
• - screening all patients in outbreak ward
• - closed to new admission ( epidemic)
• 20 staff members were colonized

Kotilainen P, et al. Emerg Infect Dis 20039
169 -75)
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Conclusion

• Aware of high risk patients
• Early identification
• Proper infection control measures
• Good surveillance systems
• Proper use of antibiotics

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Thank you