Thomas M. Shinnick, Ph.D.

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Biosafety Recommendations for Laboratory Testing
for TB

• Thomas M. Shinnick, Ph.D.
• Associate Director for Global Laboratory
  Activities, Division of TB Elimination

Anticipating Biosecurity Challenges of the Global
Expansion of High Containment Biological
Laboratories July, 2011

• National Center for HIV/AIDS, Viral Hepatitis,
  STD TB Prevention

• Division of Tuberculosis Elimination

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Why is Biosafety Needed in the TB Laboratory?

• Risk of infection with M. tuberculosis is 3x to
  9x higher for TB lab workers than for other lab
  workers
• Infection often results from unrecognized
  production of infectious aerosols containing
  tubercle bacilli
• Infection can occur from needle sticks, through
  broken skin, etc.

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Biosafety Level (BSL)

• Conditions under which an infectious agent can
  ordinarily be safely handled.
• Conditions are a combination of
• laboratory practices and techniques
• safety equipment
• laboratory facilities
• Recommended BSLs for many of the infectious
  agents have been developed
• But different methods for the same agent may
  require different BSLs

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GLI Biosafety Guidance

• Biosafety guidance for TB lab procedures
• technical consultations, expert meetings
• GLI, WHO, CDC were the lead agencies
• Consensus recommendations for minimum biosafety
  requirements for
• direct AFB-smear microscopy
• processing specimens to concentrate bacilli for
  smear, culture, molecular tests
• manipulating cultures for smear, subculture, ID,
  DST, molecular tests

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Risk Assessments for TB Procedures

• Based on likelihood of producing infectious
  aerosols and the concentration of bacilli
• Limited risk for infectious aerosols
• direct AFB smear microscopy
• Moderate risk for infectious aerosols
• processing sputum specimens
• High risk for infectious aerosols
• processing cultures and suspensions

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Direct AFB Smear Microscopy

• Limited risk of generating infectious aerosols
• Work can be done on an open bench
• restricted access to the laboratory
• separate bench for smear preparation
• Adequately ventilated laboratory
• 612 ACH, directional airflow
• natural or mechanical ventilation
• Proper disposal of infectious material

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Processing Sputum Specimens for Smear, Culture,
Molecular Tests 1

• Moderate risk of generating infectious aerosols
  during specimen manipulation
• Laboratories must have restricted access and be
  separated from public areas
• Impermeable surfaces for easy cleaning
• Air flows into lab without re-circulation to
  non-lab areas (directional airflow)
• 612 ACH, closed windows
• Proper disposal of infectious material

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Processing Sputum Specimens for Smear, Culture,
Molecular Tests 2

• Class I or II Biosafety Cabinets used for all
  open manipulation of agents
• BSCs must be properly installed and certified at
  least annually
• BSC exhaust may be
• ducted to outside using a hard duct or thimble
  fitting (preferred)
• recirculated into the room if assured that the
  BSC is functioning properly
• Use aerosol-containment rotors

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Processing Cultures for Smear, ID, Subculture,
DST, Molecular Tests 1

• High risk of generating infectious aerosols
  during manipulation of liquid suspensions
• Work done in a containment lab which has
  restricted access and a double door entry
• Impermeable surfaces for easy cleaning
• sealing room for fumigation is not required
• Air flows into lab without re-circulation to
  non-lab areas (directional airflow)
• 612 ACH, mechanical ventilation, sealed windows
• Autoclave available on site

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Processing Cultures for Smear, ID, Subculture,
DST, Molecular Tests 2

• Class I or II Biosafety Cabinet used for all open
  manipulation of agents
• BSCs must be properly installed and certified at
  least annually
• BSC exhaust may be
• ducted to outside using a hard duct or thimble
  fitting (preferred)
• recirculated into the room if assured that the
  BSC is functioning properly
• Use aerosol-containment rotors

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TB Laboratory Biosafety Gaps

• What are minimum facility requirements?
• U.S./European-style BSL3?
• containment room, airflow, BSC?
• What are suitable laboratory layouts?
• What are minimum safety requirements
• for technicians who are HIV?
• for areas with high rates of MDR/XDR TB?
• When should respirators be required?
• Are Class I BSCs adequate?
• How to ensure functioning BSCs?

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BSL3 Secondary Containment

• BSL2 secondary containment plus
• Directional inward airflow without re-circulation
  to non-lab areas 6-12 ACH
• Controlled access separate area
• Double door entry (airlock)
• Enclosures for aerosol-generating equipment
• Walls, floors and ceilings are water resistant
  for easy cleaning
• Room penetrations sealed

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Interim Guidance for XDR TB

• Clinical specimens from known or highly suspected
  XDR TB patients
• BSL2 with full BSL3 practices are highly
  recommended
• Manipulation of cultures of XDR TB strains
• BSL3 practices, containment equipment, and
  facilities are required. BSL3 practices must
  include the use of respiratory protection and the
  implementation of specific procedures and use of
  specialized equipment to prevent and contain
  aerosols.

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Guidance for Samples from Known or Highly
Suspected XDR TB Patients

• Manipulation of clinical specimens
• Moderate risk facilities with high risk
  practices PPE are highly recommended
• Manipulation of cultures
• High risk practices, containment equipment, and
  facilities are required. Practices must include
  the use of respiratory protection and the
  implementation of specific procedures and use of
  specialized equipment to prevent and contain
  aerosols.

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Acknowledgements

• Véronique Vincent
• CN Paramasivan
• Chris Gilpin
• Daniela Cirillo
• Jean Joly
• Jenny Allen
• John Ridderhof
• Jon Crane
• Knut Feldmann
• Moses Joloba
• Paul Jensen

• Peter van't Erve
• Philippe Dubois
• Sang Jae Kim
• Shanna Nesby
• Thomas Shinnick
• Andrew Ramsay
• Karin Weyer
• May Chu
• Nicoletta Previsani
• Sebastien Cognat

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• Thank You

• National Center for HIV/AIDS, Viral Hepatitis,
  STD, and TB Prevention

• Division of TB Elimination