Biosafety in the TB Laboratory
Presented by
Peggy Coulter
with
(Patient Safety Monitoring in International Laboratories)
Prepared for the ACTG Conference
24 June 2009
Purpose of Training
GCLP Standards:
DAIDS supported clinical trials and studies
involving human subjects must ensure
compliance with federal regulations including
procedures to protect the safety of all
participants.
Safety of laboratory employees must be a top
priority for all lab facilities.
Abbreviations
• BMBL- Biosafety in Microbiological and
Biomedical Laboratories (CDC)
• LBM- Laboratory Biosafety Manual (WHO)
• BSC- Biosafety Cabinet
• LAI- Laboratory Associated Infection
• TB- for Mycobacteriology testing
Objectives: At the end of this training you
will be able to:
• Locate resources for biosafety guidelines;
• Describe the elements of biosafety;
• Identify standard and special practices in
biosafety;
• Select and use appropriate biosafety control
measures;
• Conduct an internal risk assessment and self
inspection of the laboratory.
Training Topics
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Principles of Biosafety
Standard Microbiological Practices
Special Practices
Personal Protective Equipment
Containment Equipment
Laboratory Facilities
Safety Practices
Risk Assessment and Self Inspection
Resources for Principles of
Biosafety
• Biosafety in Microbiological and Biomedical
Laboratories (BMBL) from CDC at
http://www.cdc.gov/OD/ohs/biosfty/bmbl5/B
MBL_5th_Edition.pdf
• Laboratory Biosafety Manual from W.H.O. at
http://www.who.int/csr/resources/publication
s/biosafety/Biosafety7.pdf
Introduction to Biosafety
All laboratory facilities must follow
“Standard or Basic Precautions”.
Biosafety guidelines evolved from the microbiological
and biomedical community to reduce laboratory
associated infections (LIA’s) and to protect the public
health and environment.
Principles of Biosafety
Two basic elements:
• Containment
• Risk Assessment
Routes of transmission for LAI’s
• Direct skin, eye, or mucosal membrane;
• Parenteral inoculation by a contaminated
sharp or needle;
• Ingestion of liquid suspension;
• Inhalation of infective aerosols.
Risk Assessment
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Pathogenicity of the microorganism
Prevalence of tuberculosis and rate of MDR
Types of testing performed or referred
Volume of tests
Personnel expertise and attitude
Facilities and equipment
WHO
Risk
Group
Risk
Microorganism
1
No or low individual
and community
risk.
A microorganism that is unlikely to cause human or animal
disease.
Moderate individual
risk, low community
risk.
A pathogen that can cause human or animal disease but is
unlikely to be a serious hazard to laboratory workers, the
community, livestock or the environment. Laboratory
exposures may cause serious infection but effective
treatment and preventative measures are available and the
risk of spread of infection is limited.
High individual risk,
low community risk.
A pathogen that usually causes serious human or animal
disease but does not ordinarily spread from one infected
individual to another. Effective treatment and preventative
measures are available.
High individual and
community risk.
A pathogen that usually causes serious human or animal
disease and that can be readily transmitted from one
individual to another, directly or indirectly. Effective
treatment and preventative measures are not usually
available.
2
3
4
Levels of Biosafety, and Testing
Levels
Testing
Level
One
Two
Three
Biosafety
Level
(BSL)
Activity
2
•Collect clinical specimens
•Transport specimens to a higher level testing laboratory
•May prepare and examine smears of killed tubercle bacilli
3
•Level One activities
•Process specimens for microscopy and culture
•Identify M. tuberculosis
•Perform DST on M. tuberculosis
3
•Level One and Two activities
•Identify all Mycobacterium species from clinical specimens
•Perform DST against all mycobacteria
•Conduct research and provide training to other laboratories
Basic Microbiology Practices
• Policies and access
• Safety practices
• Decontamination and Waste
• Training
Specimens
Photo of washroom
Handling of Specimens
• Collection
• Transportation
• Receipt of incoming
specimens
• Opening packages
Special Practices
enhance worker safety, provide
environmental protection and
address the risk of handling agents
requiring increasing levels of
containment.
Reminder: BSL-3 practices should be used whenever
M.tuberculosis is handled even if the physical
facilities are a BSL-2.
All persons entering the laboratory must
be advised of the potential hazards and
meet specific entry/exit requirements.
Animals and plants not associated with the
work being performed must not be
permitted in the laboratory.
Laboratory personnel must be
provided medical surveillance and
offered appropriate immunizations
for agents handled or potentially
present in the laboratory.
A laboratory-specific biosafety manual
must be prepared, adopted as policy
and made available and accessible to
the laboratory staff.
This is a written plan that
defines safe lab practices, spill and emergency
procedures
The laboratory supervisor must ensure
that the laboratory personnel
demonstrate proficiency in standard
and special microbiological practices
before working in the
mycobacteriology lab.
Personal Protective Equipment (PPE)
• Gowns, lab coats
• Gloves
• Respirators, masks, goggles,
glasses
• Shoe cover, boots
Lab coats vs. Gowns
Gloves
Approved Type
Correct Size
Donning
Proper Use
Removal
Shoes and Covers
Open-toed footwear is not
appropriate in the laboratory.
Respirator program
implemented by the laboratory's safety
officer or person designated to perform
this task and should include written
procedures concerning how to:
a)select the appropriate respirator,
b)conduct fit-testing, and
c)train personnel on the use, fit checking,
and storage of the respirator.
Correct Type and Fit
of Respirators
Dust
Dust and Paint Fumes
N-95
Surgical Mask
PAPR
Safety Equipment
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Needle locking syringes
Centrifuge safety carriers
Microburners
Biosafety Cabinets (BSC)
Centrifuge Safety
Biosafety Cabinets (BSC)
All procedures involving the manipulation
of infectious materials must be
conducted within a BSC, or other physical
containment devices. No work with open
vessels is conducted on the bench. When
a procedure cannot be performed within
a BSC, a combination of personal
protective devices, such as centrifuge
safety cup with sealed rotor, must be
used.
Use of BSC
A BSC is the most important piece of
containment equipment but only
• if properly installed,
• appropriate air velocity is maintained during
use,
• proper procedures are used.
Use of biological safety cabinets
Facilities
–Ventilation
–Temperature control
–Sinks, eyewash, trashcans
–Furniture and decontamination
Plan of a culture laboratory
Handling of contaminated
laboratory supplies
• Glassware
• Sputum containers
• Applicator sticks, paper, pipettes
• Positive and negative slides
Waste Handling
Potentially infectious materials must
be placed in a durable, leak proof
container during collection, handling,
processing, storage, or transport
within a facility.
No infected material should leave the laboratory
except when it is properly packed for
transport to another laboratory.
Cleaning laboratory materials
Disinfection and Sterilization
A basic knowledge of disinfection and
sterilization is crucial for biosafety in
the laboratory.
Laboratory equipment should be routinely
decontaminated, as well as, after spills,
splashes, or other potential contamination.
Autoclaves
Boiling and burning
Safety Practices
• Pipetting
• Microscopy
• Handwashing
Handwashing
Training
Initial on hire
Annual updates
Staff should be observed in their
biosafety practices
Laboratory safety does not just happen.
The best defense against a laboratory accident is
a well-thought-out plan to neutralize its
effects as quickly and effectively as possible.
• recognize that accidents can and will occur
• formulate a plan of action
• discuss ways to minimize and prevent
accidents
Spill Procedures
Laboratory accidents in the TB
laboratory result in possible
formation of aerosols.
Spills involving infectious materials must
be contained, decontaminated, and
cleaned up by staff properly trained
and equipped to work with infectious
material.
Emergency Procedures
• Puncture wounds, cuts and abrasions
• Ingestion of potentially infectious material
• Potentially infectious aerosol release (outside a
biological safety cabinet)
• Broken containers and spilled infectious substances
• Breakage of tubes containing potentially infectious
material in centrifuges not having sealable buckets
• Breakage of tubes inside sealable buckets (safety
cups)
Incidents that may result in exposure to
infectious materials must be immediately
evaluated and treated according to
procedures described in the laboratory
biosafety manual. All such incidents must be
reported to the laboratory supervisor.
Medical evaluation, surveillance, and
treatment should be provided and
appropriate records maintained.
Support Staff
The safe and optimum operation of a
laboratory is dependent to a great extent
on the support staff,
it is essential that such personnel are given
appropriate safety training.
THE MYCOBACTERIOLOGY LABORATORY
IN NEED OF IMPROVEMENT
Physical facilities
BSL-2 vs BSL-3
Laboratory Inspection
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Engineering controls
Administrative controls
Personal protective equipment
General Laboratory Safety
Risk Assessment
Will evaluate all procedures for risks related to
aerosol generation and injury from
contaminated sharp objects (e.g., needle
sticks) and develop a strategy for safe, stepby-step manipulation of both specimens and
cultures.
Why an assessment?
Who should perform it?
When should it be done?
What tools are used?
How should it be done?
Potential Hazards:
The following slides show some improper
biosafety practices or containment safeguards
found in some TB laboratories.
Summary
Although the incidence of tuberculosis is higher
in laboratory workers than for the general
population, the risk of becoming infected with
M. tuberculosis in the laboratory can be
minimized through the use of the engineering
controls, administrative procedures, and
specific work-place practices that are
presented in these guidelines.
Questions?
Resources
• www.psmile.org
• www.asm.org
• www.clsi.org
• www.cdc.gov
• www.who.int./csr/resources/publi
cations/biosafety/en/Biosafety7.pdf