Download RISK ASSESSMENT

Biosafety in the Clinical
Microbiology Lab
Mohammad Rahbar (PhD)
Associated Professor
Iranian Health Reference Laboratory
Introduction
• 1951,1965, 1976 - Sulkin and Pike
• Surveys for lab-associated infections
– More than 5,000 labs
– Cumulative total of 3,921cases cited
– Most commonly reported:
•
•
•
•
Hepatitis
Brucellosis
Tuberculosis Tularemia
Typhoid
Venzuelan Equine Encephalitis
Introduction
• 1951,1965, 1976 - Sulkin and Pike
(cont.)
• Surveys for lab-associated infections
– Fewer than 20% associated with known
accidents
– Exposure to infectious aerosols plausible (but
unconfirmed) for >80% of reported cases.
Biosaty
• Definition
• The application of safety principles to a
laboratory in which biological organisms are
manipulated.
Risk analysis
• The World Health Organization (WHO)
describes risk analysis as a process
composed of three elements—
1-risk assessment,
2-risk management
3- communication.
Risk assessment
Continue..
Biological Risk Assessment
• Risk assessment is an important
responsibility for directors and principal
investigators of microbiological and
biomedical
laboratories.
Institutional
biosafety committees (IBC),animal care
and use committees, biological safety
professionals, and laboratory animal.
veterinarians share in this responsibility.
Biological Risk Assessment
• Risk assessment is a process used to
identify the hazardous characteristics of a
known infectious or potentially infectious
agent or material, the activities that can
result in a person’s exposure to an agent,
the likelihoodthat such exposure will cause
a LAI, and the probable consequences of
such an infection.
Biological Risk Assessment
• The information identified by risk
will
provide a guide for the selection of
biosafety levels. and microbiological
practices, safety equipment, and facility
that can prevent LAIs.
Biological Risk Assessment
• Laboratory
directors
and
principal
investigators should use risk assessment
to alert their staffs to the hazards of
working with infectious agents and to the
need for developing proficiency in the use
of selected safe practices and containment
equipment.
Biological Risk Assessment
• Successful control of hazards in the
laboratory also protects persons not
directly associated with the laboratory,
such as other occupants of the same
building, and the public.
Biological Risk Assessment
• Risk
assessment
requires
careful
judgment. consequences are more likely
to occur if the risks are underestimated. By
contrast, imposition of safeguards more
rigorous than actually needed may result
in additional expense and burden for the
laboratory, with little safety enhancement.
Biological Risk Assessment
• Unnecessary burden may result in
circumvention of required safeguards.
However, where there is insufficient
information to make a clear determination
of risk, it is prudent to consider the need
for additional safeguards until more data
are available.
Biological Risk Assessment
• The primary factors to consider in risk
assessment and selection of precautions
fall into two broad categories:
• Agent hazards.
• Laboratory procedure hazards.
• In addition, the capability of the laboratory
staff to control hazards must be
considered.
Biological Risk Assessment
• This capability will depend on the
training.
technical proficiency,
good habits of all members of the
laboratory,
The operational integrity of containment
equipment and facility .
RISK ASSESSMENT--THE WHAT
• Performing a risk assessment of the
workplace is the first step toward ensuring
that all workers have safe and healthy
working
environments.
Unfortunately,
everyone in the laboratory community
does not have the same understanding of
what is meant by “risk” or “risk
assessment.”
The
following
are
selected
definitions that will be used in risk
assessment
• Risk is the chance of injury, damage, or
loss.
• Chance means the probability of
something happening.
Hazard
• A Hazard is something that is dangerous-an object, a chemical, an infectious agent,
or a situation. Hazards are categorized
into three groups: Physicalhazards,
Chemical hazards, and Biological
hazards. Here are some examples of
hazards and the risks associated with
each hazard.
Risk assessment
• Risk assessment is an action or a series
of actions taken to recognize or identify
hazards and to measure the risk or that
something will happen because of that
hazard. In evaluating risk, the severity of
the consequences is also taken into
account.
factors to consider when doing a
risk assessment of a spill include
• The amount of material spilled.
• The presence and number of infectious
particles or the concentration of a
chemical agent
• the nature of the ventilation in the room.
• the personal protection equipment, such
as a respirator, being worn by those in the
room.
Evaluations of risk may be only partly quantitative;
complete assessment also
requires
• background information
• experience.
• common sense.
• ability to visualize potential outcome.
Tools useful in performing
laboratory risk assessments are-•
•
•
•
•
Reviewing laboratory records.
Injury, illness, and surveillance reports.
Equipment maintenance records.
Employee training records.
Environmental monitoring records.
Inspecting the laboratory
• Daily monitoring by employees.
• Periodic walk-through.
• Formal inspections by certifying agencies.
Reviewing published materials.
•
•
•
•
•
Equipment manuals.
Manufacturers’ bulletins and newsletters
Product inserts.
Scientific journals.
Published safety manuals and guidelines.
Observing laboratory operation (requires a knowledge of
relevant literature.
•
•
•
•
New procedures
New employees
New equipment
Work-flow.
RISK ASSESSMENT--THE WHY
• Why do risk assessments?
• Risk assessments provide us with the
information we need to keep people safe• people in the laboratory, people in the
entire facility, and people in the external
environment, i.e., the community.
Some additional benefits
•
•
•
•
•
•
•
•
Effective use of resources
Identification of training needs and supervision
Advance planning for renovations
Evaluation of procedural changes
Prevention of biohazard transmission to family members
of employees
Ensure compliance with governmental regulations
Justification for space and equipment needs
Cost effective laboratory operation
Evaluation of emergency plans.
RISK ASSESSMENT--THE WHEN
• When should risk assessments be
done?
• Risk assessments should be done at
regular intervals, at least annually, but
more
• frequently if problems are discovered.
A risk assessment should be done whenever a change
occurs in the laboratory such
as
• move or renovation
• new employee
• new infectious agent or new reagent
• new piece of equipment
Important factors in Risk
Assessment of microorganisms
• The pathogen city of the infectious or suspected
infectious agent, including disease incidence
and severity (i.e., mild morbidity versus high
mortality, acute versus chronic disease). The
more severe the potentially acquired disease,
the higher the risk. For example, staphylococcus
aureus only rarely causes a severe or life
threatening disease in a laboratory situation and
is relegated to BSL-2.
Pathogencity
• Viruses such as Ebola, Marburg, and Lassa
fever, which cause diseases with high mortality
rates and for which there are no vaccines or
treatment, are worked with at BSL-4. However,
disease severity needs to be tempered by other
factors. Work with human immunodeficiency
virus (HIV) and hepatitis B virus is also done at
BSL-2, although they can cause potentially lethal
disease. But they are not transmitted by the
aerosol route, the incidence of laboratoryacquired infection is extremely low for HIV, and
an effective vaccine is available for hepatitis B .
The route of transmission
• The route of transmission (e.g., parenteral,
airborne, or by ingestion) of newly isolated
agents may not be definitively established.
Agents that can be transmitted by the aerosol
route have caused most laboratory infections. It
is wise, when planning work with a relatively
uncharacterized agent with an uncertain mode
of transmission, to consider the potential for
aerosol transmission. The greater the aerosol
potential,
the
higher
the
risk.
Agent stability
• Agent stability is a consideration that
involves not only aerosol infectivity (e.g.,
from spore-forming bacteria), but also the
agent's ability to survive over time in the
environment.( e.g M.tuberculosis) Factors
such as desiccation, exposure to sunlight
or ultraviolet light, or exposure to chemical
disinfectants must be considered.
The infectious dose
• The infectious dose of the agent is another
factor to consider. Infectious dose can vary from
one to hundreds of thousands of units. The
complex nature of the interaction of
microorganisms and the host presents a
significant challenge even to the healthiest
immunized laboratory worker, and may pose a
serious risk to those with lesser resistance. The
laboratory worker's immune status is directly
related to his/her susceptibility to disease when
working
with
an
infectious
agent.
The concentration
• The volume of concentrated material being
handled is also important. In most
instances, the risk factors increase as the
working
volume
of
high-titered
microorganisms
increases,
since
additional handling of the materials is often
required.
The origin of the potentially
infectious material
• The origin of the potentially infectious material is
also critical in doing a risk assessment. "Origin"
may refer to geographic location (e.g., domestic
or foreign); host (e.g., infected or uninfected
human or animal); or nature of source (potential
zoonotic or associated with a disease outbreak).
From another perspective, this factor can also
consider the potential of agents to endanger
American livestock and poultry .
The availability of data from animal
studies
• in the absence of human data, may
provide useful information in a risk
assessment.
Information
about
pathogenicity, infectivity, and route of
transmission in animals may provide
valuable clues. Caution must always be
exercised,
however,
in
translating
infectivity data from one species of animal
to another species .
The established availability of an
effective prophylaxis or therapeutic
• The established availability of an effective
prophylaxis or therapeutic intervention is another
essential factor to be considered. The most
common form of prophylaxis is immunization
with an effective vaccine. Risk assessment
includes determining the availability of effective
immunizations. In some instances, immunization
may affect the biosafety level (e.g., the BSL4 Junin virus can be worked on at BSL-3 by an
immunized worker). Immunization may also be
passive (e.g., the use of serum immunoglobulin
in HBV exposures
The established availability of an
effective prophylaxis or therapeutic
• However important, immunization only
serves as an additional layer of protection
beyond engineering controls, proper
practices and procedures, and the use of
personal
protective
equipment.
Occasionally, immunization or therapeutic
intervention (antibiotic or antiviral therapy)
may be particularly important in field
conditions. The offer of immunizations is
part of risk .
Medical surveillance
• Medical surveillance ensures that the
safeguards decided upon in fact produce
the expected health outcomes. Medical
surveillance is part of risk management. It
may include serum banking, monitoring
employee health status, and participating
in post-exposure management.
RISK GROUP
CLASSIFICATION
• Risk Group 1:
No or low individual and community risk) A
microorganism that is unlikely to cause or
animal disease.
Risk Group 2
• (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
preventive measures are available and the
risk of spread of infection is limited.
Risk Group 3
• High individual risk; low community risk) A
pathogen that usually causes serious
animal disease but does not ordinarily
spread from one infected individual to
another. Effective treatment is available.
Risk Group 4
• (High individual and community risk) A
that usually causes serious human or
disease and that can be readily from one
individual to another, directly or indirectly.
Effective
treatment
and
preventive
measures are not usually available.