2. Principle of Biosafety
ďŽ Biosafety Levels 1-4 describe combinations of:
â Laboratory Practices and Techniques
â Safety Equipment including PPE (Primary Barriers)
â Laboratory Facilities (Secondary Barriers)
ďŽ Biosafety Levels 1-4 Provide
â Increasing levels of personnel and environmental protection
â Guidelines for working safely in laboratories using biological
agents
3. Principle of containment
⢠Used to describe safe methods for
managing infectious agent in the
laboratory environment where they are
being handle or maintained.
4. Elements of containment
⢠Primary containment
- Protection of personnel and the immediate laboratory
environment
- Use of laboratory practices, technique, safety equipment
⢠Secondary containment
- Protection of environment external to immediate
laboratory
5. Selection of containment measures
( the biosafety level)
⢠Knowledge of containment mechanisms( theKnowledge of containment mechanisms( the
laboratory)laboratory)
- understanding of the mechanisms of- understanding of the mechanisms of
containment and measures used to controlcontainment and measures used to control
the potential for escape, transmission andthe potential for escape, transmission and
exposureexposure
⢠Match containment to riskMatch containment to risk
⢠Source of assistanceSource of assistance
- National/ international guidelines and- National/ international guidelines and
professional biosafety personnelprofessional biosafety personnel
6. Biosafety Level 1 (BSL-1)
⢠Suitable for work involving well-characterized
agents not known to consistently cause
disease in immuno competent adult humans
⢠Minimal potential hazard to laboratory
personnel and the environment
⢠Laboratories are not necessarily separated
from the general traffic patterns in the building
e. g biological lab in secondary school or
college working with e coli
7. Biosafety Level 2 (BSL-2)
⢠Builds upon BSL-1
⢠BSL-2 is suitable for working involving agents that pose
moderate hazards to personnel and the environment
⢠Laboratory personnel have specific training in handling
pathogenic agents
⢠Personnel are supervised by scientists competent in
handling infectious agents an associated procedures
⢠Access to the laboratory is restricted when work is being
conducted
8. Biosafety Level 2 ( BSL-2)
⢠All procedures in which infectious aerosols
or splashes may be created are conducted
in biological safety cabinets (BSCs) or other
physical containment equipment
⢠Mandatory warning Sign
- Designate Biosafety Level
- Special Entry Procedures
- Immunizations
- PPE
- Contact Information
⢠E. g Hospital Lab, Universities working with Streptococci
10. Biosafety Level 3 (BSL-3)
⢠Is applicable to clinical, diagnostic, teaching, research or
production facilities where work is performed with
indigenous or exotic agents that may cause serious or
potentially lethal disease through inhalation route
exposure.
⢠Laboratory personnel must receive specific training in
handling pathogenic and potentially lethal agents
⢠Must be supervised by scientists competent in handling
infectious agents and associated procedures
11. Biosafety Level 3 ( BSL-3)
⢠Biosafety Level-2 plus all procedures involving the
manipulation of infectious materials must be
conducted within BSCs, or other physical
⢠Personnel wear additional appropriate personal
protection equipment including respiratory protection
as determined by risk assessment
⢠A BSL-3 laboratory has special engineering and
design features
- Directional air flow
12.
13. Biosafety Level 4 (BSL-4)
⢠Required for working with dangerous and exotic agents
that pose a high individual risk of life-threatening disease,
aerosol transmission, or related agent with unknown risk
of transmission
⢠Agents with a close or identical antigenic relationship to
agents requiring BSL-4 containment must be handled at
this level until sufficient data are obtained either to confirm
continued work at this level, or re-designate the level
⢠Laboratory staff must have specific and thorough training
in handling extremely hazardous
14. Biosafety Level 4 (BSL-4)
⢠Laboratory staff must understand the primary and secondary
containment functions of standard and special practices, containment
equipment and laboratory design characteristics
⢠All laboratory staff and supervisors must be competent in handling
agents and procedures requiring BSL-4 containment
⢠Access to the laboratory is controlled by the laboratory supervisors in
accordance with institutional policies
⢠Two types of laboratory providing absolute separation of the worker
from the infectious agents (suit Laboratory & cabinet laboratory)
17. WHO Classification of infective
microorganisms by risk group
ďŽ Risk Group 1 (no or low individual and community risk)
ďŽ Risk Group 2 (moderate individual risk, low community
risk)
ďŽ Risk Group 3 (high individual risk, low community risk)
ďŽ Risk Group 4 (high individual and community risk)
18. Risk Group 1
ďŽ No or low individual and community risk
- A microorganism that is unlikely to cause human
diseases or animal disease
e.g. E.coli K12
Bacillus subtilis,
Staphylococcus epidermidis
19. Risk Group 2
ďŽ Moderate individual risk, low community risk
ďŽ Pathogen causes human or animal disease but it unlikely
to be a serious hazard to laboratory workers, the
community, livestock or the environment
ďŽ May cause serious infection but effective treatments and
preventive measures are available
ďŽ Risk of spread it limited
e.g. Herpes viruses , VSV âŚâŚ
Escherichia coli
Staphylococcus aureus
20. Risk Group 3
ďŽ High individual risk, low community risk
ďŽ Pathogen usually cause serious human or
animal disease but does not ordinarily
spread to others
ďŽ Effective treatment and preventive
measures are available
E.g Mycobacterium tuberculosis,
Burkholderia pseudomallei
Rickettsia spp.
21. Risk Group 4
ďŽ High individual and community risk
ďŽ A pathogen cause serious human or
animal disease; readily transmitted from
one individual to another
ďŽ Effective treatment and preventive
measures are usually not available
ďŽ Eg: Ebola, Marburg, and Nipah viruses
22. Risk groups & biosafety levels
BSL Laboratory type Laboratory
practices
Safety equipment
1 Basic teaching,
research
Good microbiological
techniques
None
Open bench work
2 Primary health
services; diagnostic
services, research
Good microbiological
techniques,
protective clothing,
biohazard sign
Open bench PLUS
biological safety cabinet for potential
aerosols
3 Special diagnostic
services, research
As BSL 2 PLUS
special clothing,
controlled access,
directional airflow
Biological safety cabinet and/or other
primary devices for all activities
4 Dangerous
pathogen units
As BSL 3 PLUS
airlock entry, shower
exit, special waste
Class III biological safety cabinet,
positive pressure suits, double ended
autoclave (through the wall), filtered
air
23. Risk groups
HIV 2 or 3?
Burkholderia pseudomallei 2 or 3?
Mycobacterium tuberculosis 2 or 3?
Hantavirus 2 or 3?
Rabies virus 2 or 3?
SARS virus 3 or 4?
24. Factors to consider in
Classification
ďŽ Pathogenicity of the agent
ďŽ Modes of transmission and host range of
organism
ďŽ Local availability of preventive measures
ďŽ Local availability of effective treatment
25. In summary
ďŽ There is no internationally accepted list of
microorganisms classified according to risk groups
- Different microorganisms may pose different risks in different
countries.
ďŽ WHO recommends each country (region) to draw up a
national (region) classification of microorganisms by risk
group
ďŽ The choice of biosafety level and practices should be the
result of a comprehensive risk assessment
To know a little bit about biosafety principle & that are risk group of Mibrobiology
The goal of preventing injuries and diseases from occurring among students, scientists, laboratory staff and the community
The term containment describes safe methods for managing infectious materials in the laboratory environment where they are being handled or maintained. The purpose of containment is to reduce or eliminate exposure to potentially hazardous agents.
Exposure could involve not only laboratory workers but also other individuals working close by and the outside environment.Â
Element containment
Primary containment Is the protection of personnel and the immediate laboratory environment from exposure to infectious agents and also provided by both good microbiological technique and the use of appropriate safety equipment. For example, produce vaccines may provide an increased level of personal protection.
For the secondary containment Is the protection of the environment external to the laboratory from exposure to infectious materials
So the facility design, operational practices. Ventilation systems, controlled access, airlocks, and other facility design features must be part of any biosafety program.Â
Knowledge of agent characteristics
- virulence and pathogenicity
- Experimental procedures and manipulations that influence escape, transmission and exposure
Risk assessment to evaluation of hazards and the potential for laboratory-associated disease
Sources of assistance
National/international guidelines and professional biosafety personnel
Level 1 for agents that are âdefined and characterized strains of viable microorganisms not known to consistently cause disease in healthy adult humans.âB. subtilis, E. coli K12,
S. cervasiae Containment relies on âstandard microbiological practices, no specialâŚbarriers other than a sink for hand washing.â
Level 2 for the âbroad spectrum of indigenous moderate-risk agents that are present in the community and associated with disease of varying severity.â S. aureus, B. anthracis, HIV, Hep B Containment relies primarily on âgood microbiological techniqueâŚâ
provided the potential for producing splashes and aerosols is low.
Primary hazard is by accidental percutaneous or mucous membrane exposure. Careful with sharps!!!
This moderate-risk agents that pose a danger if accidentally inhaled, swallowed or exposed to the skin.
Safety measures include limited access, biohazard warning signs, sharps precautions, class I or II BSCs
The use of PPE such as gloves and eyewear as well as hand washing sinks and waste decontamination facilities such as an autoclave.Â
BSL-3 laboratories are used to study agents that work is done with indigenous or exotic agents with a potential for respiratory transmission, and which may cause serious and potentially lethal infection
Laboratory personnel must receive specific training and equipment in handling pathogenic agents.
Supervision by a competent scientist who is experienced in working with these agents.
Biosafety Level 3, more emphasis is placed on primary and secondary barriers to protect personnel in this areas
All laboratory manipulations should be performed in a BSC
Personnel wearing appropriate personal protective clothing
Secondary barriers for this level include controlled access to the laboratory and ventilation requirements to minimize the release of infectious aerosols from the laboratory Biosafety Level 3Â
Biosafety Level 4 should be under the control of national or other appropriate health authorities.
Required for working with dangerous and exotic agents that pose a high individual risk of aerosol transmitted laboratory infections and life threatening disease.
Which there is no available vaccine or therapy Agents with a close or identical antigenic relationship to Biosafety Level 4 agents also should be handled at this level When sufficient data are obtained, work with these agents may continue at this level or at a lower level
The laboratory worker's complete isolation from aerosolized infectious materials is accomplished primarily by working in a Class III BSC or in a full-body, air-supplied positive-pressure personnel suitÂ
Personnel must receive specialized training in handling extremely dangerous infectious agents, containment equipment and functions
All laboratory staff and supervisors must be competent in handling agents and procedures requiring
Access to the laboratory is controlled by the laboratory supervisors in accordance with institutional policies
Two types of laboratory providing absolute separation of the worker from the infectious agents
The World Health Organization (WHO) developed a Risk Group classification of infective microorganisms handled in laboratories that emphasizes the importance of assessing both individual and community risks.
The Risk Group classification describes four risk groups 1, 2, 3 and 4
A pathogen that can cause human or animal disease
but is unlikely to be 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.
Pathogenic, cause serious disease
Effective treatment and preventive measures usually available
Little person-to-person spread
pathogenic agent Readily transmittable direct, indirect
Effective treatment and preventive measures not usually available
influenced by existing levels of immunity in the local population and movement of the host population, presence of appropriate vectors and standards of environmental hygiene.
- prophylaxis by immunization or administration of
antisera (passive immunization)
- sanitary measures, e.g., food and water hygiene
control of animal reservoirs or arthropod vectors
Local availability of effective treatment
- passive immunization, pot-exposure vaccination
and use of antimicrobials, antivirals and
chemotherapeutic agents
- the possibility of the emergence of drug-resistant
strains
