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 laboratory-acquired 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 BSL-4 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 GROUPCLASSIFICATION

• 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.