Module 6 Unit 1 - PRINCIPLES OF BIOHAZARD AND BIOSAFETY Flashcards
“Revised Rules and Regulations Governing the Licensure and Regulation of Clinical
Laboratories in the Philippines”, the establishment of biosafety and biosecurity manual in a
clinical laboratory creates a safe work environment.
DOH Administrative Order No. 2007-0027
refer to anything in the environment that has the potential to cause harm
Hazards
the possibility that something bad or unpleasant (such as an injury or loss) will
happen.
risk
aims to provide all employees (clinical
laboratory personnel included) a safe work environment.
Occupational Safety and Health Act (OSHA)
When was the OSHA enacted, and by who?
enacted by the US
congress in 1970
is the governing body responsible for ensuring and monitoring the implementation of the standards set by the above-mentioned act. It is authorized to conduct on-site inspections to determine whether an employer is complying with the mandatory standards.
Occupational Safety and Health Administration (also OSHA)
The (blank) exposes its workers to a variety of (blank), some of which are not seen in other (blank).
The clinical laboratory exposes its workers to a variety of hazards, some of which are not seen in other workplaces.
include all pathogen or disease-causing microorganisms. These microorganisms are frequently present in the specimens that are processed in the clinical laboratory.
Biohazards
illustrates how pathogens are transmitted. Understanding it is essential for one to identify measures that will prevent infection.
chain of infection
o The disease-causing microorganism
INFECTIOUS AGENT / PATHOGEN
Animate/ inanimate object where the infectious agent is found normally
living
RESERVOIR
Examples of reservoirs
human reservoir (infected patient), animal reservoir, and inanimate reservoir
Routes and means utilized by the microorganism to escape from the reservoir
PORTAL OF EXIT
Method of conduction from the reservoir to the susceptible host
MODE OF TRANSMISSION
Modes of Transmission
Contact, Airborne, Common Vehicle, and Vector-borne
Types of Contact Transmission
Direct, Indirect, Droplet
Involves actual contact/ close proximity of the infected individual and the susceptible host
Direct contact
Subtypes of Direct Contact
Vertical & Horizontal
“Mother-to-baby” transmission
Vertical
Classifications of Vertical Transmission
Prenatal/ Transplacental Transmission & Perinatal Transmission
Transfer of infectious agent happens
BEFORE birth usually by crossing the
placenta
Prenatal/ Transplacental Transmission
Transfer happens during passage through the birth canal
Perinatal Transmission
Transmission from a person to another person within a group; No specificity when it comes to the involved hosts
Horizontal Transmission
Includes Transmission by Fomites
Indirect contact
Non-living object that may transmit an infectious disease (Examples include tissues, handkerchiefs, towels, doorknobs, bedding, etc. )
Fomites
Respiratory particles of moisture containing an infectious agent
Droplets
How are droplets expelled into the air?
Coughing, sneezing, and even by talking
Diameter, distance, and time of droplets
> 5 micrometers, <1 meter (short distances), seconds to minutes (fast)
Pathogen is spread through droplet nuclei (remnants after evaporation of droplets)
Airborne Transmission
Diameter, distance, and time of droplets
<5 micrometers, >1 meter (long distances), minutes to hours
Transfer of infectious agents by an inanimate medium
Common Vehicle Transmission
Types of inanimate medium
Soil, water, and food
Types of Common Vehicle Transmission
Waterborne, Soil-borne, and Foodborne
Pathogens are spread by contaminated water, usually with untreated or poorly treated sewage
Waterborne
Diseases transmitted via Waterborne Transmission
cholera and leptospirosis
pathogens usually develop in soil and is subsequently acquired by the susceptible host from the soil
Soil-borne transmission
Soil Transmitted Helminths (STH)
Hookworm, Ascaris, Trichuris
Diseases transmitted via Soil-borne
Hookworm infection and Ascariasis
Pathogens are transmitted in foods that are incompletely cooked, poorly refrigerated, or prepared under unsanitary conditions
Foodborne
Diseases transmitted via foodborne
tapeworm infection
Invertebrates capable of harbouring infectious agent
Vector
Utilizes mechanical vectors
The infectious agent WILL NOT develop while being transported by the vector
Mechanical transmission
Utilizes biological vectors
The infectious agent WILL develop while being transported by the vector
Biological transmission
Routes through which the pathogen enter the host
PORTAL OF ENTRY
If not followed, no development or milder version of disease will form
Preferred portal of entry
If Vibrio cholerae will enter via the GI tract, will cholera develop?
Yes
If Vibrio cholerae will enter through the respiratory tract, will cholera develop?
No
Unhealthy/ sick individual or patient
SUSCEPTIBLE HUMAN HOST
Components found in the 3-Part Model
Source, Transmission, Host
Symbol used by the 3-part model
biohazard symbol
Also included in the 3-part model in order to break the chain in each component
Preventive measures
Not known to consistently cause
diseases in healthy adults
Biosafety Level 1
Agent
Bacillus subtilis,
Mycobacterium gordonae
Biosafety Level 1
Agent
common agents associated with human disease
percutaneous injury, ingestion, and
mucous membrane exposure
Biosafety Level 2
Agent
Escherichia coli, Hepatitis B
virus, Human
Immunodeficiency Virus,
Influenza virus
Biosafety Level 2
Agent
indigenous/ exotic agents
may cause serious/ lethal disease via inhalation or exposure
Biosafety Level 3
Agent
Bacillus anthracis, Francisella,
Brucella, Mycobacterium
tuberculosis, Mold stages of
systemic fungi
Biosafety Level 3
Agent
dangerous or exotic agents which pose HIGH individual risk aerosol-transmitted laboratory infections that are frequently fatal
NO vaccines or treatments
Biosafety Level 4
Agent
Ebola virus, Lassa virus, Viruses
that cause hemorrhagic
fevers
Biosafety Level 4
Agent
The risk group classification is utilized by both?
National Institutes of Health (NIH) and the
World Health Organization (WHO)
NIH Guidelines
Agents not associated with
disease in healthy adult humans
Risk Group 1
NIH Guidelines
Agents associated with human
disease that is rarely serious and
for which preventive or
therapeutic interventions are
often available.
Risk Group 2
NIH Guidelines
Agents associated with serious or
lethal human disease for which
preventive or therapeutic
interventions may be available
(high individual risk but low
community risk).
Risk Group 3
NIH Guidelines
Agents likely to cause serious or
lethal human disease for which
preventive or therapeutic
interventions are not usually
available (high individual risk and
high community risk).
Risk Group 4
WHO Laboratory Biosafety Manual
No or low individual and community
risk
A microorganism unlikely to cause
human or animal disease.
Risk Group 1
WHO Laboratory Biosafety Manual
Moderate individual risk; low
community risk
pathogen that can cause human
or animal disease but is unlikely to be
a serious hazard. 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 2
WHO Laboratory Biosafety Manual
High individual risk; low community
risk
pathogen that usually causes
serious human or animal disease but
does not ordinarily spread from one
infected individual to another.
Effective treatment and preventive
measures are available
Risk Group 3
WHO Laboratory Biosafety Manual
High individual and community risk
pathogen that usually causes
serious human or animal disease and
can be readily transmitted from one
individual to another, directly or
indirectly. Effective treatment and
preventive measures are NOT usually
available
Risk Group 4
Guidelines & regulations are set by the (blank) to prevent exposure to biohazards.
Centers for Disease Control and Prevention (CDC)
personnel should treat all blood and blood-contaminated samples as potentially infectious
did not treat other bodily fluids that are not visibly contaminated with blood as potentially infectious
Universal Precautions (UP)
all body fluids and moist body substances to be potentially infectious
Main flaw: Did not recommend hand washing following removal of gloves unless visual contamination is present
Body Substance Isolation (BSI)
Combined major features of universal precautions and body substance isolation
Most commonly implemented by clinical laboratories
Essentials include proper hand washing, utilization of personal protective equipment (PPE), and preventing exposure to potentially infectious aerosols/ droplets
Standard Precautions (SP)
ESSENTIALS OF STANDARD PRECAUTIONS
PROPER HAND WASHING, UTILIZATION OF PERSONAL PROTECTIVE EQUIPMENT (PPE), and BIOSAFETY CABINETS (BSC)
Single most effective way of controlling the spread of infectious diseases
PROPER HAND WASHING
Steps in Proper Hand Hygiene in Health Care Setting (based on WHO guidelines)
a. Wet hands with clean, running water and apply soap.
b. Rub hands together to make a lather
c. Rinse hand with clean water
d. Dry hands with single-use towel and use towel to turn off the faucet
Duration of rubbing hands
20 seconds or 2 happy birthday songs
Protective clothing, helmets and other garments designed to protect the
wearer’s body from injury or infection
UTILIZATION OF PERSONAL PROTECTIVE EQUIPMENT (PPE)
Common PPE worn by laboratory personnel
Laboratory gown, Scrub suits, Head cover, Goggles, Respirators, Rubber boots and overshoes, Medical Mask, and Face Shield
*Steps to put on PPE
- Always put on PPE when handling viral cases
- Dressing and undressing should always be supervised by another member of the team
- Gather all necessary equipment beforehand. Put on scrub suit in changing room.
- Put on rubber boots or closed, puncture and fluid resistant shoes and put on overshoes.
- Place impermeable gown over scrubs.
6a. Put on face mask
6b. Put on goggles. - If available, wear head cover.
- Perform hand hygiene.
- Put on gloves over cuff.
- If impermeable gown is not available, place waterproof apron over gown.
Device that encloses a workplace in such a way that protects the workers from
exposure to aerosols that may potentially contain infectious disease agents
BIOSAFETY CABINETS (BSC)
Air that may contain infectious agent is sterilized by passing through the?
HEPA filter
Meaning of HEPA Filter
High Efficiency Particulate Air Filter
pore diameter of HEPA filter
diameter of 0.3 micrometers
Removes air-suspended materials having diameter greater than 0.3 um and is capable of removing up to 99.97% of air-suspended materials
HEPA filter
Open Front BSC
Biosafety Cabinet Class I
Allow room (unsterilized) air to pass into the cabinet and around the
working area and the materials within
Does not protect the sample/ product from possible
contamination
Biosafety Cabinet Class I
Before being exhausted from the cabinet: Air passes through HEPA
filter, sterilizing the air to be exhausted
Protects the worker and the environment from potentially
infectious aerosols
Biosafety Cabinet Class I
BSC I provides worker and environment (blank) BUT (blank) provide product/
sample protection.
BSC I provides worker and environment protection BUT DOES NOT provide product/
sample protection.
Protects the worker from potentially infectious aerosols; Also capable of
protecting the sample from possible contamination
Biosafety Cabinet Class II
Air passes through HEPA filter BEFORE flowing over the materials within
Biosafety Cabinet Class II
Air to be exhausted first passes through HEPA filter
Biosafety Cabinet Class II
70% of air is recirculated to the working area; 30% of air is exhausted
BSC Class IIA
30% of air is recirculated to the working area; 70% of air is exhausted
BSC Class IIB1
No recirculation of air; Total exhaust of air through an exhaust HEPA filter
BSC Cass IIB2
AIR EITHER PASSES THROUGH THE (blank) TO BE (blank) TO THE WORKING AREA OR IT WILL PASS THROUGH THE (blank) TO BE (blank) OF THE CABINET
AIR EITHER PASSES THROUGH THE SUPPLY FILTER TO BE RECIRCULATED TO THE WORKING AREA OR IT WILL PASS THROUGH THE EXHAUST HEPA FILTER TO BE EXHAUSTED OUT OF THE CABINET
BSC class II does not provide worker protection, product/ sample protection, and
environmental protection. True or False?
False. BSC class II provides worker protection, product/ sample protection, and
environmental protection.
Completely enclosed and are equipped with glove ports; Infectious material
within is handled with rubber gloves that are attached and sealed
Biosafety Cabinet Class III
Minimal Risk; Only Biosafety Level 1 agents are encountered
Practices include the essentials of Standard Precautions
Does not utilize Biological Safety Cabinets, only needs hand washing facilities
Biosafety Level I (BSL-1)
Biosafety Level II (BSL-2)
Moderate Risk; Biosafety Level 2 agents are likely to be encountered by the
workers
Includes additional practices such as performing aerosol-generating procedures in BSC Class I or BSC Class II
Biosafety Level II (BSL-2)
High risk; Biosafety Level 3 agents are encountered by the workers
In addition to BSL 2 practices, BSL-3 also includes additional practices such as Performing aerosol-generating procedures in BSC Class I, Class II, or
Class III
Biosafety Level III (BSL-3)
Extreme risk; Biosafety Level 4 agents are encountered in the workplace
In addition to BSL 3 practices, also includes:
Clothing change before entering
Shower on exit
Special protective clothing
Requiring performance of procedures inside BSC Class III
Biosafety Level IV (BSL-4)
