UNIT 1 Flashcards
anything in the environment that has the potential to cause harm (to medtech)
hazard
the possibility that something bad or unpleasant (such as an injury or loss) will happen
risk
aims to provide all employees a safe work environment. It was enacted by the US congress in 1970 and has widely been used as a basis by many countries internationally to come up with their own regulations concerning safety in the workplace.
Occupational Safety and Health Act (OSHA)
the governing body responsible for ensuring and monitoring the implementation of the standards set. 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)
include all pathogen or disease-causing microorganisms. These microorganisms are frequently present in the specimens that are processed in the clinical
laboratory.
pose any injury/harm to health; cause diseases (specimens)
Biohazards
illustrates how pathogens are transmitted. Understanding is essential for one to identify measures that will prevent infection. (in no particular order)
Chain of infection
The disease-causing microorganism
infectious agent/pathogen
Animate/ inanimate object where the infectious agent is found normally
living (that would allow to thrive and multiply/replicate/survive on to infect another host)
ex: human (infected patient like hiv), animal (dogs, bats with rabies), and inanimate - hook askaris tricoris (soil transmitted helminths)
reservoir
Routes and means utilized by the microorganism to escape from the reservoir (only applicable to live reservoirs) ex. body fluids
- hiv (blood/sperm) ascaris lumbricoides (feces/stool)
portal of exit
Method of conduction from the reservoir to the susceptible host
mode of transmission
person to person
contact transmission
Involves actual contact/ close proximity of the infected individual and the susceptible host (skin to skin)
direct transmission
subtype of direct contact transmission; “Mother-to-baby” transmission
vertical transmission
subtype of vertical direct contact transmission; Transfer of infectious agent happens BEFORE birth usually by crossing the placenta (baby is still in the womb; mothers blood passes to the baby)
ex: varicella (zoster virus/chicken pox)
(2nd infection shingles - more severe causes sterility in adults)
Prenatal/ Transplacental Transmission
subtype of vertical direct contact transmission; Transfer happens
during passage through the birth canal; during childbirth, contact with cervix/vagina
ex: herpes (simplex virus)
(type 1 - oral area, type 2 - genital area)
gonorrhea (can cause prenatal conjunctivitis)
Perinatal Transmission
subtype of direct contact transmission; Transmission from a person to another person within a group; No specificity when it comes to the involved hosts (contact)
ex: common cold, shaking hands
horizontal transmission
Includes Transmission by Fomites
indirect contact
Non-living object that may transmit an infectious disease (tissues, handkerchiefs, towels, doorknobs, bedding, etc)
Fomites
Respiratory particles of moisture containing an infectious agent
(coughing, sneezing, and talking) Usually have a diameter of >5 micrometers and capable only of traveling short distances (<1 meter)
time: sec-mins, PERSON TO PERSON IS NECESSARY
droplets/droplet transmission
Pathogen is spread through droplet nuclei (remnants after
evaporation of droplets)
- has a diameter less than 5 micrometers and are typically capable of travelling distances greater than 1 meter time: mins-hours NO NEED FOR PERSON TO PERSON CONTACT
airborne transmission
Transfer of infectious agents by an inanimate medium (soil, water, food)
common vehicle transmission
Pathogens are spread by contaminated water, usually with untreated or poorly treated sewage (cholera/vibrio cholerae and leptospirosis)
waterborne transmission
The pathogens usually develop in soil and is subsequently acquired by the susceptible host from the soil (Hookworm infection and Ascariasis) (hook askaris tricoris (soil transmitted helminths)
soil-borne transmission
Invertebrates capable of harbouring infectious agent
vector/vector-borne transmission
type of vector-borne transmission that utilizes mechanical vectors, The infectious agent WILL NOT develop while being transported by the vector (not allow progression, taxi of pathogen, pass in egg form)
ex: housefly (salmonella typhi)
Mechanical transmission
type of vector-borne transmission that utilizes biological vectors, the infectious agent WILL develop while being transported by the vector (progress egg to larvae/progression of life cycle)
ex: mosquito (P. falciparum) malaria
biological transmission
Routes through which the pathogen enter the host
(V. cholerae - gastrointestinal tract = disease; respiratory tract = no disease)
portal of entry
If not followed, the entry of the infectious agent to the susceptible
human host will result to non-development of a disease or a milder form of the disease
preferred portal of entry
if healthy it (pathogen/infectious agent) will not survive; no infection
SUSCEPTIBLE HUMAN HOST
The three components that are incorporated in this model are: (a) source, (b) transmission,
and (c) host.
CHAIN OF INFECTION: 3-PART MODEL
has four circles and is
universally adapted to warn about the existence of biological hazards.
biohazard symbol
(pathogen, reservoir, source)
Hand washing
Biohazardous waste disposal Decontamination
Specimen bagging
source
(portal of entry, mode of transmission, portal of exit)
Hand washing
Personal protective equipment
Aerosol prevention
Sterile/disposable equipment
Pest control
mode of transmission
(susceptible host)
Standard precautions
Immunization
Healthy lifestyle Exposure control plan
Postexposure prophylaxis
host
Not known to consistently cause diseases in healthy adults
(Bacillus subtilis,
Mycobacterium gordonae)
biosafety level 1 agent
Relatively common agents that are
associated with human disease Routes of transmission include
percutaneous injury, ingestion, and
mucous membrane exposure
Escherichia coli, Hepatitis B
virus, Human Immunodeficiency Virus, Influenza virus
biosafety level 2 agent
Indigenous or exotic agents that may cause serious or potentially lethal
disease through inhalation route of exposure
Bacillus anthracis, Francisella,
Brucella, Mycobacterium
tuberculosis, Mold stages of
systemic fungi
biosafety level 3 agent
Dangerous or exotic agents which post high individual risk of aerosol-transmitted laboratory infections that are frequently fatal, for which there are no vaccines or treatments
Ebola virus, Lassa virus, Viruses
that cause hemorrhagic
fevers
biosafety level 4 agent
Agents not associated with disease in healthy adult humans
No or low individual and community risk
risk group 1
Agents associated with human
disease that is rarely serious and for which preventive or therapeutic interventions are often available. Moderate individual risk; low
community risk
risk group 2
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
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
protects people from germs/pathogens
“Containment principles, technologies, and practices that are
implemented to prevent unintentional exposure to pathogens or toxins, or their accidental release
biosafety
protects (dangerous) germs/pathogens from people/terrorists
“The protection, control, and accountability for valuable biological
materials within the laboratories, in order to prevent their unauthorized
access, loss, theft , misuse, diversion, or intentional release
biosecurity
Mandates that 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
Considers all body fluids and moist body substances to be potentially infectious
Did not recommend hand washing following removal of gloves
unless visual contamination is present
body substance isolation
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
Single most effective way of controlling the spread of infectious diseases
PROPER HAND WASHING
a. Wet hands with clean, running water and apply soap.
b. Rub hands together to make a lather
According to WHO guidelines,rubbing of hands should last for AT
LEAST ______
Proper duration of hand-rubbing is approximately equal to the duration of singing _______
c. Rinse hand with clean water
d. Dry hands with single-use towel and use towel to turn off the faucet
- 20 SECONDS
- 2 HAPPY BIRTHDAY SONGS
Protective clothing, helmets and other garments designed to protect the wearer’s body from injury or infection
Common PPE worn by laboratory personnel:
Laboratory gown Scrub suits Head cover
Goggles Respirators Rubber boots and overshoes
Medical Mask Face Shield
UTILIZATION OF PERSONAL PROTECTIVE EQUIPMENT (PPE)
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 filter (Characterized by pores having a diameter of 0.3 um, Removes air-suspended materials having diameter greater than 0.3 um
o Capable of removing up to 99.97% of air-suspended materials)
HEPA filter/High Efficiency Particulate Air Filter
Pathogens are transmitted in foods that are incompletely cooked, poorly refrigerated, or prepared under unsanitary conditions
(tapeworm infection, salmonella typhi, taenia spp.)
foodborne transmission
Aka Open Front BSC
provides worker and environment protection BUT DOES NOT provide product/sample protection.
- 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
- 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
provides worker protection, product/ sample protection, and environmental protection.
Protects the worker from potentially infectious aerosols; Also capable of protecting the sample from possible contamination
Air passes through HEPA filter BEFORE flowing over the materials within
Air that reaches the materials within the working area is already
sterile, Protects the specimen from contamination
Air to be exhausted first passes through HEPA filter
Protects the worker and the environment from potentially
infectious aerosols
biosafety cabinet class 2
Types of BSC II
BSC Class IIA: __% of air is recirculated to the working area; __% of air is exhausted
BSC Class IIB1: __% of air is recirculated to the working area; __% of air is exhausted
BSC Cass IIB2: __ recirculation of air; Total exhaust of air through an
exhaust HEPA filter
- 70% 30%
- 30% 70%
- no
Completely enclosed and are equipped with glove ports; Infectious material within is handled with rubber gloves that are attached and sealed
Biosafety Cabinet Class 3
Minimal Risk; Only Biosafety Level 1 agents are encountered (not cause diseases)
Practices include the essentials of Standard precautions
Does not utilize Biological Safety Cabinets, only needs hand washing facilities
biosafety level 1
Moderate Risk; Biosafety Level 2 agents are likely to be encountered
Vaccination against common infectious agents such as Hepatitis B
Limiting access to the laboratory during working procedures
Training laboratory personnel in handling pathogenic agents
Direction by competent supervisors
biosafety cabinet level 1 and 2 common vehicle transmission except for airborne transmission
biosafety level 2
High risk; Biosafety Level 3 agents are encountered
Controlled access
Decontamination of all wastes
Decontamination of laboratory clothing before laundering
biosafety cabinet level 1 2 and 3 airborne transmission but treatment and prevention is AVAILABLE
biosafety level 3
Extreme risk; Biosafety Level 4 agents are encountered
Clothing change before entering
Shower on exit
Special protective clothing
biosafety cabinet level 3 ONLY airborne transmission but treatment and prevention is NOT AVAILABLE
biosafety level 4
establishment of biosafety and biosecurity manual in a
clinical laboratory creates a safe work environment
DOH Administrative Order No. 2007-0027, also known as the
“Revised Rules and Regulations Governing the Licensure and Regulation of Clinical
Laboratories in the Philippines”
