prevention of disease transmission ch 18 Flashcards
5 major groups of microorganisms
bacteria, viruses, algae, protozoa, fungi
Bacteria
consist of only a single cell
vary in size/shape
been found to live temp above boiling point and in cold below freezing point
normal flora
some microorganisms are not a problem and are expected to be there. EG) skin, respiratory tract, gi tract
bacteria shape (coccus)
sphere
bacteria shape (bacillus)
rod
bacteria shape (spirochete)
spiral
streptococci
form chains as they divide, responsible for strep throat, endocarditis, pneumonia, etc
staphylococci
form regular groups or clusters
staphylo = bunch of grapes/clusters
clostridium botulinum, e.coli, tubercular bacilli(tb), clostridium tetani.. are all diseases caused by
Rod (bacilli)
spirochetes
spiral-shaped bacteria have flexible cell walls and are capable of movement
caused by the bacterium mycobacterium tuberculosis.
Highly contagious disease.
spread from one person to another through tiny droplets released into the air
Tuberculosis (TB)
Symptoms of TB
fever, fatigue, night sweats, loss of weight
Gram-positive
bacteria that are stained by a dye, appears dark purple under the microscope
gram-negative
do not hold the stain, almost colorless and nearly invisible under a microscope
aerobes
bacteria that need oxygen to grow
anaerobes
bacteria that grow in the absence of o2 and are destroyed by o2
facultative anaerobes
could live either with or without o2
eg) streptococci, e.coli
some bacterias form this which is a protective layer that covers the cell wall. These protected bacteria are generally virulent
Capsules
smaller than bacteria, but can cause fatal diseases
virus
range from single-cell organisms to larger multiple-cell organisms like seaweed and kelp. contain chlorophyll
algae
consists of a large group of one-cell organisms. Found in freshwater and marine habitats and moist soil, do not cause disease but some live in hosts and do cause damage
protozoa
fungi
are plants such as mushrooms, yeats, and molds.
candida
common yeast found in the oral cavity. Also found in the GI tract and female genital tract
oral candidiasis
caused by yeast Candida Albicans and is treated with a topical antifungal preparation (wash)
short for proteinaceous infectious particle, composed entirely of proteins that lack nucleic acids (DNA OR RNA)
Responsible for a group of chronic diseases
prions
creutzfeldt- jakob disease
caused by prion disease. neurological disorder. Nervous system disease that causes dementia
reservoir
a place where microorganisms normally live and reproduce eg) humans, water, food blood&saliva
portal of exit
path by which the pathogen leaves its host eg) respiratory tract, urinary tract, cut in the skin
portal of entry
pathogens must have a portal of entry or means of entering the body to cause infection
Airborne pathogens enter
through the mouth and nose
bloodborne pathogens must access
the blood supply, this occurs through a break in the skin caused by a needle stick, cut, or human bite
susceptible host
a person who is unable to resist infection by the pathogen.
Latent infection
a persistent infection in which the symptoms come and go.
Eg) cold sores, herpes
communicable disease
caused by infection spreading from person to person or through contact with body fluids.
inherited immunity
present at birth
acquired immunity
developed through a person lifetime
airborne transmission
also known as droplet infection.
Spread through droplets of moisture containing bacteria/virus
Aerosols, spray, or spatter
generated during dental treatment and can contain blood, saliva.
Aerosols
smallest, mist-like, and can remain airborne
Created by the highspeed handpiece and ultrasonic scaler during procedures
indirect transmission
microorganisms are transmitted to an object or surface and then transferred to another person who touches that as well. Eg) dental chart
parenteral transmission
through the skin, as with cuts or punctures.
bloodborne transmission
occurs through direct or indirect contact with blood and other body fluids
food and water transmission
transmitted by contaminated food that has not been cooked or refrigerated properly and water that has been contaminated
fecal-oral transmission
if hands aren’t washed properly after bathroom, pathogens may be transmitted directly by touching another or by directly contacting a contaminated surface
disease producing microorganisms are termed
pathogenic
none disease producing microorganisms
nonpathogenic
capable of causing serious disease
virulent
organisms that can grow in the precedes or absence of oxygen are
facultative anaerobes
single celled microscopic animal without a rigid cell way
protozoan
is a hidden virus during the latency period
provirus
prion
tiny infectious agents that do not contain dna or rna
bacteria can change into highly resistant form called
spore
virus necessary for co-infection with HDV
HBV
virus that is spread by the feral-oral route
HAV
virus spread by mosquitoes
West Nile virus
the virus caused by A-type viruses
H1N1 flu virus
the bacterium that is resistant to some antibiotics
MRSA
