Disease Prevention Flashcards
Pathogen
Microorganisms that produce disease
Major groups of microorganisms
Bacteria Viruses Algae Protozoa Fungi
Bacteria
Consists of only single cell
Live in temperatures above boiling point and and in cold that would freeze your blood
Normal flora
Harmless bacteria found in the skin, respiratory tract, and gastro-intestinal tract.
They are beneficial and protect the human host by helping with metabolism and preventing entrance of harmful bacteria.
How does infection occur with bacteria?
When bacteria occurring naturally in one part of the body invades another part of the body.
When this occurs, the normal flora are infection causing.
Bacteria shapes
Coccus - sphere
Bacillus- rod
Spirochete- spiral
Spherical - cocci
Streptococci - responsible for strep throat and pneumonia . . . They form into a chain
Staphylococci - meningitis, arthritis, boils/pimples
Rod - bacilli
E. Coli
TB
Salmonella
Spirochetes
Have flexible cell walls and are capable of movement.
Syphilis
Lyme disease
Gram positive
Used in testing, bacteria that are stained by dye and appear dark purple under a microscope
Gram negative
When testing bacteria, bacteria that do not hold the stain and are almost colorless and nearly invisible under a microscope
Aerobes
Bacteria that needs oxygen to grow
Anaerobes
Bacteria that grow in the absence of oxygen and are destroyed by oxygen
Facultative anaerobes
Could live either with the presence or absence of oxygen
Capsules
Protective layer covering cell wall of bacteria
Generally make the bacteria virulent (Apache of causing serious disease)
The capsules increase their ability to resist the bodies defense mechanisms, making them hard to treat with antibiotics
Spores
Some bacteria change into highly resistant spores during harsh conditions
Bacteria remain alive, but are inactive
Can not reproduce or cause disease
When conditions are favorable again, the bacteria become active and capable of causing disease
Spores are the most resistant form of life known
Virus
Smaller than bacteria
Can cause fatal diseases
Invade host cell, replicate itself, then destroys the host cell so the viruses are released into the body
Not capable of growth and multiplication without using cell DNA for host
Latency
Some viruses establish a dormant state in host cell
Can be reactivated in the future.
Algae
Range from single cell organisms to larger cell organisms.
Most algae do not produce human disease
Protozoa
Large group of one cell organisms.
Found in fresh water and marine habitats
Small numbers are responsible for intestinal infections
Fungi
Are plants
Candida - common yeast found in oral cavity
Candidiasis
Thrush
Caused by yeast like fungus in an HIV infected individual.
Prions
Proteinaceous infectious particle
Made of proteins that lack DNA or RNA
Responsible for “mad cow disease” (holes in the brain)
And creuzfeldt-Jakob disease (neurological disorder)
Chain of infection
- Virulence
- # of microorganisms
- Susceptible host
- Portal of entry
Virulence
The strength of an organism in its ability to produce disease.
The body cannot change the virulence of microorganisms, so we must rely on our body’s defense
of microorganisms
Pathogenic microorganisms must be high in order to cause disease
Susceptible host
A person who is unable to resist infection by the pathogen.
Individual in poor health, extreme stress or weakened immune system
Portal of entry
Pathogens must have a means of entering the body to cause infection
Chain of infection
For an infectious disease to occur, each link in the chain must be connected.
Even if one link of the chain is missing, it interrupts the process, and no infection will occur.
Acute infection
Symptoms are often quite severe and usually appear soon after the initial infection occurs.
Short duration.
Eg. Cold virus
Chronic infection
The microorganism is present for a long period; some may persist for life.
Person my be asymptomatic.
Eg. HIV
Latent infection
A persistent infection in which the symptoms come and go.
Eg. Cold sores (oral herpes)
Opportunistic infections
Occur in individuals whose resistance is decreased or compromised.
Methods of disease transmission
- direct transmission
- indirect transmission
- parenteral transmission
- blood-borne transmission
- food and water transmission
- fecal-oral transmission
Direct transmission
Person to person contact.
Droplets spread through sneezing and coughing.
Airborne transmission
AKA droplet transmission
Spread through droplets of moisture containing bacteria or viruses
Are carried long distances through the air
Indirect transmission
Microorganisms are transmitted to an object or surface, and then are transferred to another person who touches those objects or surfaces.
Parenteral transmission
Transmission of blood-borne pathogens
Can occur through needle stick injuries.
Blood-borne transmission
Pathogens are carried in the blood and bodily fluids of infected individuals.
Transmission occurs through direct or indirect contacts of these fluids.
Saliva is usually contaminated with blood.
Eg. HIV, Hepatitis B, C and D
Food and water transmission
Many diseases are transmitted by contaminated food and water that has been contaminated with human or animal fecal material
Fecal-oral transmission
Many pathogens are present in fecal matter.
Transmitted directly by touching another person or by directly contacting a contaminated surface or food.
The immune system
Is responsible for providing resistance to communicable diseases.
Communicable diseases
Caused by infection spreading from person to person or through contact with bodily fluids.
Immunity
Allows the body to resist disease and prevent foreign bodies from causing infection.
Inherited immunity
Present at birth
Acquired immunity
Developed through a person’s lifetime ( can occur naturally or artificially through vaccinations )
Why is infection control important in dentistry?
On a daily basis, DHCP’s and pts are exposed to a wide variety of disease causing organisms, AKA pathogens
Blood-borne pathogens standard
Most important infection control law in dentistry.
Guidelines designed to protect employees against occupational exposure to blood-borne pathogens.
Ex. Hep B, Hep C, HIV
Universal precautions
(Standard precautions)
Guidelines: treating all human blood and bodily fluids as potentially infectious.
All patients should be treated as if infected
Standard precautions
Since saliva has always been considered potentially infectious material in dental infection control, there is no difference between standard and universal precautions.
Routine practices
The concept that all pts are potentially infected, even when asymptomatic, the same safe standards of practice applies.
In addition, instruments in direct contact w/ these fluids & tissues are potentially contaminated w/ infectious agents.
4 principles of SAFE practice
- Risk assessment
- Hand hygiene
- Personal protective equipment
- Safe handling & disposal of sharps & contaminated waste
Risk assessment
- health status of pt
- cooperatives of pt
- physical environment / working area
- immune status of DHCP
Hand hygiene
Should be performed by washing with plain or antimicrobial soap and running water, or by using a 70-90% alcohol based hand rub UNLESS hands are visibly soiled in which only soap and water should be used.
Wash hands before you put on gloves and immediately after you remove gloves.
Always use liquid soap
Using soap and water for routine care
Wet hands with warm, not hot, water
Apply adequate amount of soap.
Rub vigorously for min. Of 10 seconds, covering all surfaces of hands.
Rinse well with running water.
Dry thoroughly with a disposable paper towel.
70-90% alcohol-based rubs
Do not require the use of water
More effective at reducing microbial flora then plain soap.
Are not indicated if your hands are visibly soiled or contaminated
Hand care recommendations
Keep skin healthy!
Do not use Vaseline-based hand locations, as they affect glove quality.
Skin will become dry due to washing- select a non-cosmetic moisturizer
Special consideration for hand hygiene
No rings, fingernail polish, or artificial nails.
These can harbor pathogens and can puncture through gloves.
PPE’s
Wear PPE’s when performing tasks that could produce splash, spatter, aerosol, or other contact with bodily fluids.
Wear PPE’s when you perform other clinical activities that require handling items contaminated with patient secretions.
Protective clothing
Purpose is to protect the skin & under clothing from exposure to saliva, blood, aerosol, and other contaminated materials.
The decision as to the type of protective clothing you should wear is based on the degree of anticipated exposure to infectious material.
