Colonization
-presence and growth of microorganisms within a host > may have no
signs/symptoms
Infection
-germs are in or on the body and make you sick, which results in signs and
symptoms such as fever, pus from a wound, a high white blood cell count, or
pneumonia
Communicable disease
-is the infectious process transmitted from one person to another
hand washing
-most important technique to use in preventing and controlling transmission of
infection
Pt in all settings are at risk:
-lower resistance
-increased exposure
-resistatce to antibiotics
-invasive procedures
Healthcare workers are at risk:
-contact with pt blood and fluids
-contact with contaminated equipment and surfaces
Nature of Infection
colonization vs. infection
-disease or infection only result if the pathogens multiply and alter normal tissue
function.
Chain of Infection
COI
-Infectious agent or pathogen
,-Reservoir or source for pathogen growth
-Portal of exit
-Mode of transmission
-Portal of entry
-Susceptible host
Infectious agent
-bacteria, virus, fungi, protozoa
-resident or transcient
The potential for causing disease depends on:
-# of organisms
-virulence
-ability to enter and survive in host
-susceptibility of the host
reservoir
-place within which microorganisms can survive, multiply, and await transfer to a
susceptible host.
-HAI's
Common reservoirs for HAIs:
Healthcare workers
Patients
Equipment (eg. stethoscope)
Environment
to thrive, organisms require..
appropriate food, oxygen, water, temp, pH, light
Port of Exit
-after microorganisms find a site to grow and multiply, then must find a port of
exit if they are to enter another host and cause disease
Mode of transmission
-method of transfer by which the organism moves or is carried from one place to
another.
-unwashed hands
The major route of transmission for pathogens identified in the health care setting is
the unwashed hands of the health care worker.
,Hot spots for microorganism growth
Stethoscopes, hands, bedside commode, sinks, blood pressure cuff, IV poles, etc
Port of entry
-organisms enter the body through the same routes they use for exiting
Susceptible Host Risk factors
Nutritional status
Immunosuppression
Presence of chronic disease
Age
defenses against infection
Normal flora
-maintain sensitive balance with other microbes to prevent infection.
-releases antibacterial substances and inhibiting multiplication of pathogenic
microbes
Body system defenses
-organs have defense mechs specific to structure and function
inflammation
defensive protective reaction that delivers fluid, products, and nutrients to an area
of injury
Signs of localized inflammation -
redness, heat, swelling
Signs of systemic inflammation -
fever, malaise (if you don't fight infection can lead to organ failure)
HAIs
-infections that patients acquire within healthcare setting that result from
treatment for other conditions
Exogenous HAI
-from microorganisms outside the individual
Endogenous HAI
-when the patient's flora becomes altered and an overgrowth results
(eg. an antibiotic is taken and kills good bacteria, but then the patient is susceptible)
, HAI risk factors
Number of health care employees with direct contact with the patient
Types and numbers of invasive procedures
Therapy received
Length of hospitalization
Major sites for HAI & risks
Surgical or traumatic wounds
Urinary (catheter) and respiratory tracts
bloodstream
Antibiotic Resistant super bugs?
-MRSA, VRE, C. Diff
Asepsis
-absence of pathogenic microbes
aseptic technique
-practices/procedures that assist in reducing the risk for infection
medical asepsis
-clean technique, includes procedures for REDUCING the number of organisms
present and preventing the transfer of organisms
surgical asepsis
-sterile technique, includes practices used to render and keep objects and areas
free from microorganisms
Principles of surgical asepsis
1. A sterile object remains sterile only when touched by another sterile object.
2. Only sterile objects may be placed on a sterile field.
3. A sterile object or field out of the range of vision or an object held below a
person's waist is contaminated.
4. A sterile object or field becomes contaminated by prolonged exposure to
air.
5. When a sterile surface comes in contact with a wet, contaminated surface,
the sterile object or field becomes contaminated by capillary action.
6. Fluid flows in the direction of gravity.
7. The edges of a sterile field or container are considered to be contaminated.