Exam 4 (Ch 20- Promoting Asepsis & Preventing Infection) Flashcards
Virally induced cancers
- Hodgkin’s Disease
- Kaposi’s sacoma
- Cervical cancer
Healthcare-associated infections (HAIs)
Refers to infections associated with healthcare given in any setting (e.g., hospitals, home care, long-term care, and ambulatory settings).
Nosocomial infections
Refers more specifically to hospital-acquired infections.
HAIs aggravate:
existing illness and lengthen recovery time. HAIs seriously increase healthcare costs and patient suffering. It is the 10th leading cause of death in the US
CDC goals for infection control
- Reduce catheter-associated adverse events by 50% in healthcare settigns
- Reduce targeted antimicrobial-resistant bacterial infection by 50%, preventing transmission in health care settings
AHRQ
Agency for Healthcare Research and Quality. Contains links to information, tools, and resources on HAIs.
The Joint Commission
Quality oversight agency. Standards of performance include extensive criteria describing what healthcare organization must do to minimize the risks of infection
QSEN
Quality and Safety Education for Nurses. Group of educators that was formed to address the challenge of preparing nurses with the competencies necessary to improve the quality and safety of their places of work.
Chain of infection
Process by which infections spreads. Made up of 6 links, all of which must be present for the infection to be transmitted form one individual to another.
Normal flora
Microorganisms that are beneficial or even essential for human health and well-being.
Normal flora in the intestine aid in:
Digestion and synthesize vitamin K, and release vitamin b12, thiamine, and riboflavin when they die. They also limit the growth of harmful bacteria by competing with them for available nutrients.
Two types of normal flora:
Transient and resident
Transient flora
normal microbes that a person picks up by coming in contact with objects or another person (e.g., when you touch a soiled dressing). You can remove those with handwashing.
Resident flora
Live deep in skin layers, where they live and multiply harmlessly. They are permanent inhabitants of the skin, and cannot usually be removed with routing hand washing. They are usually not harmful unless they enter the deep tissues or unless the patient is especially vulnerable to disease.
Pathogens
microorganisms capable of causing disease
Infection
successful invasion of the body by a pathogen
Largest groups of pathogenic microorganisms are:
bacteria, viruses, and fungi (which include yeasts and molds)
Less common pathogens are:
protozoa, helminthes (worms), and prions, which are infectious protein particles that cause certain neurological diseases.
Normal flora may become pathogenic if:
disease or injury permit them to enter body regions they do not normally inhabit
Once a pathogen gain entry into a host, 4 factors determine whether the person develops infection:
- Virulence of the organism
- Ability of the organism to survive in the host environment
- Number of organisms (the greater the number, the more likely they are to cause disease)
- Ability of the host’s defenses to prevent infection
Virulence
power to cause disease
6 links of the chain of infection
- Reservoir
- Portal of exit
- Mode of transmission
- Portal of entry
- Susceptible host
- Infectious agent
Reservoir
A source of infection: a place where pathogens survive and multiply. The human body is the most common reservoir for pathogens.
e.g. beside tables, chairs, or equipment. Other surfaces, such as sinks, toilets, bed rails, and bed linens
Carriers
Individuals that have no symptoms of disease, yet they serve as reservoirs and can past he disease to others.
Most pathogens prefer a
warm, moist, dark environment
To live and thrive in human, microbes must:
be able to use the body’s precise balance of food, moisture, nutrients, electrolytes, pH, temperature, and light. Food, water, and soil that provide these conditions may serve as nonliving reservoirs, as well.
Bacteria can rapidly multiply in food left at
room temperature
The bacteria Salmonella enteritis, which causes salmonellosis can multiply in:
raw and undercooked meat and eggs
To prevent the growth of pathogens, many foods are:
cooked at high temps and stored in a cool environment. Alternatively, many foods are prepared with a concentration of solutes that inhibits the growth of pathogenic microbes i.e salting of meats and the production of fruit jellies, jams, and preserves
Pathogens require _____ for survival
moisture
e.g. the moist environment of wounds, the genitourinary tract, the throat and airways
The spore formed by some bacteria allow them to live without ____.
water
e.g. bacillus and clostridium species; both are food-borne diseases
For most pathogens, the ideal temperature is ___
95 degrees F (35 degrees C)
Environments that are either too hot or too cold for a particular species will:
slow its growth or even kill the entire population
The microbes that are pathogenic to humans are so because
they thrive at about the same temperature as the human body; thus, a fever in response to infection can inhibit and even kill invading pathogens
Many bacteria and most protozoa and fungi are ___.
aerobic. They must have oxygen to live and grow.
e. g. yeast Candida albicans causes infection in the oral mucosa (“thrush”) and the vaginal muscosa
Anaerobic organisms
Do not require oxygen for growth and may even be killed in its presence.
e.g. Clostridium tetani, a spore-forming bacterium, which causes tetanus when a spore enters the body through an open wound
To live in humans, pathogens need
the body’s precise balance of moisture, sugars, pH (acidity), and electrolytes.
Most pathogens prefer a pH range of ____ to _____.
5 to 8. therefore, they cannot survive in the highly acidic environment of the stomach.
When patients take antacids, stomach pH increases and removes this defense.
Microbes that have a higher or lower pH and electrolyte concentration than the human body are not
pathogenic to human beings
Microbes grow best in
dark environments (e.g., inside the body, deep in wounds, and under dressings)
Ultraviolet light is sometimes used to
remove pathogens such as staphylococcus, salmonella, and viruses from surgical instruments and other objects. It can also be used to disinfect drinking water in developing countries to prevent diseases such as cholera and typhoid fever
A contained reservoir is only a ___ source of infection.
potential
For infection to spread, a pathogen must
exit the reservoir
Portal of exit
In the case of human or animal reservoirs, the most frequent portal of exit is through body fluids, including blood, mucus, saliva, breast milk, urine, feces, vomitus, semen, or other secretions.
The body’s natural response to foreign materials, including pathogens, is to try to ___ them.
expel.
e.g. If you have a pathogen in the respiratory system, you cough or sneeze. If it’s in the gastrointestinal system, you vomit or experience intestinal cramping and diarrhea.
Cuts, bites, and abrasions provide
an exit for body fluid
Blood and pus seeping from a wound help
transport pathogens away from the broken skin but become a portal by which infection may be transmitted to others.
In healthcare-related infections, puncture sites, drainage tubes, feeding tubes, and intravenous lines commonly serve as
routes for pathogens to exit the body
The most frequent mode of transmission of infection is by
contact, either direct or indirect
Direct contact
involves touching, kissing, or sexual intercourse. Animals commonly transmit infection via scratching and biting as well.
Indirect contact
Involves contact with a fomite
Fomite
a contaminated object that transfers a pathogen
Droplet transmission
Occurs when the pathogen travels in water droplets expelled as an infected person exhales, coughs, sneezes, or talks. It may also occur during suctioning and oral care.
The usual method of droplet transmission
droplet to be inhaled or enter the eye of a susceptible person.
Droplets can travel only ___ from the infectious person
a few feet; within that distance they may readily contaminate fomites that then transmit the organism by contact
Airborne transmission
Occurs with much smaller organisms that can float considerable distances on air currents.
Airborne pathogens can travel through
heating and air conditioning systems to infect large numbers of people
Sweeping a floor or shaking out contaminated bed linens can stir up
airborne microorganisms and launch them on air currents. Agents of measles and tuberculosis, as well as many fungal infections, are commonly transmitted in this manner.
Vector
An organism that carries a pathogen to a susceptible host, typically by biting or stinging, creating another portal of entry into the body.
e.g. mosquitos, ticks, fleas, mites, and other insects
Portals of entry
normal body openings, such as the conjunctiva of the eye, the nares, mouth, urethra, vagina, and anus
Potential portals of entry
Abnormal openings, such as cuts, scrapes, and surgical incisions.
Common portals of entry include:
wounds, surgical sites, and insertion sites for tubes or needles
Susceptible (or compromised) host
A person who is at risk for infection because of inadequate defenses against the invading pathogen.
