Fundamentals Chapter 22 Infection Control

light and bacteria

they grow best in dark environments, deep in wounds, under dressings, and inside the body. ultraviolet light is used to kill viruses from equipment

where do most pathogens prefer to live?

warm, moist, dark enviornments

droplet transmission

when the pathogen travels in water droplets expelled as an infected person exhales, talks, sneezes, or coughs. inhaled, enter eye, or through oral care when taking care of a patient

pandemic

wide spread epidemic, large number of people in a country or worldwide example: swine flu and malaria

reservoir

source of infection-place where pathogens survive and multiply. human body, animals, soil, water, food, and environmental surfaces contaminated water, garbage, soiled diapers, wound dressings

tertiary defenses from disease

specific immunity-the process by which the body "learns" to recognize and destroy certain pathogens they they have encountered before lymphocytes-cells involved in specific immunity b cell lymphocytes-grow in the red bone marrow t cell lymphocytes-mature in the thymus these molecules trigger an immune response called antigens

infection

successful invasion of and multiplication of the body by a pathogen

septicemia

symptomatic systemic infection spread via the blood

HAI's are:

the leading cause of complication in the healthcare setting, and one of 10 leading cause of death in the US

transient flora

normal microbes that a person picks up when coming in contact with objects or another person-can remove these from handwashing

moisture and bacteria

some bacteria need moisture while others do not spores-can allow them to live without water (bacillus and clostridium species)

healthcare associated infection (HAI)

infections associated with healthcare given at any setting such as: hospitals, home health care, long termcare, and ambulatory settings

why might a person be a MDRO?

-severe illness -previous exposure to antibiotics in the past -underlying diseases and conditions such as renal disease, insulin dependent diabetes, pvd, skin lesions, dermatitis -dialysis, urinary catheterization, intravenous lines -repeated contact with acute care and intensive care settings -age

infectious agent

...

stages of infection

1. incubation-the time between successful invasion into the body and the first signs and symptoms appearing. does not know they are infected yet 2. prodromal-first appearance of vague symptoms example: throat irritation, tired, slight fever 3. illness-stage marked by s/s of the specific disease 4. decline-the stage during which the patients immune defenses along with medical therapies successful reduce the number of pathogenic microbes. s/s begin to fade 5. convalescence repair and return to health as the remaining number of microorganisms approaches zero

once a pathogen enters the host, four factors determine whether the person ends of with an infection:

1. virulence-its power to cause disease 2. ability of the organism to survive in the host environment 3. number of organisms-the greater number, the more likely to cause disease 4. ability of the host defenses to prevent infection

Public organizations are know enacting laws to control and interpret HAI's such as:

CDC ANA the joint commision quality and safety education for nurses-qsen agency for healthcare research and quality-ahrq

humoral immunity: tertiary defenses

acts directly against the antigen helper t cells activate b cells to become plasma cells and produce antibodies, also called IG destroy by the following: -phagocytosis-signal leukocytes to phagocytes the pathogens which the antibodies are bound -neutralization-binding to the pathogens attachment sites, antibodies disable the pathogens machinery for adhering to and invading body cells -agglutination have two attachment sites, each antibody can attach to two phagogenic cells in a population. this allows the pathogens to "clump" together and, reducing their activity and increasing their likelihood that the group will be detected by leukocytes activation of complement and inflammation-antibodies trigger the complement cascade and stimulate the release of inflammatory chemicals to destroy the antigen

oxygen and bacteria

aerobic-must have oxygen to live and grow anaerobic-do not require oxygen for growth and may be killed by its presence

multi drug resistant or drug resistant (MDRO)

antibiotic resistance to treat infectious diseases.

normal flora

bacteria and microorganisms that already live on our body and cause no harm to us-staphylococcus bacteria normal flora in the intestine to aid in digestion thiamine riboflavin

bacteremia

bacteria in the blood

direct contact

between two people usually involves touching, kissing, or sexual intercourse

nutrients and bacteria

can grow on food left at room temperature can cause salmonella poisioning keeping things at low temperatures and cooking everything very hot to kill bacteria

latent infection

cause no symptoms for periods of time and decades. example: TB and HIV

examples of portals of entry

conjunctiva of the eyes, nares, mouth, urethra, vagina, anus, cuts, scrapes, surgical incisions

indirect contact

contact with a fomite, a contaminated object that transfers a pathogen sneeze or cough and touch a keyboard

primary infection

first infection that occurs in the patient

emerging infectious diseases

newly identified diseases, diseases occurring in different geographic areas, etc. pg. 609

primary defenses from disease

first line of defense -skin-normal skin flora prevent multiplication of disease -respiratory tree-mucous membranes help trap microbes, cilia-little hair like projections help trap and sweep upward from the lower airways eyes-lacrimal glands and lysozyme-produce tears and are antimicrobial enzymes mouth-saliva-lysosome washing away crap from teeth gastrointestinal tract-many pathogens are destroyed in the stomach due to gastric juices -genitourinary tract-mucus which adheres to pathogens to promote excretion of urine and stool. urine contains lysozyme

secondary infection

follow the primary infection

nosocomial infection

hospital-acquired infections

temperature and bacteria

ideal temp-95 degrees fahrenheit

resident flora

live and multiply harmlessly deep in the skin layers, permanent inhabitants of the skin and cant be removed by routine handwashing

chronic infection

long onset, long duration. chronic diseases-lyme disease

pathogens

microorganisms capable of causing disease bacteria, viruses, fungi, protozoa: helminths, prions-protein particles that cause neurological diseases

local infection

only infecting one part of the part example: upper respiratory infection, strep throat, uti of the urethra

vector

organism that carries a pathogen to a suspectible host, typically by biting or stinging, creating another portal of entry in the body example: mosquito and west nile virus

epidemic

outbreak of a disease that suddenly affects a large group of people in a geographic region

pH, enzymes, and bacteria

pH range between 5 and 8. can't survive in highly acidic environments.

exogenous healthcare related infections

pathogen acquired from the healthcare enviornment

endogenous healthcare related infection

pathogen arises from patients normal flora when some form of treatment that causes a normally harmless microorganism to infect the person example: yeast infection from antibiotics

portal of exit

pathogen exiting and resovior through body fluids like urine, blood, mucus, saliva, breast milk, feces, vomitus, semen, or other secretions cuts, bites, and abrasions-also a portal of exit but can be a portal of entry

systemic infection

pathogens invade the blood of lymph and spread throughout the body

carriers

people capable of defending themselves from active disease but harbor the pathogenic organisms within their bodies

susceptible host

person who is at risk for infection because of inadequate defenses against the invading pathogen. examples: age, compromised immune system, immune deficiency conditions

secondary defenses from disease

phagocytosis-phagocytes engulf and destroy pathogens neutrophils, esinophiles, monocytes complement cascade-set of blood proteins called complement triggers a release of chemicals that attack the cells membrane causing them to rupture-BASOPHILES inflammation-when inflammation occurs, blood vessels dilate, which allows blood, nutrients, oxygen, and chemicals to go to affected area fever-rise of core body temperature, increases metabolism, and inhibits the growth of pathogens in the body.

acute infection

short onset, short duration.-cold

chain of infection

six links, all must be present for the infection to be transmitted from one individual to another

airborne transmission

smaller organisms can float on air currents. through heating and air conditioning systems. example: measles and TB