infection control unit 5 pt care

infection

establishment and growth of a microorganism on or in a host

if the infection results in injury to the host, the host is said to have a…

disease

infection control

policies followed by health care workers that help the spread of disease

nosocomial infection

acquired in the course of medical care 

has the incidents of nosocomial infections increased over the past few decades?

yes

why have nosocomial infections been on the rise in the past few decades?

emergence of new diseases and an increase in organisms becoming resistant to antibiotics

what are the factors in nosocomial infections?

environment, therapeutic regimen, equipment, contamination

environment 

other patients that have diseases, visitors, contaminated food/equipment, air circulation, medical personnel

therapeutic regimen

the type of drugs the patient is taking which alter the normal flora and leads to a decreased resistance to other types of hospital germs

equipment

instruments that have not been adequately cleaned/sterilized

contamination

microorganisms transmitted through medical procedures if correct technique isnt used

susceptibility to nosocomial infections

age, heredity, nutritional status, stress, inadequate rest/exercise, health history, inadequate defenses, personal habits 

age

very young and very old people have less efficient immune systems

heredity

genetic/congenital conditions that make individuals more or less resistant to infection

nutritional stress

inadequate nutrient intake or an over abundance of intake, decrease resistance to infection

stress

physiological and psychological stress increases cortisone which lowers resistance to infection 

inadequate rest and exercise

lack of sleep/exercise which decreases blood circulation and lowers resistance to infection

health history 

diabetes, heart disease (greater risk for infection)

inadequate defenses

people with broken skin, burns, trauma, may have a suppressed immune system due to medication

personal habits 

smoking, drugs/alcohol, sexual practices 

microorganism

tiny form of life found in the environment and within all living things (plants, animals, humans)

microorganisms live in the…

air, on land, in water

TRUE/FALSE: all microorganisms cause disease and aren’t essential to our well-being

false

resident flora

microorganism that is beneficial to humans

pathogens

microorganisms that cause disease

main types of pathogens

bacteria, viruses, fungi, parasites, prions

bacteria 

microscopic one-celled organism with a typical nucleus 

TRUE/FALSE: bacteria carry only DNA 

FALSE: dna and rna 

morphology

bacteria that vary in size and shape

some bacteria survive in ______ conditions and can form a protective resting _________ that can germinate many years later 

harsh, endospore 

aerobes

can survive in an oxygen environment

anaerobes

cannot survive in an oxygen environment

which bacteria are beneficial?

probiotics (lactobacillus, bifidobacterium)

bacterial diseases

tuberculosis 

streptococcal (strep infections) 

staphylococcal (wound infections) 

salmonella 

gonorrhea and syphilis (venereal diseases)

tetanus (lockjaw) 

viruses

smallest, microscopic non-cellular organisms

viruses either contain ___ or ___, never both

DNA, RNA

viruses must _______ a host cell to survive and reproduce

invade

virion

viral particle that attaches to host cell and inserts its own genetic information, redirects host cell to produce new viruses

TRUE/FALSE: some viruses can invade and travel within the nervous system

TRUE

viruses can remain dormant after initial infection and then reappear multiple times later when the body…

is under stress (cold sore, shingles)

viral diseases

common cold (rhinovirus)

influenza

measles (rubeola) 

mumps (parotitis) 

rubella (german measles) 

Hepatitis A, B, C, D, E 

HIV (causes AIDS) 

HSV I (cold sores) 

HSV II (genital herpes) 

viral pneumonia

complication of the flu

fungi

multicellular (molds) or one-celled organisms (yeast) with a nucleus and membrane-bound organelles 

some fungi exist as mold or yeast, which can be classified as being….

dimorphic

fungi can be __________ or _____________

macroscopic, microscopic

in terms of genetic information, fungi contain ….

DNA and RNA

what kind of bacteria REQUIRES an aerobic environment to survive?

fungi

beneficial molds

antibiotics (penicillin), steroid drugs (cortisone), cheese, soy sauce

beneficial yeasts 

probiotics (saccharomyces boulardii), bread, beer, wine 

aspergillus

a type of mold (fungus) that includes allergic reactions and asthma

candida albicans

a type of yeast (fungi) thats a vaginal/intestinal yeast infection or/in the mouth, commonly known as thrush 

histoplasmosis, tinea, and tinea pedis

a type of dimorphic fungal disease thats contracted from bird/bat droppings, ringworm, athletes foot

parasites

organisms that live on/in a host organism and get their food from/at the expense of the host

three main classes of parasites that can cause disease in humans

protozoa 

helminths 

ectoparasites 

protozoa

one-celled complex microorganisms

how do protozoa have mobility?

through pseudopod formation (part of cell presses forward, rest follows), flagella (whip-like projections, a tail), cilia (small, hair-like projections) 

in terms of genetic material, what do protozoa contain?

dna and rna

what are some diseases caused by protozoa?

malaria (spread by mosquitos)

giardiasis (intestinal, contaminated water and feces) 

toxoplasmosis (cat-scratch fever, flu-like symptoms, dangerous in pregnancy; contaminated animal feces, water, and food) 

helminths

parasitic worms (flatworms, roundworms)

where are helminths found primarily?

in the human intestinal tract

what are some diseases caused by helminths?

enterobiasis (pinworm; feces)

trichinosis (contaminated water and undercooked meat such as pork, bear, horse, venison) 

diphyllobothrium latum (tapeworm; contaminated food/water) 

ectoparasites

organisms such as ticks, flea, lice, mites that burrow/attach into the skin and remain there for periods of time 

what are some diseases caused by ectoparasites?

scabies (mites, itching and rash)

lice (head and pubic — crabs) 

lyme disease (ticks — rash, muscle aches, fever) 

prions

mutated form of a normal protein found mostly in the central nervous system

in terms of genetic information, what do prions contain?

neither dna or rna

what are some diseases caused by prions?

transmissible spongiform encephalopathies (TSE) — fatal neurodegenerative diseases in animals/humans 

creutzfeldt-jakob (mad cow) disease — most common disease resulting from infection with prions, caused by eating infected meat 

major elements must be present to transmit infection

an infectious agent (bacteria, virus, fungi)

a reservoir/environment for them to multiply 

a portal from which to exit the reservoir 

a means of transmission 

pathogens vary in their

pathogenicity, virulence, invasiveness, specificity

pathogenicity

ability to cause disease

virulence

ability to grow/multiply with speed

invasiveness

ability to enter tissues

specificity

attraction to a particular host

reservoir 

environment for the microbes to live and multiply, living or not (human, animal, plant, water, food, earth)

carrier

person who serves as a reservoir

a portal from which to exit the reservoir

pathogens can leave the body through the mouth, nose, intestines, urinary tract, or an open wound 

a means of transmission

direct contact, indirect contact, droplet contact, airborne, vehicles

direct contact

an infected person directly touches another or their blood/body fluids

indirect contact

a person touches a contaminated object (fomites)

droplet contact

pathogens come in contact with the eyes, nose, mouth

airborne route

a person inhales residue from evaporated droplets of diseased microorganisms

vehicles and vectors 

food, water, drugs 

insects/animals

a portal of entry into a new host

pathogens enter new host through ingestion, inhalation, injection, across mucus membranes, and cross the placenta

establishment of infectious disease

encounter, entry, spread, multiplication, damage

encounter

pathogen comes in contact with host

entry

ingression or penetration of pathogen

spread 

pathogen attempts to overcome immune defenses 

multiplication

pathogen multiplies

damage

direct or indirect damage to cells

outcomes of an infectious disease

1. immune system of host gains control and eliminates pathogen 

2. pathogen overcomes immune system and causes disease in host 

3. pathogen and host compromise and live in a state of symbiosis 

immune system

human body protects itself from microbial invasion (mechanical, chemical, and cellular defenses) 

immunosuppressed/immunodepressed/compromised

a persons body that does not adequately defend itself against disease

a person that’s unable to neutralize, destroy, or eliminate invading microbes from their body is called….

immunosuppressed 

antigens

protein chemical markers that identify cells

all human cells and MOST pathogens have their own specific…

antigens

when a pathogen enters the body (or self-made like a malignant cell), it contains an antigen that is foreign. these foreign antigens will be recognized and…

destroyed 

antibodies

proteins produced by B cells (lymphocyte/wbc) in response to foreign antigens

antibodies do not destroy foreign antigens, but rather…

attach themselves to them and label them for destruction

each antibody produced in the body is specific to only ___ type of antigen

one

antibodies are produced in the body slowly and in small amounts when…

a person is first exposed to a foreign antibody

why do we usually “catch” a disease after the first exposure?

because the body cannot produce antibodies fast enough to prevent it