infection control Flashcards
what is disease
Absence of health
Any deviation from or interruption of the normal
structure or function of any part, organ, or system (or
combination thereof) of the body.
what is infection
- Establishment and growth of a microorganism on or in
a host, resulting in injury to the host. - Caused by pathogenic organisms (a biological
agent that causes disease in its host).
what 3 things do pathogens do
- Multiply
- Secrete organic exotoxins (primarily by bacteria) as part of their growth and metabolism
- Cause tissue damage
what are exotoxins
- Exotoxins are proteins that cause damage or
dysfunction, by damaging host cell membranes or by
entering target cells and directly altering function. - Exotoxins cause side effects – fever, nausea, vomiting
etc.
what are the 4 types of pathogens
- Bacteria
- Viruses
- Fungi
- Parasitic protozoa
what are bacteria
- Microscopic, single-celled organisms.
- Prokaryotes - lack nuclei and membrane-bound organelles.
- May reside in host as a group or cluster called a colony.
- May be classified according to their morphology (size &
shape), biochemistry or genetic constitution. - Medically important bacteria are classified morphologically:
cocci or spheres, bacilli or rods, and spirals.
what are endospores
- Most often produced due to nutritional deprivation.
- Metabolically dormant and highly resistant to external environment, chemical and physical agents.
- Remain viable for many years and then germinate in response to specific requirements.
Streptococcal pharyngitis (Strep throat)
bacterial
Klebsiella pneumonia (Bacterial pneumonia)
bacterial
- Clostridium botulinum (Food poisoning)
bacterial
- Salmonella typhimurium (Salmonellosis)
bacterial
how are bacterial infections often treated
antibiotics
viruses
- Microscopic, single celled.
- Cannot live outside a living cell - lack components for their own survival;
inability to synthesize specific required proteins - Carry their own DNA or RNA but never both. DNA and RNA are
surrounded by protein coat known as capsid. - Classified by the chemical nature of their nucleic acid, size and symmetry.
- Virion (viral particle) attaches to host cell, inserts its own genetic
information, and then redirects host cell to produce new viruses. - Not affected by antibiotics.
HIV1 and HIV 2
viral
Rhinovirus (Common cold)
vural
Human Papillomavirus
viral
Human Papillomavirus causes what
(Warts; Genital Warts, Cervical &
Anal Cancer)
Epstein-Barr virus (Mononucleosis)
viral
SARS-CoV-2 (COVID-19)
viral
what are fungi
- Macroscopic or microscopic.
- Eukaryotic (has nucleus and membrane-bound organelles).
- Much larger than bacteria
- Medically important fungi are dimorphic.
- Two forms: yeast aka candida (single celled) or molds
depending on growth conditions. - Classified according to type and method of sexual reproduction.
what are the 4 fungi classification
superficial
cutaneous
subcutaneous
systemic
superficial ex
tinea negra
discoloration of palmar or plantar surface
cutaneous ex
tinea pedia -athletes foot
systemic ex
systemic candidiasis ie candidemia
what are parasitic protazoa
- Unicellular organisms that are neither plant nor animal.
- Larger than bacteria
- Eukaryotic
- Can ingest food particles, and some are equipped with
digestive systems. - Live on or in other organisms at expense of host.
what are the 4 parasitic protazoa classifications
ameboid
flagellum
cilia
sporozoans
ex of 2 parasitic protazoa that form cysts
trichomonas vaginalis
plasmodium vivax (malaria)
what is the chain of establishment of infectious diseases
encounter
entry
spread
mulitplication
damage
outcome
describe encounter
infectious organism interacts with host
describe entry
access through a portal of entry
(respiratory, digestive, urinary)
what are the 2 types of entry
ingression (attach to cell surface and excrete toxins)
penetration (pathogens invade past the epithelial barrier
describe spread
propagation of IO
requires overcoming body’s immune defenses
describe multiplication
happens during the incubation period (invasion to noticed by host)
exponential growth
describe damage
direct -cell death from destruction or toxin release
indirect - caused by alteration fo hosts metabolism
what are the 4 parts of the chain of infection
host
infectious microorganism
mode of transmission
reservoir
describe host
needs portal of entry
favourable environment for growth
suitable temperatures and pH
what are the 2 modes of tranmission
exogenous and endogenous
how does exogenous transmission occur
droplet (3-5feet)
airborne
touching a fomite
through a vector (insect/animal carrier)
what is the reservoir
site where the organism can remain alive, multiply and where transmissions can occur
what is a reservoir with no symptoms
a carrier
what are 2 types of HAI
nosocomial (facility acquired or at birth)
larogenic (from an intervention)
what are 5 sources of HAIs
medical personnel
patient flora
contaminated health care environments
invasive procedures
blood-borne pathogens
describe MRSA/VRSA
penicillin resistant
colonizes on skin and in nose
patients on isolation precautions
describe VRE
normal Flora of GI or skin
among immunocompd pts
infection in blood, urine, wounds
pts isolation precaution
describe Cdiff
caused by antibiotics that disrupt the normal GI
diarrhea to colon inflamm
spreads through feces and spores can persist for weeks or months
pts isolation precaution
what are standard precautions
hand washing
PPE
when do you use gloves ppe
contact with blood, fluids contaminated areas, non intact skin
when to wear face protection
anything likely to generate a splash of blood, body fluid, secretions, or excretions
what are 2 common antispetics
alcohol and betadine
what is tier 2 and when is it used
transmission based precautions
designed to place a barrier to the spread
what are the contact precautions
gloves and gown
what are the droplet precautions
surgical mask, eye protection, gown & gloves
pt wears surgical mask when leaving the room
what are the air-borne precautions
n95 fit tested mask
pt wears surgical mask
negative pressure isolation room
what is the sequence to PPE removal
gloves
face shield and goggles
gown
cap
mask
what are the five moments for hand hygiene
- Before touching a patient
- Before a clean aseptic procedure
- After body fluid exposure risk
- After touching a patient
- After touching patient surroundings
what are 3 airbornes
measles
varicella
tuberculosis
what are 3 droplet exmaples
influenza
meningitis
bordetella pertusis
what are contact precautions examples
MRSA
VRE
Cdiff
