Class Final Flashcards
Pathology
study of disease
Pathogenesis
manner in which a disease develops
Infection
invasion or colonization of the body by pathogenic microorganisms
Disease
change from a state of health
Normal flora
microbiota, microorganisms that carry out normal processes
Transient microbiota
live in or on you for a while and then leaves
-group b strep
opportunistic pathogens
normal flora given the right opportunity can be infectious
signs
what you can see/measure
symptoms
what the patient feels
incubation
bacteria growing but you have no signs and symptoms
prodromal stage
symptoms but very general
illness stage
characteristic symptoms
period of decline
illness declines
period of resolution
illness is basically gone
three types of spread
communicable, contagious, noncommunicable
communicable
can be passed
contagious
can be passed very readily
noncommunicable
cannot be passed from person to person
Sporadic
no real pattern
endemic
constantly present
epidemic
disease occurring in excess of normal epidemic
pandemic
worldwide epidemic
Acute
rapid onset, rapid clearing
chronic
slow onset, last very long
latent
show symptom, periods in-between
Local infection
strep, cut, old
systemic infection
whole body
primary infection
first infection followed by secondary
subclinical or asymptomatic
carrier of pathogen without symptoms, chronic
Nosocomial infection
infection contracted at a hospital
Germ theory
Robert Koch, worked with bacillus anthrax
five requirements for pathogens to be pathogenic
entry, attachment, survival, damage, exit
portal of entry
mucus membrane, skin, parental routes (punctures)
Virulence factors
factors that contribute to a pathogens success and ability to cause disease
Ebola
Etiology: Ebola virus
Reservoir: animals like bats, humans
Transmission: direct contact of fluids
Signs and Symptoms: fever, severe headache, fatigue, unexplained hemorrhaging. Symptoms may appear anywhere from 2-21 days
Treatment and Prevention: sustaining individual until they can fight off the virus i.e fluids, oxygen, and blood pressure medication
-prevent contact with infected individuals
HIV
Etiology: Human immunodeficiency virus 1 and 2, enveloped
Reservoir: Humans
Transmission: sexual contact or contaminated needles
Signs and Symptoms:2-4 weeks brief flu symptoms, enters latent stage, can develop AIDS within 10 years down the road
Treatment and Prevention: safe sex, anti-retroviral drug therapy
HPV
Etiology: Papillomaviridae
Reservoir: Humans
Transmission: sexual contact of contact with contaminated fluids
Signs and Symptoms: commonly asymptomatic, genital warts, some develop into cancer
Treatment and Prevention: vaccines Cervarix and Gardasil, safe sex
MRSA
Etiology: Methicillin-resistant Staphylococcus aureus, gram positive, non-motile, staphylococcal, produces endotoxin
Reservoir: humans
Transmission: objects contaminated with human flora, skin to skin contact, sharing personal items, open wounds
Signs and Symptoms: red, swollen, pus filled lesion on skin, painful, Often confused with spider bite
Treatment and Prevention: drainage of pus, antibiotic NOT in penicillin family.
-avoid sharing personal items and keep wounds clean
The Cold
Etiology: Rhinovirus, naked virus, very very small, 100 different serotypes
Reservoir: humans
Transmission: 1 virus can cause infection, confined to upper respiratory tract, droplets and direct and indirect contact
Signs and Symptoms: flu like symptoms
Treatment and Prevention: fluids and rest, wash hands and be cautious when around sick people
The Flu
Etiology: Influenza virus, 2 different protein spikes- Hand N, 8 segments which allows for reassortment
Reservoir: humans, can come from animals from antigenic shift
Transmission: droplets, fomites, confined to upper respiratory system
Signs and Symptoms: flu symptoms
Treatment and Prevention: liquids, rest, vaccine, Tamiflu within 24-48 hours of infection
Pneumonia
Etiology: streptococcal pnemoniea, gram positive, coccal, polysaccharide capsule
Reservoir: humans
Transmission: opportunistic pathogen, secondary infection
Signs and Symptoms: mucus in lungs, flu symptoms
Treatment and Prevention: antibiotics, maintaining healthy flora
Attachment
fimbriae and capsules
Anti-phagocytic structures
capsule, cell walls
Damage
enzymes, endotoxins (LPS), exotoxins
Exoenzymes
released from cells and damage host tissues
- Luekocidins- kill white blood cells
- Hemolysins- cause the lysis of RBC’s
Hemolysins
- beta hemolysin-complete breakdown of red blood cell
- alpha hemolysin- incomplete breakdown of red blood cells
Enzymes
streptokinase/staphylokinase, coagulase, collegenase, Hyaluronidase
Streptokinase/staphylokinase
breaks down blood clots
Coagulase
cause the formation of blood clots
-almost all pathogenic strains of s. aureus produce this enzyme
Collegenase
breaks down collagen
-produced by clostridium perfringens that cause gas gangrene
Hyaluronidase
breaks down connective tissue
- facilitates spread and causes damage
Exotoxins
substances released from bacteria that damage tissue
Erythrogenic toxins
damage cells lining capillaries and cause blood to leak out under skin
-scarlet fever
enterotoxins
cause damage to gastrointestinal tract
-caused by an electrolyte imbalance causing water to flow into large intestine which results in diarrhea
What cause the most damage?
toxins and enzymes
What makes an enzyme?
If it catalyzes a chemical reaction
What makes a toxin?
If it binds to a receptor
Neurotoxins
inhibit the normal functioning of the nervous system
- tetanus toxin blocks inhibitory nerve impulses that allow muscles to relax
- botulinum toxin inhibits the functioning of motor neurons causing flaccid paralysis (muscles can’t contract)
Super Antigens
toxins that cause major damage to the host
-toxic shock syndrome caused by super antigen produced by staphylococcus aureus
Endotoxin
lipid A portion of lipopolysaccharide causes
- fever
- shock
- rash
Damage from the immune response
cross-reactive antibodies and strep throat
- can lead to rheumatic fever
- some pathogens cause damage by stimulating an excessive immune response
Epidemiology
the study of when a where diseases occur
- how they are transmitted
- what the etiology (cause) is
- how they can be controlled
Morbidity
state of being diseased
Mortality
death
CDC
Center for disease control and prevention, nations center for epidemiology
-tracks infectious diseases nationwide
WHO
worldwide health organization overseen by UN
John Snow
Cholera outbreak, Broadstreet in London, took the handle off of the spout
Mechanisms of transmission
from one person to another
- direct - STD
- indirect -fomite
- droplet
Vehicle transmission
transmission of disease by water, food, or air
Vector transmission
fomites, insects
