week 5- Infection, Infectious Disease and Epidemiology Resources Flashcards
Pathogenic
Can cause disease
microorganism that causes disease
called infectious
also called pathogenic
What are normal microflora?
MO that live on/in us that do not cause disease under normal circumstances
How do we obtain normal flora?
development in womb
during birthing process
during first few months of life
How can normal flora benefit us?
Protect againts pathogenic diseases
List areas of the body that normal microflora are normally found
skin
upper respiratory tract
GI tract
List areas of the body that normal microflora are NOT normally found
Blood
Lower respiratory tract/ alveoli
Bladder/urine
cerebrospinal fluid
Define “opportunistic” microbes/pathogens
microflora that under certain circumstances they can cause diseases
describe 3 ways normal microflora become opportunistic pathogens?
Normal flora go to unusual place in body that it shouldn’t be in
immunocompromised
imbalance of normal flora-disrupted
What are reservoirs of infection
where cells hang out until they find a human host
pathogens are maintained as a source of infection
3 types of reservoirs of infection
animals(dogs bats etc..)(zoonotic)
humans(carry in body, could be asympathetic)
nonliving reservoirs(soil)
What are the main portals of entry for a pathogen (how do pathogens get inside our bodies)
skin
mucous membranes- line body that are open to environment(mouth nose)-Respiratory tract
placenta-typically has protective barrier-some pathogens may enter and infect fetus
parenteral route-pathogens deposited directly into tissues beneath skin or mucous membrane
What will have to occur for a microbe to actually cause an infection (disease) in a person?
microbe must enter body
overcome host immune system
find place to multiply in host tissue
pathogenicity
ability to cause disease
virulence
how/degree of pathogenicity
can also be called pathogenicity factors
Exotoxins and endotoxin
EX- Secreted out of microorganism
END-alreafy in cell-gram negative cell wall
3 types of exotoxin
neurotoxin
enterotoxin
cytotoxin
What are the main types/categories of pathogenicity/virulence factors that microorganisms have?
Adhesion factors-proteins adhere or stick to cell
Extracellular enzymes-secreted out of microorganism
Production of toxins-endotoxin and exotoxins
2 other ways that microorganisms can cause the signs and symptoms of an infectious disease
antiphagocytic factors(antiimmune system)-capsules
cytotoxic-kill cells
enters immune system-causes inflammation and damages tissues
collagenase
breaks down collagen framework in tissues
hyaluronidase
digests hyaluronic acid (glue that holds cells together) to get to deeper tissue
coagulase
coagulates blood proteins (converts fibrinogen to fibrin)—providing a hiding place for bacteria in
a clot
hemolysin
lyses(breaks down) RBC
protease
Break down proteins(antibodies)
kinase
digest blood clots (digests fibrin)
cytotoxins
kill host cells in general or affect their function
neurotoxins
interfere with nerve cell function
enterotoxins
affect cells lining the GI tract
Capsules
contain chemicals normally found in the human body to trick immune system and avoid being
killed
Endotoxins
can cause fever, inflammation, diarrhea, hemorrhaging, and shock—found in Gram Negative
bacteria cell wall and released upon death or division of cell
Leukeocidins
chemicals capable of destroying phagocytic white blood cells (neutrophils)
Briefly describe 5 phases of infectious diseases (which phase only occurs in some infections?)
Incubation- time between infection and showing signs/syptoms
Prodromal phase(some)- time of general symptoms
illness-severe signs/symptoms
decline phase- symptoms go away
convalescence-no more signs or symptoms-repairing tissues
How can infections be transmitted? (briefly describe the three major categories/types of transmission
and give examples of each type)-Contact
(Direct- kiss, sex shake hands
(indirect- share glass, share toothbrush)
(respiratory droplets-sneeze)
How can infections be transmitted? (briefly describe the three major categories/types of transmission
and give examples of each type)-vehicle
Air-sneezing coughing sweeping dust
Water- inside of water
Food- spread in and on food
sharing food, water or air with something that has the virus can transmit it
How can infections be transmitted? (briefly describe the three major categories/types of transmission
and give examples of each type)-Vector
Bugs
Mechanical-spread virus present on their body to new host (fly)
biological-inside of bug-spread by biting like mosquito
Describe a nosocomial infection
Infections people acquire at the hospital
prevalence
Number of total cases
incidence
number of new cases
epidemic
Significant increase in cases in small area
pandemic
significant increase in cases in large area(country)
morbidity
disease state( morbidity rate is how many people have disease)
mortality
death (mortality rate is how many people died from disease)
