disease reservoirs Flashcards
what are the dynamics of disease transmission?
- host
- environment
- agent
- chain of transmission
how was cholera spread?
fecal oral & water
who first isolated anthrax?
robert koch
how did robert koch use anthrax?
used experimental infections of naive animals to prove that b. anthraces causes anthrax
-began modern germ theory
what was pasteur’s influence on epi?
developed and tested an early vaccine in sheep, goats, and cattle
what was typhoid mary’s influence?
- asymptomatic carrier
- worked as a cook that caused a salmonella typhi outbreak
what was walter reed’s influence on epi?
discovered yellow fever was transmitted by mosquitoes
T or F.
knowing the mod of transmission is more important than identifying the specific agent.
true
define reservoir
habitat where an infectious agent lives, grows, and multiplies
-can be human, animal, or environment
what questions must you answer in order to be considered a reservoir?
- naturally infected with the pathogen?
- can it maintain the pathogen over time?
- can it transmit the disease to a new and susceptible host?
who are the dead end hosts/accidental hosts & the reservoirs in trichenella?
- dead end/accidental: humans
2. reservoirs: pigs & bears
what is the reservoir for histoplasmosis?
droppings of birds and bats in the environment
where does histoplasmosis predominantly occur?
mississipi and ohio river valley
how did humans receive anthrax from hippos?
by eating them
what 2 animals are good at balanced pathogenicity? (have chronic infections with minimal symptoms)
bats & rodents
T or F.
all sick animals are reservoirs
false
T or F.
if theyre clinically ill & reservoir competent, then theyre probably infectious.
true
define vertical transmission & what are the types.
from reservoir host to offspring
- congenital: cross the placenta
- perinatal: during parturition via the colostrum
define horizontal tranmission & what are the types.
reservoir to new host
- direct: direct from reservoir or host
- indirect: via intermediary, animate, or inanimate object
what 3 major ways are classified as direct contact (horizontal).
- direct contact (ex. bite)
- direct projection->wet, large, and short range aerosols (sneezing, coughing)
* same room same time or within 5 m! - airborne (ex. foot & mouth disease)
what 2 major ways are classified as indirect contact?
- vehicle: inaminate object
2. vector: living organism
most vectors are ______
arthropods
when a vector transmits a disease, what are 2 ways they can do this?
- mechanical: agent DOES NOT multiply
2. biological: agent DOES multiply (these activities are required for its transmission)
t or f.
infectious always leads to a disease.
false
when you have a disease, this doesnt mean you always pass it on and infect others
