disease reservoirs

Question 1

what are the dynamics of disease transmission?

Answer 1

1. host
2. environment
3. agent
4. chain of transmission

Question 2

how was cholera spread?

Answer 2

fecal oral & water

Question 3

who first isolated anthrax?

Answer 3

robert koch

Question 4

how did robert koch use anthrax?

Answer 4

used experimental infections of naive animals to prove that b. anthraces causes anthrax
-began modern germ theory

Question 5

what was pasteur’s influence on epi?

Answer 5

developed and tested an early vaccine in sheep, goats, and cattle

Question 6

what was typhoid mary’s influence?

Answer 6

• asymptomatic carrier

- worked as a cook that caused a salmonella typhi outbreak

Question 7

what was walter reed’s influence on epi?

Answer 7

discovered yellow fever was transmitted by mosquitoes

Question 8

T or F.

knowing the mod of transmission is more important than identifying the specific agent.

Answer 8

true

Question 9

define reservoir

Answer 9

habitat where an infectious agent lives, grows, and multiplies
-can be human, animal, or environment

Question 10

what questions must you answer in order to be considered a reservoir?

Answer 10

1. naturally infected with the pathogen?
2. can it maintain the pathogen over time?
3. can it transmit the disease to a new and susceptible host?

Question 11

who are the dead end hosts/accidental hosts & the reservoirs in trichenella?

Answer 11

1. dead end/accidental: humans

2. reservoirs: pigs & bears

Question 12

what is the reservoir for histoplasmosis?

Answer 12

droppings of birds and bats in the environment

Question 13

where does histoplasmosis predominantly occur?

Answer 13

mississipi and ohio river valley

Question 14

how did humans receive anthrax from hippos?

Answer 14

by eating them

Question 15

what 2 animals are good at balanced pathogenicity? (have chronic infections with minimal symptoms)

Answer 15

bats & rodents

Question 16

T or F.

all sick animals are reservoirs

Answer 16

false

Question 17

T or F.

if theyre clinically ill & reservoir competent, then theyre probably infectious.

Answer 17

true

Question 18

define vertical transmission & what are the types.

Answer 18

from reservoir host to offspring

1. congenital: cross the placenta
2. perinatal: during parturition via the colostrum

Question 19

define horizontal tranmission & what are the types.

Answer 19

reservoir to new host

1. direct: direct from reservoir or host
2. indirect: via intermediary, animate, or inanimate object

Question 20

what 3 major ways are classified as direct contact (horizontal).

Answer 20

1. direct contact (ex. bite)
2. direct projection->wet, large, and short range aerosols (sneezing, coughing)
   * same room same time or within 5 m!
3. airborne (ex. foot & mouth disease)

Question 21

what 2 major ways are classified as indirect contact?

Answer 21

1. vehicle: inaminate object

2. vector: living organism

Question 22

most vectors are ______

Answer 22

arthropods

Question 23

when a vector transmits a disease, what are 2 ways they can do this?

Answer 23

1. mechanical: agent DOES NOT multiply

2. biological: agent DOES multiply (these activities are required for its transmission)

Question 24

t or f.

infectious always leads to a disease.

Answer 24

false

when you have a disease, this doesnt mean you always pass it on and infect others

Question 25

define the 3 types of carriers: incubatory, convalescent, and latent.

Answer 25

1. sick before they show signs
2. shed even when theyre over the disease
3. carry the disease for long periods of time

Question 26

what type of transmission is lyme disease?

Answer 26

horizontal; indirect (because its going through a vector)

Question 27

what type of transmission is west nile virus?

Answer 27

horizontal; indirect (mosquitoes are the vectors)

Question 28

for west nile, who is the accidental and dead end hosts?

Answer 28

humans and horses

Question 29

define index case

Answer 29

first case that came to the attention of the health authorities (not the literal first case)

Question 30

when you have an outbreak, whats the very first thing as an epidemiologist you want to do?

Answer 30

explore and look around the environment

Question 31

how can tularemia be transmitted?

Answer 31

• drinking water & food (ingestion)
• inhalation
• direct contact with broken skin
• vectors