Disease Reservoirs and Transmission Flashcards Preview

RUSVM Epi Summer 2017 > Disease Reservoirs and Transmission > Flashcards

Flashcards in Disease Reservoirs and Transmission Deck (21)
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1
Q

Disease transmission is a result of what?

A

interaction between the host, agent, and environment. It can be multiple agents, hosts, or environments.

2
Q

Can you get different outcomes if it is the same host and agent?

A

Yes because every exposure is unique.

3
Q

What was John Snow’s role in the cholera outbreak?

A

He mapped out who was sick and where and found out the cholera was transmitted by the oral-fecal route and by the water supply.

4
Q

Who first isolated B. anthracis?

A

Roberth Koch. He proved the bacterium caused anthrax by infecting naive animals.

5
Q

Who is typhoid Mary?

A

Irish immigrant cook who had typhoid outbreaks following her wherever she went.

6
Q

Who discovered that malaria is transmitted by mosquitoes?

A

Ronald Ross.

7
Q

Who discovered that yellow fever is transmitted by mosquitoes?

A

Walter Reed.

8
Q

Who rid Havana and the Panama Canal from Yellow fever?

A

William Gorgas

9
Q

In disease transmission, what is (generally) the most important thing to know?

A

the mode of transmission.

10
Q

What is a reservoir?

A

habitat in which an infectious agent normally lives, grows, and multiplies. Doesn’t have to be an animal or person.

11
Q

What are the 3 main requirements to be considered a reservoir?

A
  1. naturally infected with the pathogen.
  2. maintains the pathogen over time
  3. this source can transmit the disease to a new, susceptible host.
12
Q

What makes reservoirs elusive?

A

They don’t always show clinical signs, cant prove persistence of infection, and transmission can be sporadic.

13
Q

T/F: all sick animals are reservoirs

A

False. Some can be carriers.

14
Q

What is vertical transmission?

A

from a reservoir host to its offspring. Can be congenital (crossing the placenta, infecting eggs) or perinatal (during parturition, via colostrum).

15
Q

What is horizontal transmission?

A

from the reservoir to a new host. Can be direct or indirect.

16
Q

What are some ways of direct horizontal transmission?

A

direct contact (skin to skin, sexually), direct projection (droplet spread), or airborne.

17
Q

What are some ways of indirect horizontal transmission?

A

via a vehicle or a vector

18
Q

What is a vehicle?

A

an inanimate object which serves to communicate disease

19
Q

What is a vector?

A

a living organism that serves to communicate disease (tick, mosquito, etc.)

20
Q

What are some types of vehicles?

A

common vehicle like food, water, contaminated IV drugs, or fomites.

21
Q

What is the difference between a mechanical and biological vector?

A

a mechanical vector does not have the agent multiply or undergo part of its life cycle while in/on the arthropod.