Emerging Infectious Diseases

Question 1

What percentage of human pathogens are zoonotic?

Answer 1

61%

Question 2

What percentage of emerging diseases are zoonotic?

Answer 2

75%

Question 3

What is an emerging disease?

Answer 3

A previously unknown disease that suddenly appears in a population or a known disease that suddenly appears in a new population.

Question 4

What is a re-emerging disease?

Answer 4

a known disease, previously on the decline, that is becoming more common and will likely continue to do so.

Question 5

How are emerging/reemerging diseases recognized?

Answer 5

they’re detected, investigated, and then there is a response.

Question 6

What are the 5 stages of cross species disease emergence?

Answer 6

1. agent only in animals
2. primary infection (animals to humans only).
3. limited outbreak (animals to humans, few human to human)
4. long outbreak (animals to human or human to human)
5. exclusive human agent (only from humans)

Question 7

How many pathogens have only one known host?

Answer 7

37.3%

Question 8

What are some examples of diseases where humans/other animals are dead end hosts (Stage 2)?

Answer 8

rabies, WNV, EEEV, WEEV, and Influenza H5N1

Question 9

What are some examples of diseases that represent stage 3 of cross species disease emergence?

Answer 9

Mycobacterium bovis, Nipah Virus

Question 10

What are some examples of diseases that represent stage 4 of cross species disease emergence?

Answer 10

SARS, Schmallenberg virus, “Swine Influenza”

Question 11

What are some examples of diseases that represent stage 5 of cross species disease emergence?

Answer 11

HIV/AIDS, measles, smallpox, dengue gever, yellow fever.

Question 12

What species exhibit the most concern for spillover events into people?

Answer 12

rats, bats, and non-human primates.

Question 13

What 2 things contribute to the risk of spillover?

Answer 13

virus-independent traits and virus-specific traits.

Question 14

What are the 4 main drivers to pathogen emergence?

Answer 14

land use changes, food and agricultural systems, environmental systems, and human behavior.

Question 15

What is happening with livestock production that is affecting disease transmission?

Answer 15

increased demand for meat production with fewer, larger livestock holdings. The production/output per animal is increasing.

Question 16

What does effect does intensive agriculture have on disease transmission?

Answer 16

A lot of genetically similar hosts, managed under the same conditions, will have the same susceptibility

Question 17

What are the determinants of emergence?

Answer 17

host susceptibility, pathogen, reservoir, and transmission.

Question 18

When are you likely to see the best transmission?

Answer 18

within a species.

Question 19

If a disease crosses between distantly related species, the resulting disease will be _______.

Answer 19

very different and often more severe.

Question 20

What causes the increase in probability of transmission from a reservoir to a new host?

Answer 20

increasing abundance of the reservoir, increasing pathogen prevalence in the reservoir, and increasing contact between the reservoir and the new host.