Emerging Infectious Diseases Flashcards
What percentage of human pathogens are zoonotic?
61%
What percentage of emerging diseases are zoonotic?
75%
What is an emerging disease?
A previously unknown disease that suddenly appears in a population or a known disease that suddenly appears in a new population.
What is a re-emerging disease?
a known disease, previously on the decline, that is becoming more common and will likely continue to do so.
How are emerging/reemerging diseases recognized?
they’re detected, investigated, and then there is a response.
What are the 5 stages of cross species disease emergence?
- agent only in animals
- primary infection (animals to humans only).
- limited outbreak (animals to humans, few human to human)
- long outbreak (animals to human or human to human)
- exclusive human agent (only from humans)
How many pathogens have only one known host?
37.3%
What are some examples of diseases where humans/other animals are dead end hosts (Stage 2)?
rabies, WNV, EEEV, WEEV, and Influenza H5N1
What are some examples of diseases that represent stage 3 of cross species disease emergence?
Mycobacterium bovis, Nipah Virus
What are some examples of diseases that represent stage 4 of cross species disease emergence?
SARS, Schmallenberg virus, “Swine Influenza”
What are some examples of diseases that represent stage 5 of cross species disease emergence?
HIV/AIDS, measles, smallpox, dengue gever, yellow fever.
What species exhibit the most concern for spillover events into people?
rats, bats, and non-human primates.
What 2 things contribute to the risk of spillover?
virus-independent traits and virus-specific traits.
What are the 4 main drivers to pathogen emergence?
land use changes, food and agricultural systems, environmental systems, and human behavior.
What is happening with livestock production that is affecting disease transmission?
increased demand for meat production with fewer, larger livestock holdings. The production/output per animal is increasing.
What does effect does intensive agriculture have on disease transmission?
A lot of genetically similar hosts, managed under the same conditions, will have the same susceptibility
What are the determinants of emergence?
host susceptibility, pathogen, reservoir, and transmission.
When are you likely to see the best transmission?
within a species.
If a disease crosses between distantly related species, the resulting disease will be _______.
very different and often more severe.
What causes the increase in probability of transmission from a reservoir to a new host?
increasing abundance of the reservoir, increasing pathogen prevalence in the reservoir, and increasing contact between the reservoir and the new host.
