ecology of human infectious disease

Question 1

what are the types of agents in human infectious diseases?

Answer 1

• bacterial
• viral
• fungal
• parasitic

Question 2

what is the epidemiological triad?

Answer 2

Host (who has the disease) -environment (factors that allow for transmission) - agent (microbe that causes disease)
+ vector (organism that carries and transmits pathogen to host)

Question 3

what are zoonoses (zoonotics)?

Answer 3

diseases and infections of vertebrate animals that can be transmitted to humans

Question 4

what are the types of zoonotic diseases?

Answer 4

emerging (newly appear in humans) or endemic (occur intermittently, triggered by events)

Question 5

what is zoonotic spillover?

Answer 5

the transmission of pathogens from wild animals to humans

Question 6

what are the seven major anthropocentric drivers of zoonotic disease emergence?

Answer 6

1. increasing demand for animal protein
2. unsustainable agricultural intensification (animals more vulnerable to infection)
3. increase use and exploitation of wildlife
4. unsustainable utilization of natural resources acceleraed by urbanization, land use change, extractive industries
5. travel and transportation
6. changes in food supply chains (difficult to trace)
7. climate change (thrive in warmer, wetter temperatures)

Question 7

what are the two ways that viruses evolve?

Answer 7

• antigenic drift: point mutations cause small changes in the surface antigens (H and N) -> causes regional epidemic in populations with no previous exposure
• antigenic shift: process by which the whole H-N combination changes because large pieces of genome are exchanged between viruses attacking the same cell -> can cause pandemic