Disease Ecology

Question 1

what is considered a disease?

Answer 1

an Atypical condition in living organism that causes some sort of physiological impairment

Question 2

Zoonotic diseases

Answer 2

diseases that are transmitted from animals to humans

Question 3

Nipah virus

Answer 3

Is an RNA virus
jumped from bats to pigs to humans
high fatality rate because we did not coevolve

Question 4

Lyme disease

Answer 4

-white footed mice are reservoir for disease, spreading disease to many tics
-mice populations usually kept in check by predators but no forests for predators bc of deforestation

Question 5

malaria

Answer 5

-transmitted via mosquito bites, in low latitudes
-hella fuckin cases
-

Question 6

disease ecology

Answer 6

host-pathogen interactions within the context of their environment and evolution

Question 7

what are the goals of disease ecology? (2)

Answer 7

1) understand pathogen transmission and spread over time and space
2)impacts of host populations

Question 8

all disease causing organisms are:
what does it do to donor and recipient

Answer 8

Selfish
donor: + fitness recipient: - fittness
exploitative

Question 9

infectious diseases are not transmitted between hosts;

Answer 9

the pathogens/ parasites that cause diseases are

Question 10

Direct transmission

Answer 10

direct contact between hosts

Question 11

Indirect transmission

Answer 11

indirect transfer of infectious agent: fomites, airborne, animal vectors

Question 12

Horizontal transmission

Answer 12

transmission within same generation

Question 13

Vertical Transmission

Answer 13

parent to offspring before or during birth

Question 14

how do viruses replicate inside cells (steps)

Answer 14

1. virus binds to cell and enters
2. virus delivers its genome to site where it can reproduce new copies of viral protein and RNA
3. viral protiens and RNA burst through cell wall,

Question 15

influenza horizontal or vertical?

Answer 15

horizontal

Question 16

3 vertically transmitted diseases

Answer 16

zika, chickenpox, HIV

Question 17

What is the RNA virus repsonsible for the disease COVID 19?

Answer 17

SARS-CoV-2

Question 18

What transmission is relatively unaffected by host density?

Answer 18

frequency dependent transmission

Question 19

The per capita rate at which susceptible individual becomes infected increases with

Answer 19

fraction of host pop that is infectious BUT DOES NOT INCREASE WITH OVERALL DENSITY

Question 20

what is an example of a vector borne pathogen?

Answer 20

STDs

Question 21

Endemic

Answer 21

constant presence, however low spread

Question 22

Epidemic

Answer 22

High spread, only certain reasons

Question 23

Pandemic

Answer 23

global epidemic

Question 24

What is R0 in pathogens

Answer 24

the relative reproductive ratio of a pathogen
describes the initial growth of a pathogen in previously unexposed host population

Question 25

beta=

Answer 25

transmission rate probability for infection

Question 26

N=

Answer 26

number of host available for infection

Question 27

weird V- nu =

Answer 27

virulence- disease induced death rate of hosts

Question 28

d=

Answer 28

natural death rate of host

Question 29

r=

Answer 29

recovery of host

Question 30

how do we interpret R0

Answer 30

the average number of people who will be infected by 1 person with a disease, has certain assumptions

Question 31

assumptions for R0

Answer 31

-naiive population -everyone is susceptible in pop -no vaccinations- transmission interventions

Question 32

when R0 > 1

Answer 32

disease is increasing

Question 33

When R0< 1

Answer 33

disease in decline

Question 34

What is a dimensionless metric? meaning it does not refer to a specific time window?

Answer 34

R0

Question 35

What does R0 get replaced with once disease starts to spread?

Answer 35

Re and Rt effective reproduction number

Question 36

what does R0 inform us? what does it not inform us of?

Answer 36

how much the disease spreads and how hard it is to contain does not inform us of virulence: ability to damage host

Question 37

are R0 Re and Rt constants?

Answer 37

no, they vary from place to place and vary from time to time

Question 38

What are compartments?

Answer 38

subpopulations of the host

Question 39

what do compartment models do?

Answer 39

help epidemologists stop the spread

Question 40

can different diseases have different compartment models?

Answer 40

yes

Question 41

How do we slow disease?

Answer 41

behavioural changes herd immunity(vaccinations)

Question 42

Behavioural changes: isolation vs quarantine

Answer 42

isolation: separate sick individuals from healthy quarantine: separate individuals who have been exposed, even if not showing symptoms

Question 43

when does herd immunity occur?

Answer 43

when immunity rates are high enough that pop growth rate (r) of pathogen is negative, it might go extinct

Question 44

herd immunity threshold-

Answer 44

H miinimum percent of pop that must be immunized to reach herd immunity

Question 45

what is the coorelation between R0 and H

Answer 45

the higher the R0- the higher the H must be- because higher contagious pathogens spread fast

Question 46

why do pathogens hurt hosts? if they rely on them? (virulence)

Answer 46

because parasites that replicate too slowly do not produce sufficient transmission stage, replicate too quickly will kill their host before transmission selection favours pathogens with intermediate levels of within host transmission

Question 47

strategies for combating infection: tolerance vs resistance

Answer 47

tolerance: ability for host to tolerate infection by minimizing damage done without impeding replication or transmission resistance: reduce probability of infection, reduce replication, increase pathogen clearance.

Question 48

why arent hosts more resistant to diseases

Answer 48

-trade-offs between resistance and fitness related traits -pathogen evolution -tradeoff between resistance and weakness to other diseases

Question 49

host- parasite interactions ,may lead to

Answer 49

co evolutionary dynamics that increase genetic diversity of both host and parasite

Question 50

Devil facial tumor

Answer 50

tasmanian devils -non viral clonally transmissible cancer

Question 51

chronic wasting disease

Answer 51

-elk and deer -highly contagious -caused by a prion -fatal neurological disease

Question 52

Sylvatic plague

Answer 52

prairy dogs transmitted by fleas, endangered black footed ferrets also at risk

Question 53

whirling disease

Answer 53

caused by parasite causes young fish to die and older mfs to swim in tail chasing motion

Question 54

Chytridiomycosis

Answer 54

causing major decline in amphibians chytrid fungus responsible inhibits ability to breathe

Question 55

white nose syndrome (Pd)

Answer 55

-Ascomycete fungus -bats -attacks bare skin of hybernating bats -causes them to be more active than normal, burning fat -stores and making them leave in the winter -Huge decline in bats