7. Disease causes, determinants, transmission

Question 1

epidemiological triad

Answer 1

agent, host, environment

Question 2

3 factors that influence disease potential

Answer 2

agent, host, and environment

Question 3

agent factors

Answer 3

infectivity
pathogenicity
virulence
immunogenicity
antigenic stability
survival

Question 4

infectivity

Answer 4

a measure of the ability of a disease agent to establish itself in the host

referred to qualitatively low medium high

Question 5

pathogenicity

Answer 5

an epidemiological term used to describe the ability of particular disease agents of known virulence to produce disease in a range of hosts under a range of environmental conditions

Question 6

virulence

Answer 6

a measure of severity of a disease caused by a specified agent

Question 7

host factors

Answer 7

species
breed
sex
age
confirmation
genotype
nutrition status
physiologic status
pathologic status

Question 8

sex factors of host example

Answer 8

hemophilia A = most common inherited bleeding disorder in dogs

females carry the gene

Question 9

age factors of host example

Answer 9

arthritis in cats

Question 10

environment factors

Answer 10

weather
housing
geography
management practises
noise
water
air
food
chemicals

Question 11

Kochs postulates for infection diseases

Answer 11

1. the agent should be present infall cases of the disease
2. it can be isolated and grown in pure culture
3. it should be capable of producing the disease when into healthy animals
4. the same organism should be recovered from the diseased animal

Question 12

limitation of kochs postulates

Answer 12

do not apply for inapparent infections or carrier states

some organisms are tough to grow in pure culture

rarely apply to viral infections/diseases

do not apply to multifactorial etiologies

Question 13

modes of transmission

Answer 13

direct and indirect contact

Question 14

direct transmission contact

Answer 14

direct contact transmission is the physical contact between an infected individual and a susceptible individual and the physical transfer of microorganisms

touching

Question 15

airborne diseases

Answer 15

caused by pathogens and transmitted through air

Question 16

droplet contact transmission

Answer 16

considered direct transmission which is primarily respiratory

Question 17

indirect transmission

Answer 17

referred to situation where a susceptible person is infected from contact with a contaminated surface or material

Question 17

indirect transmission

Answer 17

referred to situation where a susceptible person is infected from contact with a contaminated surface or material

Question 18

fomite

Answer 18

any object or substance capable of carrying infectious organisms such as germs or parasites

Question 19

food borne indirect transmission

Answer 19

a disease caused by consuming contaminated food and drink

Question 20

vector borne indirect transmission

Answer 20

transmission via insect or animal vectors

Question 21

horizontal and vertical transmission

Answer 21

horizontal = same species

vertical = to offspring

Question 22

zoonosis

Answer 22

is any disease or infection that is naturally transmissible between vertebrate animals and humans

Question 23

zoonotic disease

Answer 23

is a disease that can be passed between animals and human