Disease Reservoir and Pathogen Transmission

Question 1

Chain of transmission

Answer 1

Infectious Agent
Reservoir
Portal of exit
Mode of transmission
Portal of entry
Susceptible host

Question 2

Chain of Infection

Answer 2

Reservoir
Agent
Mode of transmission
Susceptible host (portal of entry, portal of exit)
Transmission

Question 3

Exposure

Answer 3

Introduction of a new pathogen into a susceptible population

Question 4

Transmission

Answer 4

Adoption, establishment, and dissemination in the susceptible population. Requires a pathogen that can adapt to, and transmit between, these hosts

Question 5

Reservoir

Answer 5

Habitat or populations in which an infectious agent normally lives, grows and multiplies
Maintain pathogens over time
Different strategies to survive in the reservoir

Question 6

Animal Reservoir. Remember:

Answer 6

Reservoir does not mean ill
An individual can be killed by the agent but the population maintains the agent
If asymptomatic: then we consider carrier
Not all sick animals are reservoirs

Question 7

Exposure and Transmission

Answer 7

Reservoir population
Exposure
Susceptible population
Transmission
Disease epidemic

Question 8

Reservoir Examples
Measles
Feline Leukemia
Rabies
Leptosspirosis

Answer 8

Humans
Cats
Multiple
Rodents

Question 9

Portal of exit

Answer 9

The method the pathogen uses to leave the body of the host

Question 10

Portal of exit examples

Answer 10

Saliva
Blood
Feces
Urine
Vaginal secretion

Question 11

Vertical Tranmission

Answer 11

Infection at fecundation and transplacental

Question 12

Infection at fecundation

Answer 12

virus can attach to spermatozoa or oocyte

Question 13

Transplacental

Answer 13

Infection in utero

Question 14

Vertical transmission: transmission to eggs

Answer 14

Transmission of the pathogen agent during the egg development
Salmonella enterica Serovar pullorum
Mycoplasma

Question 15

Vertical transmission: perinatal

Answer 15

At parturition (HIV)
Through the colostrum/milk

Question 16

Vertical Transmission: transovarial

Answer 16

Passage of pathogen from the adult female to eggs through the ovaries of an arthropod

Question 17

Transstadial Transmission

Answer 17

Another transmission in arthropods is called transstadial transmission

Question 18

Horizontal transmission: Direct

Answer 18

Directly from the reservoir to a susceptible host
limited space
Without intermediary
short time period

Question 19

Horizontal transmission: Indirect

Answer 19

via any sort of intermediary, animate, or inanimate
Distance
intermediary
longer time period

Question 20

Direct by contact

Answer 20

skin and mucous membrane

Question 21

Direct by air

Answer 21

Direct projection (droplet spread): wet, large, and short range aerosoles
Airborne: considered to be a form of direct transmission because disease agents do not generally survive for extended periods within aerosolized particles
Waterborne (for aquatic animals only): through gills

Question 22

Indirect: Vehicle

Answer 22

An inanimate object which serves to communicate disease
Water, food, soil
Fomite: object that can be contaminated and transmit disease on a limited scale

Question 23

Indirect: vector

Answer 23

Arthropods who carry and transmit pathogens

Question 24

Mechanical Vector

Answer 24

An animal that carries a pathogen from one host to another without being infected itself

Question 25

Biological vector

Answer 25

The pathogen undergoes changes or multiplies while in the vector

Question 26

Portal of Entry

Answer 26

The method the pathogen uses to enter the body of the susceptible person or animal
Most of the pathogens can not go through an intact skin
Animal body has a lot of projection

Question 27

Susceptible host

Answer 27

Epidemiological definition: member of a popular who is at risk of becoming infected by a disease