Epidemiology of Infectious Diseases

Question 1

Differentiate between infection and infectious disease

Answer 1

Infection is the invasion of a host by a pathogen
Infectious disease is the illness as a result of the infection

Question 2

This term describes the ability of an agent to infect and multiply —> disease

Answer 2

Pathogenicity

Question 3

This is the pathophysiological reaction of the host to the infection

Answer 3

Severity

Question 4

Can a person be a case and a contact at the same time?

Answer 4

No
A contact is someone who has been exposed but hasn’t been confirmed to have the infectious disease. They must quarantine until they are confirmed to have the disease

A case is someone who is confirmed to have an infectious disease

Question 5

This is the time between exposure and the appearance of S&S

Answer 5

Incubation period

Question 6

During what time is a person able to transmit a disease?

Answer 6

The infectious period/period of communicability

Question 7

Is it necessary for a person to have S&S to be in the infectious period?

Answer 7

No
People are able to transmit a disease even when they aren’t showing any S&S

Question 8

Malaria is endemic to tropical and subtropical regions, particularly those with the anopheles mosquito. What kind of occurrence does malaria demonstrate?

Answer 8

Endemic
Occurs constantly at a maintained rate within a region — continuous high prevalence

Question 9

What is the term for a disease demonstrating temporarily high prevalence in a population over a specific time?

Answer 9

Epidemic

Question 10

This is the spread of an epidemic to global proportions

Answer 10

Pandemic

Question 11

What are the 3 components of the epidemiological triangle?

Answer 11

Agent
Host
Environment

Question 12

What part of the epidemiological triangle do pathogens fall into?

Answer 12

Agent: the thing causing the infectious disease

Question 13

What host factors impact susceptibility of a host to an agent?

Answer 13

Genetics
Age
Health status
Living conditions

Question 14

What is herd immunity?

Answer 14

Resistance of a population to a particular disease

Question 15

What determines the herd immunity a population has to a disease?

Answer 15

The amount of pre-existing immunity in a high proportion of ppl r/t previous infection or vaccination

Question 16

What is a factor that determines the amount of immunity needed in a group of ppl to gain herd immunity?

Answer 16

The pathogen

Question 17

What are the 2 requirements for herd immunity?

Answer 17

High and variable immunity within a group
Uniform distribution of immunity within a group

Question 18

What environmental factors can make a host susceptible to an infectious disease?

Answer 18

living conditions
Water/food
Climate
Pollution
Migration

Question 19

What are the 6 components of the chain of infection?

Answer 19

Agent
Reservoir
Portals of exit
Mode of transmission
Portals of entry
Host

Question 20

A term used for the habitat in which an infectious agent normally thrives and multiplies

Answer 20

Reservoir

Question 21

What are the direct modes of transmission?

Answer 21

Direct transmission is the immediate transfer to a portal of entry
Ex droplet, touching, biting, kissing, etc.

Question 22

What are indirect modes of transmission?

Answer 22

An intermediate is contaminated, interacted with by the host and then leads to infection of the host
airborne
Waterborne
Food borne
Vector borne (carried by another living thing)
Fomites (inanimate materials/objects)