lecture 35 - cellular basis of infectious disease

Question 1

What are the 5 stages of infectious disease?

Answer 1

Incubation period, prodromal period, illness, decline, convalescence

Question 2

What occurs in the ‘incubation period’ stage of an infectious disease?

Answer 2

Pathogen begins to inhabit host, but there are no signs or symptoms

Question 3

What occurs in the ‘prodromal period’ stage of an infectious disease?

Answer 3

Vague, general symptoms

Question 4

What occurs in the ‘illness’ stage of an infectious disease?

Answer 4

Most severe signs/symptoms - maximum number of microorganisms in the host.

Question 5

What occurs in the ‘decline’ stage of an infectious disease?

Answer 5

Declining signs/symptoms and decline number of microorganisms infecting

Question 6

What occurs in the ‘convalescence’ stage of an infectious disease?

Answer 6

No signs/symptoms, very few microorganisms remain

Question 7

What virus causes the common cold?

Answer 7

Rhinovirus

Question 8

What are the structural characteristics of a rhinovirus?

Answer 8

ssRNA, no envelope

Question 9

What are the 6 components of the the chain of infection?

Answer 9

Causative agent, reservoir/source, means of exit, mode of transmission, portal of entry, person at risk.

Question 10

What are examples of causative agents in terms of the chain of infection?

Answer 10

Viruses, bacteria, parasites

Question 11

What are examples of reservoirs/sources in terms of the chain of infection?

Answer 11

Humans, animals, fomites, food, water

Question 12

What are examples of means of exit in terms of the chain of infection?

Answer 12

Excretions, secretions, droplets

Question 13

What are examples of modes of transmission in terms of the chain of infection?

Answer 13

Contact, airborne, vectors

Question 14

What are examples of portals of entry in terms of the chain of infection?

Answer 14

Respiratory, gastrointestinal tracts, genitourinary tracts, mucous, skin

Question 15

What are examples of people at risk in terms of the chain of infection?

Answer 15

Young, elderly, immunocompromised.

Question 16

How can the chain of infection be broken at the causative agent stage?

Answer 16

Rapid detection and treatment

Question 17

How can the chain of infection be broken at the reservoir/source stage?

Answer 17

Good hygiene, sterilisation, disinfection

Question 18

How can the chain of infection be broken at the means of exit stage?

Answer 18

Waste removal, disinfection

Question 19

How can the chain of infection be broken at the mode of transmission stage?

Answer 19

Airflow control, bed spacing

Question 20

How can the chain of infection be broken at the portal of entry stage?

Answer 20

Aseptic technique

Question 21

Define mortality, in terms of an infectious disease

Answer 21

Incidence of death in a population

Question 22

Define morbidity

Answer 22

Incidence of disease, including fatal and non-fatal cases

Question 23

Define incidence

Answer 23

The number of new cases of a disease in a given time period

Question 24

Define prevalence, in terms of epidemiology

Answer 24

Total number of new and existing cases of a disease in a population at a give time

Question 25

Define endemic, in terms of disease

Answer 25

Amount of disease usually present in a community - ‘baseline’

Question 26

Define sporadic, in terms of disease

Answer 26

A disease that occurs infrequently and irregularly

Question 27

Define epidemic

Answer 27

A sudden increase in cases of a disease across a broad geographical area.

Question 28

Define pandemic

Answer 28

An epidemic that spans several countries or continents