Lecture 1: Pathogens in Perspective

Question 1

What are pathogens?

Answer 1

Biological agents that cause disease

Question 2

What are environmental pathogens?

Answer 2

Microorganisms that normally spend a substantial part of their lifecycle outside human hosts

Question 3

Name 4 types of protozoans

Answer 3

Amoebae
Ciliates
Flagellates
Apicomplexaans

Question 4

Where in the body has the nighest level of bacteria?

Answer 4

The large intestine

Question 5

What is microbial antagonism?

Answer 5

bacteria flora benefit by preventing overgrowth of harmful microbes

Question 6

In newborns, the initial gut bacteria depend on what?

Answer 6

The delivery mode

Question 7

What is a true pathogen?

Answer 7

Capable of causing disease in healthy persons with normal immune defences

Question 8

What is an opportunistic pathogen?

Answer 8

Cause disease when the hosts defences are compromised

Question 9

Severity of a disease depends on the what of a pathogen?

Answer 9

Virulence

Question 10

What are the 5 modes of transmission?

Answer 10

Person to person 
Waterbourne 
Foodborne 
Airborne 
Vector-borne

Question 11

What is an infectious dose?

Answer 11

The minimum number of microbes required for infection to proceed

Question 12

Microbes with a small infectious dose have a greater what?

Answer 12

Virulence

Question 13

What do features do microbes that to allow them to attach to the host?

Answer 13

Fimbrias
Flagella
Adhesion slime or capsules
Pili

Question 14

List three types of virulence factors

Answer 14

Exoenzymes
Toxigenicity
Antiphagocytic factors

Question 15

What are the 4 distinct phases of clinical infections?

Answer 15

Incubation period
Prodromal stage
Period of invasion
Convalescent period

Question 16

What is the incubation period?

Answer 16

Time from initial contact with the infectious appearance to the appearance of first symptoms

Question 17

What is the prodromal stage?

Answer 17

Vague feelings of discomfort, non specific

Question 18

What is the period of invasion?

Answer 18

Specific signs and stages and becomes well established

Question 19

What is a localised infection?

Answer 19

Microbes enters body and remains confined to a specific tissue

Question 20

What is a systemic infection?

Answer 20

Infection spreads to several sites and tissue fluids usually in the bloodstream

Question 21

What is a focal infection?

Answer 21

When infectious agent breaks loose from a local infection and is carried to other tissues

Question 22

What is an acute infection?

Answer 22

Comes on rapidly with severe but short lived effects

Question 23

What is a chronic infection?

Answer 23

Progress and persist over a long period of time

Question 24

What is a reservoir?

Answer 24

Primary habitat of pathogens in the natural world

Question 25

What is a source?

Answer 25

Individual or object from which an infection is actually acquired

Question 26

A live animal (other than human) that transmits an infectious agent from one host to another is called a what?

Answer 26

Vector

Question 27

What is prevalence?

Answer 27

Total number of existing cases with respect to the entire population

Question 28

What is incidence?

Answer 28

Measures of the number fo new cases over a certain time period, compared with general healthy population

Question 29

What is mortality rate?

Answer 29

The total number of deaths in a population due to a certain disease

Question 30

What is morbidity rate?

Answer 30

Number of people affected with a certain disease

Question 31

What is an endemic?

Answer 31

Disease that exhibits a relatively steady frequency over a long period of time in a particular geographic locale

Question 32

What does an epidemic occur?

Answer 32

When prevalence of a disease is increasing beyond what is expected

Question 33

When does a pandemic occur?

Answer 33

When an epidemic spreads across continents