Chapter 11

Question 1

What are the differences between bacteria that reside in our bodies and those that cause disease?

Answer 1

Only normal in one part of your body

Question 2

What is disease?

Answer 2

Any change from a general state of good health for an individual

Question 3

Infection refers to:

Answer 3

An imbalance between the host and microbe

Question 4

Mutualism

Answer 4

Both host and microbe benefit

Question 5

Commensalism

Answer 5

The microbe benefits and the host is unaffected

Question 6

What is a pathogen?

Answer 6

A microbe whose relationship with its host is parasitic and results in infection and disease

Question 7

How does disease occur?

Answer 7

1. An exogenous infection occurs if a pathogen enters sterile tissue
2. An endogenous infection occurs if normal microbiota enter
3. Primary infections occur in healthy bodies ex) flu
4. Secondary infections occur in a body weakened by a primary infection ex) pneumonia

Question 8

Portals of entry?

Answer 8

Mouth, GI, skin, urogenital

Question 9

Disease progression as a microbe?

Answer 9

1. Get in
2. Attach
3. Survive
4. Damage
5. Get out

Question 10

What is it called when a microbe establishes itself in a host and causes damage?

Answer 10

Virulence

Question 11

Disease progression in a human?

Answer 11

1. Incubation - entry of microbe
2. Prodromal - mild signs/symptoms
3. Acute period -signs and symptoms are most intense
4. Period of decline - signs and symptoms subside
5. Period of convalescence - body back to normal

Question 12

Acute diseases

Answer 12

Very short ex) flu

Question 13

Chronic disease

Answer 13

Linger for long periods of time and slower to develop ex) hepatitis

Question 14

What is invasiveness?

Answer 14

The ability of a pathogen to penetrate tissues and spread

Question 15

What is virulence factors?

Answer 15

Any characteristic or structure of the microbe contributes to its ability to establish itself in the host and cause damage

Question 16

Examples of virulence factors?

Answer 16

Streptokinase- dissolves fibrin clots and allows dissemination of the bacteria
Leukocidins-disintegrate neutrophils and macrophages (WBC)
Hemolysins-dissolves red blood cells
Biofilms- immune cells cannot reach bacterial cells covered in biofilm, protective structure

Question 17

Two types of toxins:

Answer 17

1. Exotoxins

2. Endotoxins

Question 18

Exotoxins

Answer 18

Proteins that are secreted

Question 19

Endotoxins

Answer 19

Released upon disintegration of bacteria

Question 20

Chemical composition differential characteristics between exotoxins and endotoxins?

Answer 20

Exo: small particles
Endo: lipopolysaccaride of well wall

Question 21

Denatured by heat differential characteristics of bacterial between exotoxins and endotoxins?

Answer 21

Exo: yes
Endo: no

Question 22

Typical sources differential characteristics of bacteria between exotoxins and endotoxins?

Answer 22

Exo: a few gram + and gram -
Endo: all gram negative bacteria

Question 23

Localized infection

Answer 23

Microbes enter the body, remain confined to a specific tissue

Ex) boils, warts, final skin infections

Question 24

Systemic infection

Answer 24

Infection spreads to several sites and tissue fluids, usually the blood

Ex) mumps, rubella, chickenpox, aids, anthrax, typhoid, syphilis

Question 25

Focal infection

Answer 25

Infectious agent spreads from a local site and is carried to other tissues Ex) TB, streptococcal pharyngitis

Question 26

Mixed infection

Answer 26

Several agents establish themselves simultaneously at the infection site Ex) human bite infections, wound infections

Question 27

Primary infection

Answer 27

The initial infection Ex) can be any infection

Question 28

Secondary infection

Answer 28

A second infection caused by a different microbe, which complicates a primary infection - often a result of lowered host immune defenses Ex) flu complicated by pneumonia, common cold complicated by bacterial otitis media

Question 29

Acute infection

Answer 29

Infection comes rapidly, with severe but short lived effects Ex) flu

Question 30

Chronic infection

Answer 30

Infection that progresses & persists over a long period of time Ex) HIV

Question 31

What is a sign?

Answer 31

Objective evidence of diseases as noted by an observer (what you can see) Ex) edema, granulomas and abscesses, lymphadenyitis

Question 32

What is a symptom?

Answer 32

Subjective evidence of disease as senses by the patient (what u feel) Ex) fever, pain, soreness, swelling

Question 33

What is a syndrome?

Answer 33

A disease identified by a certain complex of signs and symptoms

Question 34

What is a reservoir?

Answer 34

Where pathogens live - primary habitat in the natural world from which a pathogen originates - often a human or animal carrier - also soil, water, and plants

Question 35

What is a transmitter?

Answer 35

Individual or object from which an infection is acquired -syphilis: reservoir and transmitter are the same - hepatitis: reservoir is a human, transmitter is food

Question 36

Majority of animal reservoirs are....?

Answer 36

Arthropods - fleas, mosquitos, flies, ticks

Question 37

Biological vector:

Answer 37

Actively participates in a pathogens life cycle, serving as a site in which it can multiply or complete its life cycle

Question 38

Mechanical vector:

Answer 38

Carries the microbes more or less accidentally on its body parts Ex) hands and spreading it

Question 39

What's Zoonosis?

Answer 39

Transfer of microbes b/t animals & humans

Question 40

Transmission of infections:

Answer 40

Communicable, contagious, non communicable

Question 41

What's communicable?

Answer 41

A disease in which an infected host can transmit the infectious agent to another host and establish infection in that host

Question 42

Contagious:

Answer 42

A disease that is highly communicable, especially they direct contact

Question 43

Non-communicable

Answer 43

An infectious disease that does not arise thru transmission of the infectious agent from host to host

Question 44

Nosocomial infection:

Answer 44

Infection acquired during hospital stay -2-4 million cases a year resulting in 90,000 deaths

Question 45

Epidemiology

Answer 45

The study of disease in populations

Question 46

Prevalence:

Answer 46

the total number of existing cases with respect to the entire population

Question 47

Incidence:

Answer 47

Measures the number of new cases over a certain time period -also called the case or morbidity rate; indicates both the rate and risk of infection

Question 48

Endemic:

Answer 48

Disease is always present at a low level in a certain geographic area

Question 49

Epidemic:

Answer 49

Disease occurs in a region in excess of what is normally found in that population - not usually there

Question 50

Outbreak:

Answer 50

Is a more contained epidemic

Question 51

Pandemic:

Answer 51

Is a worldwide epidemic