Unit 2: Infection, Infectious Disease, Epidemiology

Question 1

Define Sign

Answer 1

Observable or measurable disease characteristics

Ex: Rash, coughing, vomiting, diarrhea, fever, swelling

Question 2

Define Symptom

Answer 2

Disease characteristic that can be felt only by pt, cant be quantitated

Ex: Pain, nausea, malaise, shortness of breath

Question 3

Define Syndrome

Answer 3

Combo of signs & symptoms that characterize a particular disease

Ex: toxic shock syndrome: fever, low blood pressure, red rash on trunk that peels

Question 4

Define Virulence

Answer 4

Degree of disease produce

Ex: rabies virus = causes neurological damage that is nearly always fatal

Bacillus cereus = causes only mild gastrointestinal upset

Question 5

Define Virulence factor

Answer 5

Help pathogens cause infection and disease

Question 6

Define Latrogenic

Answer 6

Type of nosocomial infection that results from modern medical procedures

Question 7

Endotoxin (aka lipopolysaccharide)

Answer 7

-Incorporated into the cell wall of Gram-Negative bacteria
-released when bacterium dies
-causes fever (pyrogenic) and decreased BP
“Endotoxic shock”

Question 8

Exotoxins

Answer 8

• Soluble solutions made by bacteria & secreted into host tissue

-made by gram positive & negative

Question 9

Endemic Disease

Answer 9

Occurs at a relatively stable frequency within a given area or population

Question 10

Sporadic disease

Answer 10

Occurs only in a few scattered cases in a given area or population

Question 11

Epidemic disease

Answer 11

Occurs at a greater than normal frequency within a given area or population

Ex: a local outbreak

Question 12

Pandemic disease

Answer 12

Occurrence of an epidemic more than one continent simultaneously

Ex: a worldwide outbreak (covid)

Question 13

Prevalence

Answer 13

of TOTAL cases of a disease in a given area during a given period of time

-the proportion of the population that has the disease

Question 14

Incidence

Answer 14

of NEW cases of a disease in a given area during a given time period

-the rate of occurrence of the disease

Question 15

Pathogenicity

Answer 15

Capacity to produce disease

mycobacterium tuberculosis= nearly always causes disease upon entering a susceptible host

Question 16

Parasitism

Answer 16

• parasite benefits ; host is harmed
• disease causing microbes or pathogens

Ex: tuberculosis bacteria in human lung

Question 17

Mutualism

Answer 17

*both members benefit *
Ex: escherichia coli live in human gut
1) e.coli help to make vitamin k used by human body
2) human gut provides nutrients to e.coli

Question 18

Resident microflora

Answer 18

Microorganisms that are always present on the human body in areas favorable to their growth
Ex: skin, conjunctiva, mouth, nose, throat, large intestine, urinary tract, reproductive tract

Question 19

Zoonotic diseases

Answer 19

Spread from animals to human

Ex: tapeworm= dogs - transmitted in dog saliva

Question 20

Human Reservoirs

Answer 20

• active disease & exhibit symptoms

Question 21

Carriers

Answer 21

Have no symptoms but infect others
-syphilis
-AIDs

Question 22

Non living Reservoirs

Answer 22

1. Soil
2. Water
3. Food

Question 23

Process of Infection

Answer 23

1) contamination
2) infection
3) disease

Question 24

Contamination

Answer 24

Microbes are present in host

Question 25

Infection

Answer 25

Microbes multiply within or upon hosts body

Question 26

Disease

Answer 26

Infection disrupts normal host function

Question 27

Coagulase

Answer 27

-bacterial enzyme that causes blood to clot

• helps to wall microbe off from immune system

Question 28

Streptokinase

Answer 28

-bacterial enzyme that dissolves blood clots

-helps to free microbe from clot so can spread to other tissue

Question 29

Incubation period

Answer 29

-time between infection & appearance of signs and symptoms

-response of host

-properties of pathogen
1)organisms 2)virulance 3)# that enter body 4) entry site relative to tissue affected

Question 30

Prodromal Phase

Answer 30

• prodome = forerunner
  -period where non specific symptoms (malaise) occur
  -infected individuals =contagious

Question 31

Illness Phase

Answer 31

• disease spreads thru body from entry site
  -typical signs & symptoms of disease appear
  -acme
  1) point where signs & symptoms most severe
  2) often associated w/ fever

Question 32

Decline Phase

Answer 32

• symptoms begin to subside
• host defense & medical tx overcome pathogen

Question 33

Covalenscence Period

Answer 33

-Recovery period
1) tissues repaired
2) healing takes place

Question 34

Sequelae

Answer 34

1) disease after effects
2) scarring to organ damage

Question 35

Contact transmission (3 modes)

Answer 35

Direct: person -to- person spread
Indirect: on inanimate objects (fomites)
Droplet: drops of mucus that exit body thru sneezing or coughing

Question 36

Vehicle transmission - Airborne

Answer 36

spread to respiratory tract
- mucus travel >1 meter
- aerosols from AC, sweeping,mopping, changing bed linens or clothes

Question 37

Vehicle transmission - waterborne

Answer 37

Spread to gi tract or skin

Question 38

Vehicle Transmission - Foodborne

Answer 38

Spread to gi tract

Question 39

Vehicle transmission - Bodily Fluid

Answer 39

• AIDs
• Hepatitis
• Herpes

Question 40

Vector Transmission

Answer 40

Transmission from one host to another by animal (vector)

Question 41

Biological Vector

Answer 41

• Transmits pathogen
• Infected by pathogen
• Anopheles mosquito transmits malaria

Question 42

Mechanical Vector

Answer 42

A carrier
- Transmits pathogen
- Not infected by pathogen
- FLIES transmit cholera

Question 43

Hyaluronidase & Collagenase

Answer 43

Allow bacteria to invade deeper tissue

Question 44

Host

Answer 44

Any organism that harbors another organism