Infection, Infectious Disease, and Epidemiology

Question 1

Define pathology

Answer 1

Pathology is the study of the causes and effects of disease or injury.

Question 2

Define etiology

Answer 2

study of the cause of disease

Question 3

Define infection

Answer 3

an invasion of the body by an infectious microorganism or virus

Question 4

Define disease

Answer 4

a condition where health is affected

Question 5

Define normal microbiota

Answer 5

Acquired from our environment, colonize the skin and large intestine.

Question 6

define microbial antagonism

Answer 6

good bacteria outcompete bad bacteria

Question 7

define mutualism

Answer 7

both organisms benefit

Question 8

define commensalism

Answer 8

one organism benefits and the other is neutral

Question 9

define parasitism

Answer 9

one organism benefits and other is harmed

Question 10

How does an infection become oppurtunistic?

Answer 10

normal microbiota that moves to a new area and becomes pathogenic or on an immunocompromised host

Question 11

Examples of portal of entry

Answer 11

mucous membranes, parenteral (nonintact skin, puncture), inhalation or ingestion, through skin (hair follicle, sweat gland), and placenta (congenital).

Question 12

define signs vs symptoms

Answer 12

symptoms: subjective changes felt by a patient (headache, pain, dizziness)
signs: objective changes that acn be observed or measured (temp, BP, labs)

Question 13

define epidimieology

Answer 13

study of when and where diseases occur and how they are transmitted

Question 14

define endemic

Answer 14

always present

Question 15

define epidemic

Answer 15

large # of people affected in a short period of time in one area

Question 16

define pandemic

Answer 16

epidemic occurring on one or more continents

Question 17

define mortality

Answer 17

number of individuals killed by a disease

Question 18

define morbidity

Answer 18

Number of individuals affected by a disease

Question 19

define incubation period

Answer 19

time between the entrance of the infectious agent and the onset of illness

Question 20

define latent period

Answer 20

period of time when an infectious agent is not causing signs and symptoms but can show up later

Question 21

list the exceptions of koch’s postulates

Answer 21

-can’t always grow in pure culture
-the same agent can cause different diseases
-some people are immune/carriers and won’t get the disease
-not always possible to inoculate the same animal
-different strains with different virulence factors are possible

Question 22

describe virulence

Answer 22

how pathogenic an infectious agent is, how transmissible or how easily it causes disease

Question 23

Describe the relationship between adhesins/ligands and receptors on the surface of the host cell.

Answer 23

adhesions/ligands bind to receptors on the surface of the cell and help the pathogen stick to the cell. Receptors and ligands must match.

Question 24

What is the target of leukocidins?

Answer 24

break down WBC

Question 25

What is the target of hemolysins?

Answer 25

break down RBC

Question 26

What is the target of coagulases?

Answer 26

convert fibrinogen to fibrin, and cause blood clots

Question 27

What is the target of kinases?

Answer 27

anticlotting

Question 28

What is the target of hyaluronidase?

Answer 28

breaks down hyaluronic acid in connective tissue

Question 29

What is the target of collagenese?

Answer 29

breaks down collagen in connective tissue

Question 30

How do invasions affect the host cell?

Answer 30

rearrange the cytoskeleton of the host cell and converts it into a shield for itself

Question 31

Examples of exotoxin infections

Answer 31

gangrene, tetanus, botulism, diptheria, scarlet fever

Question 32

Examples of endotoxin infections

Answer 32

typhoid fever, UTI, and mengi meningitis

Question 33

Which produces a fever, exo or endo toxins?

Answer 33

endo

Question 34

Which is more toxic, exo or endo toxin?

Answer 34

exo

Question 35

Describe some antiphagocytic factors that exist

Answer 35

-capsule -M protein (strep pyrogenes) - invasins

Question 36

prodromal period

Answer 36

not all diseases have this, illness has not started yet but host does not feel normal, mild symptoms

Question 37

illness

Answer 37

full blow signs and symptoms

Question 38

decline

Answer 38

severity of symptoms lessen

Question 39

convalescence

Answer 39

patient recovering

Question 40

acute vs chronic disease

Answer 40

acute: symptoms come on fast and last a short time chronic: symptoms are slow to develop and last longer

Question 41

reservoir of infection and examples

Answer 41

a living or non-living habitat that can harbor an infectious agent until a new host is encountered human reservoirs- host with signs and symptoms healthy chronic carrier asymptomatic carrier (incubation/latent) non human reservoirs- animals, soil, water

Question 42

Types of contact transmission direct, indirect, and droplet

Answer 42

direct: person to person, skin to skin indirect: transmission via fomite droplet: aerosol produced by coughing, and sneezing, travels less than 1 m.

Question 43

Describe vehicle transmission via food, water and air.

Answer 43

Something containing infectious agent that is ingested or inhaled water food air

Question 44

Describe vector transmission, distinguish between mechanical and biological vectors.

Answer 44

mechanical is passively transportation on body biological has the agent in the body and spreads through bite

Question 45

Distinguish between communicable and noncommunicable disease.

Answer 45

communicable- can be spread from host to host noncommunicable- not spread from person to person. can live outside host for a long time or is caused by normal microbiota (acne/tooth decay)

Question 46

How are healthcare-associated (nosocomial) infections acquired?

Answer 46

from interaction with hospital fomites and from staff-patient interaction

Question 47

Why are healthcare-associated (nosocomial) infections acquired?

Answer 47

patients are often immunocompromised and have broken skin

Question 48

differences between exogenous and endogenous infections in nosocomial

Answer 48

exogenous-directly from environment of hospital endogenous- result of normal microbiota becoming pathogenic due to medical procedures

Question 49

How can nosocomial infections be controlled?

Answer 49

infection control committees, wash hands, change gloves, no ties

Question 50

what are iatrogenic infections in nosocomial infections?

Answer 50

physician induced

Question 51

How would you describe transient microbes?

Answer 51

microorganisms that are only temporarily found in the human body, and these may include pathogenic microorganisms

Question 52

How would you define a fomite?

Answer 52

inanimate object that that can spread disease

Question 53

What is the most common procedural cause of nosocomial infections?

Answer 53

catherterization

Question 54

name some locations where we lack normal microbiota.

Answer 54

blood, lower respiratory system, and CSF

Question 55

define amensalism

Answer 55

one organism is harmed the other is neutral