Tranmission Of Disease

Question 0

Which part of the triad is the primary cause of disease, without it disease cannot occur?

Answer 0

Agents

Question 1

What are three parts of epidemiologic triad?

Answer 1

Environment, host, agent

Question 2

What is an example of a common nutritive agent?

Answer 2

Metazoa, Protozoa, bacteria, fungi, rickettsia, viruses

Question 3

Give an example of a genetic factor

Answer 3

Age, gender, immunity

Question 4

Give an example of endogenous chemical agent

Answer 4

Protein deficiency, vitamin deficiency, pollutants

Question 5

What is the difference between metazoan and protozoan agents?

Answer 5

Metazoan are multicellular

Protozoan are single called

Question 6

Give examples of bacterial, viral, fungal, rickettsial agents

Answer 6

Bacteria- pneumonia
Viral - small pox
Fungal - coccidiodes immitis
Rickettsia - ticks

Question 7

Stress or fatigue is which part of epidemiologic triad?

Answer 7

Environmental

Question 8

What is the difference between passive and active immunity? Give example.

Answer 8

Passive- borrowed from another host (breast feeding)

Active- agent indused (vaccination)

Question 9

What is the difference between IgM and IgG immunoglobulins with respect to infectious state?

Answer 9

IgM- first type of antibody made in response to an infection, contact IgG
IgG-important in fighting bacterial and viral infections

Question 10

The density of the population is largest in urban areas, what kind of factor is this?

Answer 10

Environmental

Question 11

What are the three modes of disease transmission?

Answer 11

Direct - touch
Airborne - 10ft radius
Indirect - doorknob

Question 12

Eating eggs with salmonella is a form of what mode of transmission?

Answer 12

Direct

Question 13

What is the difference between direct and airborne transmission?

Answer 13

Direct is touch or veins, while airborne you do not need to directly be touching it but can be 10ft away from it and get it

Question 14

What is the difference between direct and indirect transmission?

Answer 14

Direct you must be touching it or blood touching and indirect can be passed by doorknob or handshake, or by a flea/tick

Question 15

Name a disease that is transmitted by Arthropods, what kind of transmission is this?

Answer 15

Bubonic plague via rat fleas

Indirect transmission

Question 16

What are fomites?

Answer 16

an inanimate object (as a dish, toy, book, doorknob, or clothing) that may be contaminated with infectious organisms and serve in their transmission

Question 17

Give an example of disease whose human portal of entry is through the skin

Answer 17

Rabies, bubonic plague, anything that can enter bc of broken skin

Question 18

Give an example of a disease whose human portal entry is through the mouth/stomach

Answer 18

Salmonella by eating food or water that’s contaminated

Question 19

What is a reservoir of infection?

Answer 19

Humans
Animals
Environmental or free living organisms

Question 20

What is a reservoir for rabies?

Answer 20

Animals

Question 21

What is a reservoir for athletes foot?

Answer 21

Environment

Question 22

Infectivity

Answer 22

The ability of a pathogen to spread from one host to another

Question 23

Pathogenicity

Answer 23

Ability of agent to infect its host like clinical symptoms

Question 24

Virulence

Answer 24

Ability of an agent to produce severe disease

Question 25

Infectivity formula

Answer 25

``` # of ppl infected ------------------- # of ppl exposed ```

Question 26

Pathogenicity formula

Answer 26

``` # of ppl w/disease --------------------- # of ppl infected ```

Question 27

Virulence formula

Answer 27

``` # of ppl w/severe disease ------------------------------ # of ppl w/clinical disease ```

Question 28

Does rabies have high or low Infectivity, pathogenicity, virulence? How do you know?

Answer 28

Low, high, high Bc rabies is contracted by a bite from an animal that has it so it cannot infect that many ppl, but it is about to infect the host, and it is able to produce a severe disease

Question 29

Does measles have low or high Infectivity, pathogenicity, virulence? How do you know?

Answer 29

High, high, intermediate | Bc you can infect others easily, and able to infect the host quick, and if not treated it can cause a severe disease

Question 30

With what measure can we calculate virulence of a disease?

Answer 30

Case fatality rate

Question 31

Epidemic

Answer 31

Occurrence of disease is higher than baseline (what we normally expect)

Question 32

Pandemic

Answer 32

Excess # of cases in many countries at same time

Question 33

Endemic

Answer 33

Continuous presence of a disease w/in a certain geographic area

Question 34

What defines an epidemic?

Answer 34

rapid spread of infectious disease to a large number of people in a given population within a short period of time, usually two weeks or less

Question 35

What does eradication mean? Example

Answer 35

Eliminate or destroy | Small pox

Question 36

What is another word for an outbreak?

Answer 36

Epidemic

Question 37

What is an incubation period?

Answer 37

Time btwn contact w/agent & on set of symptoms

Question 38

Case fatality rate formula

Answer 38

``` # dead --------- # infected ```

Question 39

What is the communicable period?

Answer 39

Institution of control measures such as isolation and quarantine

Question 40

What are two control measures that we can use when dealing with ppl during the communicable period of their disease?

Answer 40

Isolation and quarantine

Question 41

Herd immunity

Answer 41

occurs when the vaccination of a significant portion of a population provides a measure of protection for individuals who have not developed immunity

Question 42

What is the magic number to determine herd immunity of a disease? What does it depend on?

Answer 42

95% | It depends on the disease and location

Question 43

What is the level of vaccination that must be reached for herd immunity to occur in the case of measles?

Answer 43

90-95% must be vaccinated

Question 44

Attack rate formula

Answer 44

of ppl develop disease ------------------------------ Total # of ppl at risk -vaccinated or already had disease pop. Don't count

Question 45

What is a secondary attack rate?

Answer 45

Probability that infection occurs among susceptible persons within a reasonable incubation period following known contact with an infectious person or source