Ch 14 Principles of Disease and Epidemiology

Question 1

define symbiosis

Answer 1

2 or more organisms living in close association w each other

Question 2

define commensalism symbiosis

give an example

Answer 2

one organism benefits, the other is uneffected

ex:staph epidermis on skin; we provide home/nutrients, no benefit

Question 3

define mutualism symbiosis

give example

Answer 3

2 organisms both benefit

ex: E coli in large intestine; we provide food/warmth/home, helps us breakdown vitamin K for blood clotting

Question 4

define parasitism symbiosis

give example

Answer 4

one benefits, the other doesnt

ex: H1N1 virus

Question 5

when is our microbiota first established, how?

Answer 5

at birth, lactobacilli in birth canal increases in abundance right before birth

Question 6

define the normal microbiota

Answer 6

microorganisms that establish permanent residence but do not produce disease under normal conditions

Question 7

how microbiota prevents disease

Answer 7

prevents overgrowth of harmful microorganisms by competing for nutrients (competitive exclusion), producing substances harmful to invaders, and affecting conditions such as pH and O2 availability

Question 8

steps in Koch’s postulates

Answer 8

1. microorganisms isolated from diseases/dead animal
2. grown in pure culture, IDed via microscope
3. injected into healthy animal
4. disease reproduced
5. microbes isolated from this animal, IDed

Question 9

why was Koch’s postulates useful

Answer 9

helped understand the relationship between pathogens and disease. helped determine the etiology of disease

Question 10

limitations of Koch’s postulates

Answer 10

1. some organisms hard to culture
2. some have very narrow range (only infect humans-> inhumane)
3. same organism can cause different diseases(shingles and chicken pox)
4. one disease caused by many diff organisms (pneumonia)

Question 11

difference between signs and symptoms

Answer 11

signs- objective, measurable

symptoms-subjective, self-reported

Question 12

define a syndrome

Answer 12

recurrence of v similar set of signs+symptoms (may always occur w particular disease)

Question 13

is swelling a sign or symptom

Answer 13

sign

Question 14

is wheezing a sign or symptom

Answer 14

sign

Question 15

list stages of disease in order

Answer 15

1. incubation period
2. prodromal period
3. period of illness
4. period of decline
5. period of convalescence

Question 16

the incubation period is also known as the____ period

what is happening?

Answer 16

eclipse; no signs or symptoms, pathogen entering cells

Question 17

disease stage when mild signs/symptoms occur

Answer 17

2. prodromal period

Question 18

disease stage w most signs/symptoms

Answer 18

3. period of illness

Question 19

when during disease stage does the number of microbes peak

Answer 19

end of 3.period of illness

Question 20

what are nosocomial infections

Answer 20

hospital acquired infections

Question 21

3 factors that lead to nosocomial infection

Answer 21

microbes in hospital, compromised host (ex:surgery), chain of transmission (connection between host and organism )

Question 22

what is the CDC

Answer 22

centers for disease control and prevention

Question 23

the CDC monitors EID’s which are

Answer 23

emerging infectious diseases

Question 24

which branch of epidemiology did John snow develop, how?

Answer 24

descriptive epidemiology-observed occurence of cholera outbreak, mapped where affected residents were compared to where they got their well water

Question 25

what is descriptive epidemiology

Answer 25

looking at different correlations (john snow and cholera)

Question 26

which branch of epidemiology did Ignaz Semmelweis develop, how?

Answer 26

experimental epidemiology- required med students to wash hands before disinfecting cadavers and delivering babies, decreased maternal mortality ratedue to puerpurel fever

Question 27

what is experimental epidemiology

Answer 27

identifying a variable, changes conditions, noting results (Semmelweis and maternal puerpurel fever deaths)

Question 28

which branch of epidemiology did Florence Nightingale develop, how?

Answer 28

Analytical epidemiology- recognized difference in Typhus mortality in different armies and their sanitary conditions. graphed this data