viruses

Question 1

what does R0 have to be for an infection to die out?

Answer 1

<1

Question 2

what proportion of the population needs to be vaccinated to eliminate a virus

Answer 2

1-1/R0

Question 3

What are the 4 chronologic stages of host response? Give examples

Answer 3

physical barriers: skin, saliva, tears, stomach acid
Intrinsic: Interferons, autophagy, apoptosis
Innate: natural killer cells, complement, antigen-presenting cells
Adaptive: T and B cells

Question 4

what is R0

Answer 4

basic reproduction number

Question 5

what’s the deal with secondary response

Answer 5

BIGGER and faster

Question 6

what is hematogenous spread?

Answer 6

Entry of blood borne virus, spread to organs, spread back into blood and then shed

Question 7

what type of cell form the epithelium between mother;s blood supply and baby’s ECM

Answer 7

syncytiotrophoblasts

Question 8

name 3 trans-placental viruses

Answer 8

rubella, herpes simplex, zika

Question 9

what antimicribials do tears contain

Answer 9

lysozymes and antibodies IgA

Question 10

how do measles, mumps, rubella and varicella get into the body

Answer 10

olfactory neurons

Question 11

what are the 3 stages of PCR with temperatures

Answer 11

denaturation: 95
annealing: 68
elongation: 72

Question 12

how does HIV like to get into the body?

Answer 12

via the gut - lots of lymphatic and dendritic tissue - fast burst of viral replication

Question 13

what is the most common sort of viral infection

Answer 13

respiratory