Exam 1 Viruses

Question 0

Lytic virus results in

Answer 0

lysis and death of cell,

dangerous regardless of how it replicates

Question 1

Viruses have NO independent metabolism

Answer 1

reproduce in a living cell only

Filteralbe agents - passage through pores is possible, very small.

Question 2

Progeny

Answer 2

what is it?

Question 3

Non lytic interaction with host of some viruses - virus remains in the host but genes are not expressed: PROPHAGE or PROVIRUS

Answer 3

ok

Question 4

PERSISTENT infections

Answer 4

infection without cell death; virus in long term ass with host

Question 5

Latent infections: herpes

Answer 5

Intermittent acute episodes between which almost total absence of virus particles and very limited viral synthesis: Herpes Simplex

Question 6

Chronic infection: Hep B virus

Answer 6

NOnLytic production of virus, continued presense of substantial # of viral particles during periods in which clin dz is ABSENT. Have particles but no dz. Hep B virus

Question 7

Transforming infections: HPV (cancer)

Answer 7

“infected host cells are turned to cancer cells: HPV

Question 8

Viral Gastoenteritis (inf of stomach and int) sx

Answer 8

ACUTE H2O D (main), nausea, vomit, cramps, maliase, anorexia, myalgia, HA (no fever)

Question 9

Clin pres of viral gastroenteritis

Answer 9

• replicates in SI epith cells
• short - lasts 3-5 days
• 15-48 hr incubation
• virus may shed for days to weeks after better

Question 10

Dx by

Answer 10

enzyme immunoessay or latex agglutination screen test

Tx; supportive, fluids, sugar and el, no ABx

Question 11

Epidem:

Answer 11

1) Infant D: ROTAvirus, enteric adenovirus
2) Outbreaks: Fecally cont food (NOROvisuses - NORwalk, SRSV): raw shellfish
Low dose path , now P to P

Question 12

ROTAteq and ROTArix - vaccines for ROTAvirus

but not NOROvirus

Answer 12

ok

Question 13

ROTOvirusses

Answer 13

-severe D of infants, 5-7 days of fever and vomit
- inf of SI villi enterocytes, disrupt OSMOTIC fx
“winter vomiting dz”

Question 14

ROTAshield - withdrawn from market due to intussusception

Answer 14

diff to tx without vaccine

Question 15

Enteric Adenoviruses

Answer 15

Double-stranded DNA
D of infants
Extended period 5-12 days: D, fever and vomit
Dx: immunoessay detection

Question 16

the Caliciviruses

Answer 16

NOROviruses are Norwalk and SRSV
Epidemics of D and vomiting, mild and self-limiting: 12-24 hr, older kids and adults, SHELLFISH (oysters), hard to inactivate

Question 17

NOROviruses spread

Answer 17

P to P
Shellfish first (oyster bar), then p to p
H2O borne
2nd leading cause of GI inf death (what is the first?)