W06_02 Herpesviridae virology

Question 1

what is tegument?

Answer 1

between envelope and capsid of a virus; like the cytoplasm of cells

Question 2

which of the 8 herpesviridae are airborne?

Answer 2

only VZV

Question 3

why don’t herpesviridae transfer via fomites readily?

Answer 3

survival in environment is unlikely due to envelope destruction

Question 4

note 4 out of 5 people with genital herpes hasn’t been diagnosed

Answer 4

3/5 have symptoms that are unrecognized as herpes!

Question 5

what percentage of primary herpes infections are symptomatic?

Answer 5

10-15%

Question 6

hsv-1 mostly affects where?

Answer 6

lips

Question 7

hsv-2 mostly affects where?

Answer 7

genitals

Question 8

corneal keratitis is caused by which herpes?

Answer 8

hsv-1

Question 9

note: hsv-2 is more persistent and more highly recurrent than hsv-1

Answer 9

okay

Question 10

is there an IgM test for herpes?

Answer 10

no

Question 11

how can you distinguish herpes primary infection from recurrence?

Answer 11

you can’t

Question 12

what drugs can you take for herpes?

Answer 12

acyclovir, famciclovir, valacyclovir;

note these have to be taken within 3 hours of initial herpes attack

Question 13

when’s the infectious period of VZV?

Answer 13

2 days BEFORE symptoms to full crusting

Question 14

what is the longterm consequence of VZV?

Answer 14

it lies latent in the nerve root ganglia (DRG); can come out as shingles with 30% chance

Question 15

how does shingles/zoster present?

Answer 15

it’s latent in the DRG, so will have dermatomal distribution

Question 16

effects of congenital vzv infection?

Answer 16

CNS retardation, muscular atrophy, limb hypoplasia

Question 17

where does shingles present the most?

Answer 17

on the chest

Question 18

how to diagnose vzv?

Answer 18

can use IgM for acute, IgG for immune status;
EM or immunofluorescence;
isolation - vesicular fluid

Question 19

how to prevent vzv post-exposure?

Answer 19

give varicella zoster immunoglobulin (VZIG) within 96 hours of exposure

Question 20

what kind of vaccine is the varicella vaccine?

Answer 20

live, attenuated vaccine that causes an antibody response in 95% of people

Question 21

what kind of vaccine is the zoster vaccine?

Answer 21

live, attenuated vaccine that prevents shingles in 50% of people. give to elderly >50

Question 22

what does HHV-6 do?

Answer 22

causes roseola infantum, with feverx3d, then rash. treated symptomatically. not really diagnosed in lab

Question 23

what’s epstein barr virus?

Answer 23

causes “infectious mono”. 4-7 incubation. associated with burkitt’s lymphoma and naso-pharyngeal carcinoma

Question 24

how to diagnose EBV?

Answer 24

can’t diagnose but can PCR for monitoring immunocompromised patients

Question 25

how to treat for EBV?

Answer 25

no vaccine. protect spleen from trauma.

Question 26

symptoms of cytomegalic inclusion disease?

Answer 26

jaundice, hepatosplenomegaly, petechial rash, microcephaly, cerebral calcifications, chorioretinitis

Question 27

what can you use to diagnose CMV infection?

Answer 27

the whole range of tests - culture, EM, immuno, PCR, serology

Question 28

what’s the treatment for CMV?

Answer 28

none for normal people.

ganciclovir or foscarnet for immunocompromised

Question 29

what does HHV-8 cause in healthy people?

Answer 29

febrile exanthem and maybe mono. it causes kaposi’s sarcoma in immunocompromised hosts

Question 30

how to diagnose HHV-8 infection?

Answer 30

biopsy of skin lesion - can test that.

can’t PCR blood because low viral titres. serology not always available