oral viral infections

Question 1

eg of DNA virus & RNA virus

Answer 1

DNA - herpes
RNA - mumps

Question 2

eg of viral replication of DNA virus (8)

Answer 2

herpes
1. binding
2. entry
3. release & nuclear transport
4. nuclear entry
5. gene expression
6. DNA replication
7. packaging
8. egress

Question 3

basic serology

Answer 3

IgM = primary immune antibody response
IgG = secondary / immunological response

Question 4

common features of HSV (3)

Answer 4

primary infection
latency
recurrent infection

Question 5

clinical features of HSV 1&2

Answer 5

gingivostomatitis
herpes labialis
keratoconjunctivitis
herpetic whitlow
bell’s palsy
genital herpes

Question 6

herpes simplex pathogenesis (4)

Answer 6

1. acute infection
2. latency - retrograde transport
   (to trigeminal ganglion)
3. reactivation (anterograpde transport)
4. 2ndary infection i.e. cold sores

Question 7

tx of HSV

Answer 7

aciclovir 200mg x 5 for 5 days
aciclovir cream 5% 2g apply every 4hrs (5xdaily) for 5 days

Question 8

varicella virus

Answer 8

chicken pox
incubation = 10-21 days
complications = 2ndary bacterial infections, pneumonia, congenital, peri/neonatal

Question 9

zoster virus

Answer 9

shingles
vesicles in dermatome representing cranial / spinal ganglia where virus has been dormant
complications = post herpetic neuralgia / 2ndary bacterial infection / ophthalmic zoster / ramsay hunt syndrome

Question 10

varicella zoster pathogenesis

Answer 10

primary infection
latency
recurrent infection

Question 11

varicella zoster tx

Answer 11

aciclovir tablets 800mg 5 x daily for 7 days

Question 12

aciclovir mechanism of action

Answer 12

inhibits DNA polymerase
active only in infected cells
competitively inhibits acts as defective guanine molecule which is then incorporated into growing strand and causes preferential termination of viral DNA synthesis