viral infections

Question 1

viral transmission

Answer 1

aerosol, contact, droplet, vector, fomite,
waterborne, bloodborne, foodborne,
vertical

Question 2

replication of virus

Answer 2

dependent on virus ability to invade the host cell (obligatory intracellular microbes)

Question 3

viral evasion of host defences

Answer 3

mutations
latency
immune suppression
rapid replication

Question 4

structure of a virion

Answer 4

enveloped vs non-eveloped
essential enzymes
capsid protein layer
viral genome

Question 5

Antigenic drift

Answer 5

minor change
* due to small mutations in surface proteins
* previous infections may offer partial protection
* potential to cause epidemics

Question 6

Antigenic shift

Answer 6

major change, rapid
* can produce completely new viral sub-types
* associated with Influenza A viruses which have a broad host range (humans, birds,
mammals)
* potential to cause pandemics

Question 7

HA of influenza

Answer 7

hemagglutinin
allows binding to + entering of respiratory epithelial cells

Question 8

NA of influenza

Answer 8

neuraminidase
releases new virions from infected host cells

Question 9

enveloped virus

Answer 9

outer lipid layer that contains crucial glycoproteins (spikes) for attaching to + entering host cells
(i.e., influenza viruses, herpesvirus, coronaviruses)

Question 10

non-enveloped virus

Answer 10

more resistant to environmental conditions such as temperature, pH, + detergents
(i.e., poliovirus, rhinovirus, adenoviruses)

Question 11

drugs for influenza

Answer 11

oseltamivir (PO)
zanamivir (inhalation)

Question 12

MOA of oseltamivir

Answer 12

NEURAMINIDASE INHIBITORS

Question 13

Viral latency of HSV

Answer 13

in dorsal root ganglia (lifelong)

Question 14

treatment of HSV

Answer 14

acyclovir

Question 15

Post-herpetic neuralgia of VZV

Answer 15

Neuropathic pain persisting in a dermatome at least 3 months after lesions have resolved

Common complication of herpes zoster

Topical or systemic pain relief often required

Early antiviral initiation can reduce incidence + severity

Question 16

MOA of acyclovir

Answer 16

nucleoside analogs
inhibits synthesis of viral DNA = inhibition of viral replication

Question 17

adverse effects of acyclovir

Answer 17

nephrotoxicity
neurotoxicity
DRESS with valacyclovir (drug reaction with eosinophilia + systemic symptoms),
TTP/HUS with valacyclovir (thrombotic thrombocytopenic purpura/hemolytic uremic syndrome)

Question 18

valacyclovir prodrug of

Answer 18

(prodrug of acyclovir, ↑ bioavailability) (PO)

Question 19

famciclovir prodrug of

Answer 19

prodrug of penciclovir

Question 20

Primary genital HSV infections risk _________transmission, during
treatment and prophylaxis

Answer 20

Primary genital HSV infections risk vertical transmission, especially in the 1st and 3rd trimesters, and should be treated with acyclovir.
Prophylaxis with acyclovir or valacyclovir from 36 weeks until delivery is indicated if there has been a prior infection within the past year