Treatment, Prevention, and Control of Viral Diseases

Question 1

Acyclovir is used to treat what viruses?

Answer 1

1. Herpes in humans
2. Feline herpesvirus-1 induced corneal ulcers
3. Equine herpesvirus-1 induced encephalomyelitis

Question 2

What are options used to treat viral diseases?

Answer 2

1. Antivirals
2. Immune system stimulation
3. Synthesize antibodies or administration of natural antiserum

Question 3

__________ is an antiviral drug primarily restricted to herpesviruses

Answer 3

Acyclovir

Question 4

How does Acyclovir work to treat viruses?

Answer 4

Administered as a prodrug/inactive form

Requires thymidine kinase from herpesvirus infected host cell to convert itself into the active form which blocks viral replication

Question 5

___________ is a synthetic nucleoside analog of deoxyguanosine

Answer 5

Acyclovir

Question 6

How does Acyclovir specifically target viral infected cells without damaging normal uninfected host cells?

Answer 6

Herpesvirus thymidine kinase and herpes virus DNA polymerase are viral enzymes only found in viral infected cells

So acyclovir cannot be phosphorylated and incorporated into the host DNA without herpesvirus

Question 7

__________ inhibits replication of most strains of influenza A viruses

Answer 7

Amantadine

Question 8

What is the mechanism of antiviral amantadine?

Answer 8

1. Targets M2 ion channel
2. Clogs the channel and prevents it from pumping protons into the virion
3. viral RNAs remain bound to M1 and cant enter the nucleus

= blocks uncoating of the virus

Question 8

________ is a neuraminidase inhibitor

Answer 8

Oseltamivir (Tamiflu)

Question 9

What viruses should be treated with neuraminidase inhibitors?

Answer 9

Influenza A and B viruses

these viruses make a neuraminidase enzyme that can be targeted with the drug

Question 10

How does oseltamivir act as an antiviral?

Answer 10

Inhibits / blocks neuraminidase

Question 11

Inhibition of ____________ slows the spread of avian influenza and gives the immune system time to catch up and clear the infection

Answer 11

Neuraminidase

Question 12

What are examples of nucleoside analog reverse transcriptase inhibitors (NRTIs)?

Answer 12

1. Zidovudine (ZDV) / Azidothymidine (AZT)
2. Didanosine (ddI)

Question 13

______ is a nucleoside along of thymine

Answer 13

Zidovudine (ZDV) / Azidothymidine (AZT)

Question 14

______ has been shown to reduce clinical signs in FIV positive cats when administered at 10mg/kg BID, SQ, for 3 weeks

Answer 14

Azidothymidine (AZT)

Question 15

_______ are required to cleave HIV polyproteins into functional proteins

Answer 15

Proteases

Question 16

What are protease inhibitors used for?

Answer 16

To treat HIV

protease inhibitor binds to HIV protease and prevents the enzyme from cleaving HIV polyproteins into single functional, infectious proteins. As a result, HIV can not mature or become infectious

Question 17

How are live attenuated viral vaccines produced?

Answer 17

1. From naturally occurring attenuated viruses
2. By serial passage in cultured cells
3. By serial passage in heterologous hosts
4. By selection of cold-adapted mutants and reassortants

Question 18

How are non replicating virus vaccines produced?

Answer 18

1. From inactivated whole virions
2. From purified native viral proteins

Question 19

What vaccine incorporates a subunit/ portion of a pathogen into the vaccine?

Answer 19

DIVA vax

Question 20

True or False: ZDV-triphosphate competes with dGTP for reverse transcriptase

Answer 20

FALSE - Acyclovir triphosphate competes with dGTP for DNA polymerase

Question 21

What is required for Acyclovir to exert its antiviral effects?

Answer 21

Herpes virus thymidine kinase - converts it from pro drug into the active form

only effective against Herpes virus

Question 22

Vaccines produced by serial passage of viruses in a heterologous host is a ________ vaccine

Answer 22

Live attenuated

Question 23

_______ is used to differentiate vaccinated animals from actually exposed animals

Answer 23

DIVA vax

Question 24

When would an animal be put in isolation?

Answer 24

-if animal is showing CS and/or tested positive on a diagnostic test

Question 25

When would an animal be put in quarantine?

Answer 25

-if animal is EXPOSED to a contagious disease (does not have CS yet)

and/or tested negative on a diagnostic test

Question 26

________ is less effective than sterilization and does not necessarily kill all microbes

Answer 26

Disinfection

Question 27

What is antisepsis?

Answer 27

applying a liquid antimicrobial to skin or living tissue to inhibit or destroy microbes

Question 28

___________ is a process that eliminates many or all pathogenic microbes, except bacterial spores, on inanimate objects

Answer 28

Disinfection

Question 29

Which decontamination technique can destroy bacteria with spores?

Answer 29

Sterilization

Question 30

________ is a term used to describe a process or treatment that renders a device, instrument, or environmental surface safe to handle

Answer 30

Decontamination

Question 31

What sterilization methods are used to prevent and control disease? (5)

Answer 31

1. Moist heat - Autoclave
2. Dry heat - Hot air oven
3. Chemical methods - Ethylene oxide or Ozone gas
4. Radiation
   - non ionizing: UV radiation
   - Ionizing: Gamma rays, X rays
5. Sterile filtration
   - microfiltration using membrane filters

Question 32

Autoclaving is an example of _________

Answer 32

Sterilization by moist heat

Question 33

What chemical gases are used for sterilization?

Answer 33

Ethylene oxide, Ozone