Microbio Week 10 - Antivirals and Diagnostic Virology (Exam 3) Flashcards
Block the release of the influenza virus by blocking the viral neuraminidase
Neuraminidase inhibitors
2 classes of drugs for influenza
Neuraminidase inhibitors
Cap-dependent endonuclease inhibitor
The most common is Tamiflu
Neuraminidase inhibitors
Xofluza prevents the influenza virus from taking cellular mRNA caps and using them to make viral mRNA.
As a result, viral RNA can’t be transcribed into
mRNA, and viral proteins are not made
Cap-dependent endonuclease inhibitor
Not specific to one virus and can be used on respiratory syncytial virus, hepatitis C virus, and hemorrhagic fever viruses
Ribavirin
Works by lowering guanine nucleotides in the cell (by inhibiting inosine monophosphate
dehydrogenase), making viral RNA replication harder
Ribavirin
Also works as a viral RNA-dependent RNA polymerase inhibitor
Ribavirin
A teratogen - two forms of birth control should be used while taking this drug and continued for six months after use
Ribavirin
5 classes of HIV antivirals (ON EXAM)
- Entry inhibitors
2&3. Reverse transcriptase inhibitors (2 classes) - Integrase inhibitors
- Protease inhibitors
Block receptor or co-receptor binding or membrane fusion and entry in HIV
Entry inhibitor
Name the 2 reverse transcriptase inhibitors for HIV
Nucleoside reverse transcriptase inhibitors (NRTI)
Non-nucleoside reverse transcriptase inhibitors (NNRTI)
Chain terminators prevent the chain from being elongated in HIV
Nucleoside reverse transcriptase inhibitors (NRTI)
Bind to reverse transcriptase and prevent its ability to make DNA in HIV
Non-nucleoside reverse transcriptase inhibitors (NNRTI)
Block the ability of the HIV virus to make a DNA copy of itself
Both reverse transcriptase inhibitors
Prevent the HIV virus from inserting the viral DNA into the cellular DNA
Integrase inhibitor
Block the maturation of the viral HIV particle
Protease inhibitor
Name the 3 classes of HCV drugs
- Viral protease inhibitor
- Viral polymerase inhibitor
- Viral protein NS5A inhibitor
Block cleavage of the viral polyprotein and stop replication after this step in HCV
Viral protease inhibitor
Block the ability of the virus to replicate its RNA in HCV
Viral polymerase inhibitor
Block RNA production and assembly in HCV
Viral protein NS5A inhibitor
Block the viral polymerase and interfere with viral DNA production in herpesviruses
Acyclovir compounds
Need to be activated by a viral thymidine kinase
Acyclovir compounds
Preferentially activated in an infected
cell that has the viral thymidine kinase
Acyclovir compounds
Prodrug of acyclovir
Valacyclovir
Converted to acyclovir in the body and requires less dosing than acyclovir
Valacyclovir
Both treat HSV and VZV herpesviruses
Acyclovir
Valacyclovir
Same active compound and can also treat HSV and VZV herpesviruses
Which one is oral and which one is topical?
Famciclovir (oral)
Penciclovir (topical)
Have more side effects and are used to treat the herpesvirus CMV
Valganciclovir
Gangiclovir
Used to confirm a diagnosis
Viral diagnostics
What is necessary for prescribing the correct antiviral drugs?
Diagnosing a virus
What can help monitor chronic infections and the prevalence of a virus in the community?
Viral diagnostics
Viral infections are determined by looking for viral inclusion bodies, syncytia, or using detector antibodies for viral proteins
Cytology
Vaccines require large quantities of _____. And many vaccines are produced in ____________ cells
virus; cultured
Cell culture can be used to diagnose an infection, but what tests are rapidly replacing the need for viral culture?
Nucleic acid tests
Can be used to detect antibodies present in the body against a specific virus
Antibodies or Antigens- ELISA or EIA
The Antibodies or Antigens- ELISA or EIA test can be for IgM, which would indicate what?
Acute infection
The Antibodies or Antigens- ELISA or EIA test can be for IgG, which would specify what?
Acute, chronic, or past infection
They can also be used to test for the presence of a viral antigen indicating active infection
Antibodies or Antigens- ELISA or EIA
The Antibodies or Antigens- ELISA or EIA test is specific to how many viruses?
1
The Antibodies or Antigens- ELISA or EIA can be used to check for vaccine _________
efficacy
T/F: All tests can have false positives or false negatives
True
A quick, easy test that is like an ELISA or EIA
Lateral flow assay
Depending on the test, it can detect the presence of viral antigens or antibodies
Lateral flow assay
T/F: Elisa/EIA and lateral flow assays are quick and can be done in minutes
True
Where can lateral flow assays be done?
At home
Dr’s office
T/F: You do not have to know what virus you have to do a lateral assay test
FALSE, you have to know what virus to test since one virus is tested per assay
The lateral assay test might not pick up the new ________ if the virus undergoes antigen drift
strain
These tests are very sensitive and can amplify small amounts of starting material. They usually pick up an infection if it is present
Nucleic acid amplification tests (NAAT)
A specialized NAAT can determine the amount of what in a person?
Virus
This is often done in chronic infections to determine whether antiviral treatment is working
Nucleic acid amplification tests (NAAT)
Most of the time, these tests are sent to a lab.
This can mean waiting several days for the result.
However, more and more of these tests are marketed for point of care (in
a doctor’s office)
Nucleic acid amplification tests (NAAT)
These tests tend to be more expensive than lateral flow assays
Nucleic acid amplification tests (NAAT)
Can test for several infections at once. Still,
they are costly and usually not done unless the person is hospitalized
Nucleic acid amplification tests (NAAT)
How many people with the disease will test positive
Sensitivity
If 100 people have been infected with influenza and only 70 of them test positive, what is the sensitivity of the test?
70%
How many people who DO NOT have the disease will test negative
Specificity
If 100 people who are not infected with influenza take the test and 5 of them test positive, what is the specificity of the test?
95%
T/F: When the prevalence of infection is low, testing can have limited utility
True
