Blood borne Viruses

Question 1

Human Immunodeficiency virus

Answer 1

Enveloped with linear, dimeric, ssRNA (+) genome
Family: Retroviridae
Species: HIV 1 and 2
4 groups: M, N, O, P
M subtypes: A to K
In the Americas: group M, subtype B is dominant

Question 2

3 stages of HIV disease

Answer 2

1. Primary infection: Acute stage, 3-6 weeks, mononucleosis-like syndrome (fever, maculopapular rash, oral ulcers lymphadenopathy, malaise, weight loss, arthralgia, night sweats)
2. Clinical latency: years, despite no symptoms, active replication occurs if untreated
3. AIDS: opportunistic infections and/or tumors

Question 3

When should you give HIV post-exposure prophylaxis

Answer 3

Within 2 hours of exposure is best

May not be effective after 72 hours

Question 4

What type of treatment do you use for HIV?

Answer 4

Highly active antiretroviral therapy (HAART)

Question 5

4 Lab diagnostic tests for HIV

Answer 5

1. HIV screening assays
2. Confirmatory testing
3. Viral loads to monitor treatments
4. Antiviral resistance testing

Question 6

Why should you always use a 4th generation EIA for HIV?

Answer 6

It detects antibodies to HIV as well as an HIV antigen (P24 antigen)
Reduce the window period!

Question 7

Hepatitis C virus

Answer 7

ssRNA (+), enveloped
Fam: Flaviviridae, Gen: Hepacivirus
Genotypes 1 to 6

Question 8

Hep C signs and symptoms

Answer 8

Abdominal pain
Jaundice
Nausea/vomiting
Swollen abdomen
Itchy skin
Weight loss

Question 9

What enzyme is used as a marker for liver damage?

Answer 9

Alanine aminotransferase

Question 10

Why do we need to do HCV genotyping?

Answer 10

Helps determine treatment and duration

Question 11

Direct acting antivirals (3) for HCV

Answer 11

RNA Replicase inhibitors (2 types)
Protease inhibitors
NS5A inhibitors

Question 12

How to monitor HCV viral loads

Answer 12

Real time RT-PCR performed over time reveals treatment success or failure

Question 13

Hepatitis B virus

Answer 13

Enveloped, partially dsDNA
Encodes a reverse transcriptase (like HIV)
Fam: Hepadnaviridae, gen: orthohepadnavirus
Perinatal and horizontal transmission (child to child, contaminated needed, sexual contacts, healthcare worker, blood transfusion)

Question 14

Treatment for HBV

Answer 14

alpha-interferon
Lamivudine
Newer agents..

Question 15

5 drugs to treat HIV

Answer 15

1. Nucleoside and non-nucleoside reverse transcriptase inhibitors (NRTIs and NNRTIs) - most common
2. Fusion inhibitors
3. Protease inhibitors
4. Integrase inhibitors
5. CCR5 co receptor antagonists