HIV

Question 1

Describe the characteristics of retroviruses

Answer 1

1. Subfamilies of retroviruses
   a) Oncoviruses (HTLV-1, HTLV-2)
   b) Lentiviruses (HIV-1, HIV-2)
2. AIDS
   a) HIV positive, less than 200 CD4 cells, or an AIDS indicator disease
3. Enveloped, positive-strand RNA virus that encodes reverse transcriptase
4. Replicate through a DNA intermediate
5. The DNA copy is integrated into the host chromosome to become a cellular gene

Question 2

What are the charateristics of retroviruseswhere and who discovered retrovirus

Answer 2

1. HIV-1 discovered in 1981 by Gallo and Montagnier
2. Subsequently, HIV-2 was isolated in West Africa

Question 3

Describe the epidemiology of Retrovirus (HIV)

Question 4

Where is HIV present

Answer 4

1. In blood (or fluids contaminated by blood and serum)
2. semen
3. vaginal fluids

Question 5

Describe the host related factors that can increases the infectiousness of HIV

Answer 5

1. primary infection – high viral load
2. late-stage infection – high viral load
3. genital tract infections – mucosal breech and recruitment of inflammatory cells

Question 6

What is the percentage of people who do not know they have HIV

Answer 6

approx 15%

Question 7

what is the percentage of children who obtain HIV from their mother

Answer 7

1 in 4 = 25%

Question 8

what is the percentage of children who obtain HIV from their mother with older Tx

Answer 8

4%

Question 9

what is the percentage of children who obtain HIV from their mother with HAART Tx

Answer 9

less than o.5%

Question 10

How does HIV replicate

Answer 10

1. gp120 interacts with the CD4 surface molecule expressed on helper T lymphocytes and cells of macrophage lineage = macrophages, dendritic cells, and microglial cells (brain cells)
2. HIV enters the cell by fusion with the cellular envelope
3. After release, the reverse transcriptase
   synthesizes a complementary DNA strand
4. A copy of the DNA strand is then produced
5. Integrated into our genome by Integrase; Once integrated, viral DNA is transcribed like
   other host genes
6. Each copy contains approximately five errors
   or mutations

Question 11

What does HIV infection of CD$ lymphocytes result in and how

Answer 11

1. results in cell death by a direct effect or by apoptosis (programmed cell death)
2. loss of cell mediates immunity and in opportunistic and malignancies occur

Question 12

when does aids develop

Answer 12

when any number of signs of CD4 depletion occur

Question 13

describe the signs of CD4 depletion for opportunistic infections

Answer 13

1. oral candidiasis
2. toxoplasmosis
3. cryptococcal meningitis
4. severe herpes infections
5. cytomegalovirus infections
6. tuberculosis
7. Pneumocystis pneumonia

Question 14

describe the signs of CD4 depletion for Maligancies

Answer 14

1. Kaposi’s sarcoma
2. Lymphoma
3. Cervical cancer

Question 15

Besides opportunistic infections and malignancies what are other signs of signs of CD4 depletion

Answer 15

1. Aids related dementia
2. wasting syndrome

Question 16

what is the window period for HIV mean

Answer 16

time between infection and lab detection

Question 17

what does seroconversion mean

Answer 17

HIV-infected patients will eventually generate anti-HIV antibodies

Question 18

How do you test for HIV

Answer 18

1. If testing occurs too early, the result will be falsely negative …test over time
2. If HIV screen is positive …confirm the result to avoid false positives
3. Two-tiered serologic testing

Question 19

How do you screen for HIV

Answer 19

1. By using Enzyme immunoassay (EIA) or chemiluminescent microparticle immunoassay (CMIA)
   a) 4th generation assays detect both HIV antigen and antibodies
2. Serology
   a) tests for antibodies to viral antigens by enzyme immunoassays
3. Immunologic studies
   a) CD4 counts
4. Viral load testing
   a) PCR quantification of RNA in plasma
5. Resistance genotyping
   a) looking at the sequences of the genes in the
   HIV to see if there are mutations that cause resistance

Question 20

What are the advantages of HIV-1 / HIV-2 immunoblot (confirmatory)

Answer 20

1. Rapid – 30 min.
2. More specific
3. Confirmation of both HIV-1 and HIV-2

Question 21

what are the goals of HIV therapy

Answer 21

1. Maximal and durable suppression viral load
2. Restoration or preservation of immune function
3. Improvement in quality of life
4. Reduction of HIV morbidity & mortality
5. Preservation of future treatment options

Question 22

wjhat is Quantitative RT-PCR (“viral load”) used for in HIV

Answer 22

Used to monitor antiretroviral therapy over time

Question 23

During a needle stick exposure of HIV what does the risk of infectiondepend on

Answer 23

1. Stage of the patient’s disease
2. How much blood (hollow vs solid, gauge of needle, aspiration vs injection)

Question 24

what do you do if you have a needle stick exposure of HIV

Answer 24

1. Confirm patient’s status
2. Document your status
3. Begin antiviral prophylaxis

Question 25

To be effective PPE must begin within how many hours

Answer 25

72 hours of exposure 2hrs of exposure best