HIV Diagnosis, Management and Prevention

Question 1

CDC HIV Screening guidelines

Goals:

Answer 1

Treatment for HIV-positive persons

• Avoid undiagnosed, advanced AIDS
• Decrease HIV transmission
• Prevention counseling with HIV-positives
• Viral suppression reduces transmission
• Prevent perinatal HIV transmission

Question 2

HIV screening guidelines

Answer 2

Screen any patient, aged 13-64 once
Any pregnant patient
Annually, if
- IVDU
- Commercial sex worker
- More than 1 sexual partner since last HIV test

Question 3

Why is testing important

Answer 3

Diagnosis allows individuals to get antiretroviral treatment - decreased mortality
- 32% of new HIV cases also diagnosed with AIDS within 1 year

Question 4

Acute retroviral syndrome

Answer 4

2-6 weeks after infection
Primary response to infection
Symptoms:
- Fever
- Arthralgia/myalgia
- anorexia/weight loss
- Rash
- Lymphadenopathy
High levels of viremia
Decreased CD4 cells in circulation

Question 5

Tests for HIV

Answer 5

Antibody tests - negative until 4-6 weeks after infection
- ELISA - screening test
Antigen tests - detect infection after 10-14 days
- p24 antigen
- HIV viral load/RNA
Combination HIV antibody/antigen test

Question 6

Pooled HIV RNA testing

Answer 6

Sample of 20-90 patients combined
Positive pools: test run on progressively smaller pools
Increases yield of HIV testing by up to 10 compared to antibody testing alone

Question 7

HIV treatment concepts
Resistance:
Goals:

Answer 7

Resistance testing prior to treatment
Goals of treatment
- undetectable viral load (<20 copies/uL)
- Increase in CD4 T-cells
- Eliminate HIV-related symptoms

Question 8

Antiretroviral treatment

Answer 8

3 medications
2 classes of drugs
- Nucleoside reverse transcriptase inhibitor (NRTI)
- Nonnucleoside reverse transcriptase inhibitor (NNRTI)
- Protease inhibitor (PI)
- Integrase inhibitor
- Fusion inhibitor
- CCR5 receptor antagonist

Question 9

Additional years survived for HIV positive persons (1995 vs. 2005)

Answer 9

38.9

Question 10

Perinatal transmission (% infected)
Untreated:
One drug (AZT):
Standard of Care:
- HAART
- IV AZT during labor
- AZT to baby x 6 wks

Answer 10

Untreated: 25% infected
One drug (AZT): 8% infected
Standard of Care: 0-1% infected

Question 11

Test and Treat Strategy: Universal HIV testing - Immediate ARVs
Result:

Answer 11

Incidence < 1/1000 in 10 years
Prevalence < 1% in 50 years
8 million AIDS deaths averted

Question 12

Top 3 ways of transmitting HIV

Answer 12

Needle-sharing IDU
Receptive Anal intercourse
Percutaneous Needle Stick

Question 13

Likelihood of transmission per 1 exposure
Hepatitis B:
Hepatitis C:
HIV:

Answer 13

Hepatitis B: 30%
Hepatitis C: 3%
HIV: 0.3%

Question 14

NOT considered Infectious for HIV unless Visibly Bloody

Answer 14

Feces
Saliva
Sputum
Sweat
Tears
Urine
Vomitus

Question 15

ARVs for Post Exposure Prophylaxis

Answer 15

Initiate 2-3 drug therapy ASAP following exposure
No healthcare-related transmissions since 2001
Applicable for sexual exposure to HIV (challenge: timely access to ARVs)

Question 16

Pre-Exposure prophylaxis (PrEP)

Answer 16

• In PrEP, an HIV uninfected individual uses an antiretroviral medication ahead of an HIV exposure
• By having the antiretroviral in blood/tissues, PrEP may make is so that HIV is unable to establish infection
• Analogous to prophylaxis for malaria travelers

Question 17

3 RCTs of Pre-exposure Prophylaxis

Answer 17

iPrEx (men who have sex with men) - 44% protection

Partners PrEP (heterosexual HIV serodiscordant couples - 75% protection

TDF2 (male and female 18-39 years old) - 62% protection