Lecture 6: HIV

Question 1

how is HIV transmitted

Answer 1

sexually, parentally, through blood, mother to fetus

Question 2

The risk of transmission

Answer 2

depends on the mode of transmission and degree of infectivity of the source. The highest risk of transmission is during receptive anal intercourse (1:100).

Question 3

Mother to child transmission is x without treatment

Answer 3

25%

Question 4

Do we need separate consent for HIV testing?

Answer 4

No but screening should be voluntary and only done if the patient agrees. If patient declines testing- should be documented in chart.

Question 5

Other than semen or blood, fluids that transmit the disease are

Answer 5

breast milk and vaginal fluids

Question 6

CDC recommendations for HIV screening

Answer 6

for all adults ages 13-65 (regardless of risk factors) at least once

Question 7

What is the preferred method of HIV screening? What does it detect?

Answer 7

Fourth generation combination HIV test- detects both HIV-1 and HIV-2 antibodies and HIV-1 p24 antigen

Question 8

For HIV-infected patients successfully treated with ART, what is their life expectancy?

Answer 8

life expectancies are now similar to those in the general population

Question 9

What is the recommended screening for pregnant women?

Answer 9

ALL pregnant women regardless of risk factors each pregnancy (opt-out-screening)

Question 10

What is the preferred method of HIV screening?

Answer 10

Fourth generation combination HIV test

Question 11

P24

Answer 11

(short for protein 24) is a part of HIV-1 virus and can be detected in blood 2 weeks after transmission before antibodies are produced. Therefore, the forth generation test allows early HIV detection when antibody may not yet be detectable (before seroconversion).

Question 12

If the combination test is positive…

Answer 12

then a confirmatory test is needed to differentiate HIV-1 from HIV-2 antibodies. If there is a concern for acute HIV infection, additional testing with HIV RNA (vital load) should be performed. Testing for HIV RNA (viral load) should not be used for screening.

Question 13

Most opportunistic infections occur when CD4 falls below what?

Answer 13

200 with the exception of TB (can occur at any CD4 level). PCP pneumonia (pneumocystis pneumonia) is the most common opportunistic infection and a leading cause of death in patients with AIDS.

Question 14

How does acute HIV infection present?

Answer 14

as mononucleosis type illness (fever, malaise, myalgia, sore throat, rashes) in patients with risk factors

Question 15

If acute HIV is suspected what should you order?

Answer 15

HIV viral load (HIV RNA) and the forth generation combination test (HIV antibodies + HIV-1 antigen) should be ordered.

Question 16

In US, when do we start treatment?

Answer 16

antiretroviral therapy (ART) should be initiated in nearly all HIV-infected individuals regardless of their CD4 count or presenting symptoms at the time of the diagnosis (after initial assessment).

Question 17

significant drug interactions with HIV meds?

Answer 17

increased statins level (especially, simvastatin) and increased corticosteroid levels with protease inhibitors. Increased corticosteroid level may cause Cushing syndrome.

Question 18

Most opportunistic infections occur when CD4 falls below what?

Answer 18

200 with the exception of TB (can occur at any CD4 level)

Question 19

Post-exposure prophylaxis (sexual contact, needle stick) with antiretroviral medications (combination of medications) is recommended when?

Answer 19

if an individual had (1) an exposure to a source known to be HIV infected, AND (2) exposure was within 72 hours of presentation AND (3) exposure was to a fluid that could contain HIV virus (blood, semen, vaginal secretions). Post-exposure prophylaxis is not indicated for intact skin exposures and urine-source exposures. Start treatment as soon as possible.

Question 20

concerns of non-HIV related comorbidities

Answer 20

• HIV infection is associated with a 50% higher risk of acute myocardial infarction beyond that explained by traditional risk factors (likely due to chronic inflammation and dyslipidemia caused by antiretroviral medications). Cognitive changes progressing to dementia are more prevalent in patients with HIV. HIV-associated cognitive changes can occur despite appropriate HIV control and adherence to antiviral therapy. People with HIV have elevated risk for non-Hodgkin lymphoma (x 77 higher) and cervical cancer (x 6 higher).

Question 21

CD4 count significance

Answer 21

Assess status of immune system and a risk for opportunistic infections

Question 22

When to order CD4 count?

Answer 22

Every 3-4 months for HIV infected patients to assess risk for opportunistic infections (falling CD4 count= an increased risk and poor prognosis)

Question 23

Acute HIV infection presents as

Answer 23

mononucleosis type illness (fever, malaise, myalgia, sore throat, rashes) in patients with risk factors. If acute HIV is suspected, HIV viral load (HIV RNA) and the forth generation combination test (HIV antibodies + HIV-1 antigen) should be ordered.

Question 24

The forth generation combination test cannot be used alone since

Answer 24

it is less sensitive than HIV RNA for detection of acute HIV infection. Viral load is very high during acute HIV infection therefore it is likely to be detected.

Question 25

standard of care treatment

Answer 25

Combination of ART medications. •The main reason for combining medications is to reduce drug resistance. ART medications inhibit the HIV virus replication (making copies of itself), which reduces the amount of virus in the body. Having less HIV virus allows the immune system to maintain functions to fight opportunistic infections and cancers. HIV virus is suppressed but not eliminated (even in patients with undetectable viral load); therefore, the treatment is life-long (to keep the virus suppressed as long as possible). The goal of the therapy is to drive down viral load to undetectable level. ART therapy prolongs survival and decreases HIV transmission. Adherence to the ART regimen is a key determinate in the degree and duration of viral suppression.

Question 26

HIV viral load (HIV RNA) is used

Answer 26

to (1) diagnose acute HIV, (2) assess response to the treatment (treatment failure FIRST manifests with a rising HIV viral load!). It is the best indicator for HIV virus activity and infectivity.

Question 27

CD4

Answer 27

a surface molecule of T-helper lymphocyte and a target of the HIV virus. HIV virus causes continuous T-lymphocytes destruction. CD4 count is a good indicator of disease severity and level of immunity.

Question 28

Most infections happen when the CD4 falls <

Answer 28

200 with the exception of TB (can occur at any CD4 level).

Question 29

Vaccines contraindicated with HIV

Answer 29

Live vaccines (MMR, Zoster, Varicella, yellow fever) • are contraindicated in HIV individuals with significant immunosuppression (CD4 count less than 200).

Question 30

Pre-exposure prophylaxis to

Answer 30

prevent sexual acquisition of HIV is recommended to HIV-negative individuals at high-risk (men who have sex with men, multiple sexual contacts, HIV discordant heterosexual couples). In 2012, the FDA approved Truvada (once daily) for pre-exposure prophylaxis. With adherence, Truvada prevents 92% of infections.

Question 31

test: HIV viral load (HIV RNA) significant to

Answer 31

Diagnose acute HIV infection, Monitor response to treatment

Question 32

HIV viral load (HIV RNA) when to order it

Answer 32

• If acute infection is suspected

- Every 3-4 months for HIV patients who receive ART to monitor response (rising viral load= treatment failure)

Question 33

Combination test of HIV-1 and HIV-2 antibodies and HIV p24 antigen significance

Answer 33

Screening for HIV infection in asymptomatic individuals. Negative test do not require any additional tests.
Positive test requires confirmation with HIV-1/HIV-2 differentiation assay

Question 34

Combination test of HIV-1 and HIV-2 antibodies and HIV p24 antigen when to order

Answer 34

• Screen for asymptomatic HIV infection

- Test for acute HIV infection in addition to HIV viral load (HIV RNA)