4/30 Quiz and Review: HIV + small group

Question 1

Is transplacental transmission possible?

How does most of vertical transmission take place?

Answer 1

transplacental transmission = possible; not very common though.

Most of vertical transmission (mom to kid) occurs during delivery (or via breastfeeding)

Question 2

What is the risk of getting HIV if you are the receptive anal partner, no condom, HIV+ partner, not on antiretrovirals?

Answer 2

1/100

Question 3

Reminder about pyroptosis: when does this occur? what enzyme is involved?

why is it significant?

Answer 3

Pyroptosis = type of cell death that we now know is prominent with HIV infection.

Triggered when intracellular sensor in host cell detects invasion from virus. Uses different enzymatic pathway from apoptosis (caspase 1 v caspase 3).

Impt: leads to different drugs to block this new pathway, some of which we already possess.

Question 4

Survival with HIV/AIDS is much better now than in the 80s/90s…. why is there still a rapid dropoff at the start of a patient’s HIV infection?

Answer 4

Initial drop (upper left of graph) - a patient might die before we are able to get their disease under control.

Once we get it under control, the HIV+ life expectancy vs control population looks pretty similar. Life expectancy is approaching that of an uninfected population.

Question 5

Bilateral infiltrates in HIV+ patient is classic for what?

Answer 5

Pneumocystis jiroveci (PCP)

Question 6

Kaposi’s sarcoma (KS) caused by what virus?

is there a connection between KS and MSM?

Answer 6

Caused by HHV 8

There is a connection between KS and MSM that we don’t understand. More MSM have KS than IVDU, and we rarely see women with KS.

Question 7

what are some reasons why an HIV test might come back “indeterminant”?

Answer 7

• pt is in process of seroconverting - some viral load but not a lot
• false positive (in which case wait a few weeks and re-test with ELISA)
• if patient has HIV2 (rare) a test for HIV1 will come back indeterminant

Question 8

Generally, why do we test with serology (ie, ELISA) rather than HIV viral load via PCR?

Answer 8

HIV serology overall (ELISA/Western blot) are the most sens and specific tests that we probably have. 99.99%+ sens and specific.

Viral load/PCR is more expensive. False positives do happen, in which case the patient may be very anxious while awaiting the serology.

Reasons to do the viral load/PCR: s/s of acute illness or seroconversion.

Question 9

An HIV+ patient with CD4 count of 90 has how many discrete indications for starting drug prophylaxis? what are they and what med should we use?

Answer 9

Two reasons to start meds:

1. PJP (cutoff = CD4 count of 200)
2. Toxoplasma (cutoff = CD4 count of 100)

Prophy for both is TMP/SMX

Question 10

Prevention strategies for a MSM with an HIV+ partner?

Answer 10

• condoms
• doing less risky sex acts
• Pre-exposure prophylaxis (controversial; variant of HAART therapy. good idea for commercial sex workers?!)
• circumcision
• have a partner with a low viral load/on antivirals
• generally look after own health; treat other STIs etc
• Post-Exposure prophy if suspected exposure (28d regimen)