HIV

Question 1

What is the initial screening test for HIV in Canada?

Answer 1

4th generation HIV Ag/Ab combination assay

This test is used for early detection of HIV infection.

Question 2

What does a 4th generation HIV test detect? Name TWO.

Answer 2

• HIV-1/2 antibodies
• p24 antigen

These components help in identifying the presence of HIV in the body.

Question 3

What is the confirmatory test after a positive screening test?

Answer 3

HIV-1/HIV-2 differentiation immunoassay

This test confirms the specific type of HIV present.

Question 4

What test is used in suspected acute HIV with negative serology?

Answer 4

HIV RNA (viral load / NAT)

This test detects the actual virus in the blood.

Question 5

Name THREE symptoms of acute HIV seroconversion.

Answer 5

• Fever
• Rash (maculopapular)
• Pharyngitis
• Lymphadenopathy
• Myalgias (any 3)

These symptoms often occur within 2-4 weeks after infection.

Question 6

What is a key distinguishing feature of acute HIV vs mono?

Answer 6

Absence of exudative tonsillitis (often)

This helps differentiate between the two conditions during diagnosis.

Question 7

When should ART be started after HIV diagnosis?

Answer 7

Immediately (as soon as possible, regardless of CD4)

Early initiation of ART improves health outcomes.

Question 8

Name THREE classes of ART.

Answer 8

• NRTIs
• NNRTIs
• Integrase inhibitors
• Protease inhibitors (any 3)

These classes of medications are used to manage HIV infection.

Question 9

What is the preferred first-line ART backbone (name ONE regimen)?

Answer 9

• Integrase inhibitor + 2 NRTIs

Example: dolutegravir + tenofovir + emtricitabine.

Question 10

When do you start PCP prophylaxis?

Answer 10

CD4 < 200

This threshold indicates a higher risk for opportunistic infections.

Question 11

First-line agent for PCP prophylaxis?

Answer 11

TMP-SMX

This medication is effective in preventing Pneumocystis pneumonia.

Question 12

When do you stop PCP prophylaxis?

Answer 12

CD4 > 200 for ≥3 months on ART

This indicates improved immune function.

Question 13

When do you start MAC prophylaxis?

Answer 13

CD4 < 50

This is crucial for preventing Mycobacterium avium complex infections.

Question 14

First-line MAC prophylaxis?

Answer 14

Azithromycin

This antibiotic is used to prevent MAC in high-risk patients.

Question 15

What are the TWO key labs to monitor in HIV?

Answer 15

• CD4 count
• Viral load

Monitoring these helps assess the effectiveness of treatment.

Question 16

What indicates good response to ART? Name TWO.

Answer 16

• Undetectable viral load
• Rising CD4 count

These factors show that the treatment is effective.

Question 17

Most common OI in HIV?

Answer 17

Pneumocystis jirovecii pneumonia

This is a significant risk for individuals with advanced HIV.

Question 18

CD4 < 100 → risk of which infection? Name ONE.

Answer 18

• Toxoplasmosis
• Cryptococcosis

These infections are common in immunocompromised patients.

Question 19

CD4 < 50 → risk of which infection?

Answer 19

Mycobacterium avium complex

This infection poses a serious threat to patients with very low CD4 counts.

Question 20

What is the goal viral load in pregnancy?

Answer 20

Undetectable

This minimizes the risk of mother-to-child transmission.

Question 21

When is C-section recommended in HIV pregnancy?

Answer 21

Viral load > 1000 copies/mL near delivery

This is to prevent transmission during birth.

Question 22

Can patients with HIV breastfeed in Canada?

Answer 22

❌ No (formula feeding recommended)

This is to reduce the risk of HIV transmission through breast milk.

Question 23

When should PEP be started?

Answer 23

Within 72 hours

Timely initiation is crucial for effectiveness.

Question 24

Duration of PEP?

Answer 24

28 days

This is the standard treatment duration for post-exposure prophylaxis.

Question 25

Name **ONE indication for PrEP**.

Answer 25

**High-risk sexual exposure** (e.g., MSM, serodiscordant partner) ## Footnote PrEP is used to prevent HIV infection in at-risk populations.

Question 26

What CD4 threshold defines **AIDS**?

Answer 26

**< 200 OR AIDS-defining illness** ## Footnote This classification is essential for diagnosis and treatment.

Question 27

Name **ONE AIDS-defining illness**.

Answer 27

* Kaposi sarcoma * Pneumocystis jirovecii pneumonia * Esophageal candidiasis ## Footnote These conditions indicate advanced HIV infection.

Question 28

What is **U=U**?

Answer 28

**Undetectable = Untransmittable** ## Footnote This concept emphasizes the importance of viral suppression in preventing transmission.