HIV

Question 1

The laboratory test generally accepted as the best indicator of the immediate state of immunologic competence of the patient with HIV infection.

Answer 1

CD4 count

Question 2

Patients with CD4+ T-cell counts ______ are at high risk of disease from P. jirovecii

Answer 2

<200/μL

Question 3

Patients with CD4+ T-cell counts _____ are also at high risk of disease from CMV, mycobacteria of the M. avium complex (MAC), and/or T. gondii

Answer 3

<50/ μL

Question 4

Patients with HIV infection should have CD4+ T-cell measurements performed at ______ and ______ thereafter

Answer 4

the time of diagnosis, every 3–6 months

Question 5

CDC HIV Infection Stage 3 in patients more than 5 years old is defined as CD4 count of?

Answer 5

<200

*Stage 1 - >500
Stage 2 - 200-499
Stage 3 - <200

Question 6

The most common cause of HIV disease throughout the world

Answer 6

HIV 1

Question 7

When should the plasma HIV RNA level be measured?

Answer 7

at the time of HIV diagnosis and every 3–6 months thereafter in the untreated patient.

Question 8

The average length of time from HIV initial infection to the development of clinical disease

Answer 8

10 years

Question 9

TRUE OR FALSE: A diagnosis of AIDS is made in any individual age 6 years and older with HIV infection and a CD4+ T-cell count <200/μL and in anyone with HIV infection who develops one of the HIV-associated diseases considered to be indicative of a severe defect in cell-mediated immunity

Answer 9

TRUE

Question 10

It is the single most common cause of pneumonia in patients with HIV infection in the United States and can be identified as a likely etiologic agent in 25% of cases of pneumonia in patients with HIV infection

Answer 10

P. jirovecii

*Pneumocystis pneumonia (PCP) is caused by the fungus P. jirovecii and was once the hallmark of AIDS

Question 11

The risk of PCP is greatest among those who have experienced a previous bout of PCP and those who have CD4+ T-cell counts of ______

Answer 11

<200/μL

Question 12

The standard treatment for PCP or disseminated pneumocystosis

Answer 12

trimethoprim-sulfamethoxazole (TMP-SMX).

Question 13

The treatment of choice for severe disease in the patient unable to tolerate TMP-SMX.

Answer 13

IV Pentamidine

Question 14

What additional medication can be given for patients with a Pao2 <70 mmHg or with an a–a gradient >35 mmHg

Answer 14

Glucocorticoid

Question 15

The preferred regimen for PCP prophylaxis.

Answer 15

TMP-SMX, one double-strength tablet daily

• This regimen also provides protection against toxoplasmosis and some bacterial respiratory pathogens

Question 16

When is prophylaxis for PCP indicated for any HIV-infected individual?

Answer 16

1) HIV-infected individual who has experienced a prior bout of PCP
2) any patient with a CD4+ T-cell count of <200/μL or a CD4 percentage <15
3) any patient with unexplained fever for >2 weeks
4) any patient with a recent history of oropharyngeal candidiasis

Question 17

Indications to discontinue PCP prophylaxis

Answer 17

patients treated with ART who maintain good suppression of HIV (<50 copies/mL) and CD4+ T-cell counts >200/μL for at least 3 months.

Question 18

AIDS pandemic is primarily caused by the ____

Answer 18

HIV-1 M group viruses.

Question 19

Two major envelope proteins if the HIV virion

Answer 19

• the external gp120
  
  • the transmembrane gp41

Question 20

Two major co-receptors for HIV-1

Answer 20

CCR5 and CXCR4

Question 21

Among the parenteral type of exposure in HIV, which carries the highest risk of exposure?

Answer 21

Blood transfusion

Question 22

TRUE OR FALSE: Receptive anal intercourse carries the highest risk of HIV transmission

Answer 22

TRUE

Question 23

When should HIV testing be repeated if the patient’s HIV 1 western blot showed indeterminate result?

Answer 23

4-6 weeks

Question 24

the leading infectious cause of meningitis in patients with AIDS

Answer 24

Fungal meningitis

• vast majority of these are due to C. neoformans

Question 25

TRUE OR FALSE: The diagnosis of cryptococcal meningitis is made by identification of organisms in spinal fluid with india ink examination or by the detection of cryptococcal antigen.

Answer 25

TRUE

Question 26

The diagnosis of this disease is usually suspected on the basis of MRI findings of multiple lesions in multiple locations

Answer 26

Cerebral Toxoplasmosis

Question 27

Initial treatment regimen for cryptococcal meningitis

Answer 27

Initial treatment is with IV amphotericin B 0.7 mg/kg daily, or liposomal amphotericin 4–6 mg/kg daily, with flucytosine 25 mg/kg 4x a day for at least 2 weeks if possible

Question 28

Standard regimen for toxoplasmosis

Answer 28

Standard treatment is sulfadiazine and pyrimethamine with leucovorin as needed for a minimum of 4–6 weeks

Question 29

It is one of the most devastating consequences of HIV infection that usually presents as a painless, progressive loss of vision

Answer 29

CMV retinitis

Question 30

What is the standard therapy for CMV retinitis ?

Answer 30

oral valganciclovir, IV ganciclovir, or IV foscarnet,

• A 3-week induction course is followed by maintenance therapy with oral valganciclovir.
• Maintenance therapy is continued until the CD4+ T-cell count remains >100 μL for >6 months

Question 31

Which of the following best describes Stage 3 (AIDS) in the CDC classification system for HIV?
A) CD4+ T-cell count between 500-1000/μL
B) Presence of any opportunistic infection regardless of CD4+ count
C) CD4+ T-cell count <200/μL or diagnosis of an AIDS-defining illness
D) Presence of HIV RNA but no detectable antibodies

Answer 31

Answer: C) CD4+ T-cell count <200/μL or diagnosis of an AIDS-defining illness
Rationale: Stage 3 (AIDS) is classified by either a CD4+ count below 200/μL or the presence of one or more opportunistic infections, regardless of CD4+ levels.

Question 32

What is the primary mode of HIV transmission worldwide?
A) Injection drug use
B) Blood transfusions
C) Heterosexual contact
D) Mother-to-child transmission

Answer 32

Answer: C) Heterosexual contact
Rationale: While injection drug use and blood transfusions can transmit HIV, the most common mode of transmission globally is heterosexual contact, especially in developing countries.

Question 33

Which of the following HIV proteins is responsible for binding to the CD4 receptor on host cells?
A) gp41
B) gp120
C) Reverse transcriptase
D) Integrase

Answer 33

Answer: B) gp120
Rationale: gp120 is the external envelope protein of HIV that binds to the CD4 receptor on host cells, initiating viral entry.

Question 34

What is the most important factor in determining the risk of sexual transmission of HIV?
A) The presence of STIs
B) The HIV-positive partner’s viral load
C) The type of sexual contact
D) The use of oral contraceptives

Answer 34

Answer: B) The HIV-positive partner’s viral load
Rationale: Viral load is the strongest predictor of HIV transmission risk, with the highest risk occurring during acute infection and late-stage disease.

Question 35

Which of the following is TRUE regarding “Undetectable = Untransmittable” (U=U)?
A) People with undetectable HIV RNA cannot transmit the virus sexually
B) People with undetectable HIV RNA are cured of HIV
C) Antiretroviral therapy (ART) eliminates HIV from the body completely
D) Having an undetectable viral load means HIV cannot be transmitted by any means

Answer 35

Answer: A) People with undetectable HIV RNA cannot transmit the virus sexually
Rationale: Studies have confirmed that when HIV viral load is suppressed below detectable levels with ART, the risk of sexual transmission is effectively zero.

Question 36

Which opportunistic infection is most commonly associated with a CD4+ T-cell count <50/μL?
A) Pneumocystis jirovecii pneumonia (PCP)
B) Cryptococcal meningitis
C) Mycobacterium avium complex (MAC)
D) Kaposi’s sarcoma

Answer 36

Answer: C) Mycobacterium avium complex (MAC)
Rationale: MAC infection is a major concern in patients with CD4+ counts below 50/μL, and primary prophylaxis is recommended unless ART is immediately initiated.

Question 37

What is the preferred first-line prophylaxis for Pneumocystis jirovecii pneumonia (PCP)?
A) Azithromycin
B) Trimethoprim-sulfamethoxazole (TMP-SMX)
C) Isoniazid
D) Amphotericin B

Answer 37

Answer: B) Trimethoprim-sulfamethoxazole (TMP-SMX)
Rationale: TMP-SMX is the preferred prophylactic treatment for PCP in HIV patients with CD4+ counts <200/μL.

Question 38

Which of the following describes a paradoxical immune reconstitution inflammatory syndrome (IRIS)?
A) Worsening of pre-existing opportunistic infection after starting ART
B) Development of new opportunistic infections after starting ART
C) Immediate clearance of opportunistic infections following ART initiation
D) Resistance to antiretroviral drugs leading to treatment failure

Answer 38

Answer: A) Worsening of pre-existing opportunistic infection after starting ART
Rationale: Paradoxical IRIS occurs when the immune system recovers rapidly after ART initiation, leading to an exaggerated inflammatory response against a known infection.

Question 39

What is the standard initial regimen for HIV treatment?
A) Single-drug therapy with a protease inhibitor
B) Two nucleoside/nucleotide reverse transcriptase inhibitors + a third agent
C) A combination of three protease inhibitors
D) Monotherapy with a non-nucleoside reverse transcriptase inhibitor

Answer 39

Answer: B) Two nucleoside/nucleotide reverse transcriptase inhibitors + a third agent
Rationale: The standard first-line HIV regimen includes two NRTIs plus either an NNRTI, integrase inhibitor, or a boosted protease inhibitor.

Question 40

When should ART be initiated in HIV-positive, antiretroviral-naive patients with a CD4 count >50 cells/μL and newly diagnosed TB?
A) Immediately
B) After 1 week of TB treatment
C) 2–4 weeks after starting TB treatment
D) After completing TB treatment

Answer 40

Answer: C) 2–4 weeks after starting TB treatment
Rationale: For patients with CD4 counts >50 cells/μL, delaying ART for 2–4 weeks reduces the risk of immune reconstitution inflammatory syndrome (IRIS) while allowing TB therapy to begin.

Question 41

How should ART be managed in patients with HIV and CD4 counts <50 cells/μL who are diagnosed with TB?
A) ART should be delayed until TB treatment is completed
B) ART should be started as soon as possible
C) ART should only be initiated if TB treatment fails
D) ART should be given only after a CD4+ count increase

Answer 41

Answer: B) ART should be started as soon as possible
Rationale: For patients with very low CD4 counts (<50 cells/μL), the benefits of immediate ART outweigh the risks of IRIS, so ART should be initiated promptly.

Question 42

What is unmasking IRIS?
A) A reaction to ART causing hypersensitivity
B) IRIS related to a previously undiagnosed infection
C) IRIS occurring only in patients with high CD4+ counts
D) A false positive result for an opportunistic infection

Answer 42

Answer: B) IRIS related to a previously undiagnosed infection
Rationale: Unmasking IRIS occurs when ART leads to an inflammatory response against a previously unrecognized infection.

Question 43

Which group is most at risk for developing IRIS after starting ART?
A) Patients with CD4+ counts >500 cells/μL
B) Patients with undetectable HIV RNA before ART
C) Patients with CD4+ counts <50 cells/μL and a rapid drop in HIV RNA
D) Patients with stable HIV viral loads

Answer 43

Answer: C) Patients with CD4+ counts <50 cells/μL and a rapid drop in HIV RNA
Rationale: IRIS is most common in severely immunosuppressed patients who experience a rapid decrease in HIV RNA after starting ART.