A 32-year-old man comes to the clinic to establish care after recently testing positive fo… — USMLE Step 2 CK

A $32$ -year-old man comes to the clinic to establish care after recently testing positive for human immunodeficiency virus (HIV). He is currently asymptomatic and has no history of opportunistic infections. Vital signs are within normal limits. Physical examination reveals no lymphadenopathy, oral thrush, or skin lesions. Laboratory evaluation shows a CD4 T-lymphocyte count of $38/\mu\text{L}$ and an HIV RNA viral load of $280,000$ copies/mL. Serologic testing is positive for *Toxoplasma gondii* IgG antibodies. An interferon-gamma release assay is negative. An antiretroviral therapy (ART) regimen consisting of bictegravir, emtricitabine, and tenofovir alafenamide is initiated today. In addition to ART, which of the following is the most appropriate prophylactic antimicrobial regimen for this patient?

A
Trimethoprim-sulfamethoxazole and azithromycin
B
Azithromycin only
Trimethoprim-sulfamethoxazole onlyCevap
D
Trimethoprim-sulfamethoxazole and fluconazole
E
No prophylactic antimicrobials are indicated

Cevap

Trimethoprim-sulfamethoxazole only

The correct answer provides targeted prophylaxis for the exact pathogens this patient is at risk for without inappropriately prescribing unneeded antimicrobials. A CD4 count

< 200/\mu\text{L}

necessitates prophylaxis against *Pneumocystis jirovecii* pneumonia, and a count

< 100/\mu\text{L}

combined with positive IgG antibodies requires prophylaxis against *Toxoplasma gondii*. Trimethoprim-sulfamethoxazole provides highly effective coverage for both. Although the CD4 count is

< 50/\mu\text{L}

, primary prophylaxis for *Mycobacterium avium* complex (MAC) is no longer recommended for patients who are immediately starting antiretroviral therapy.

Adım Adım Çözüm

Analyze the patient's CD4 count and serologic status.

The CD4 count is

38/\mu\text{L}

(which is

< 200/\mu\text{L}

and

< 100/\mu\text{L}

) and Toxoplasma IgG is positive.

To identify which opportunistic pathogens the patient is currently at high risk for acquiring.

Identify the required primary prophylaxis regimens.

Prophylaxis is urgently required for Pneumocystis jirovecii (CD4

< 200/\mu\text{L}

) and Toxoplasma gondii (CD4

< 100/\mu\text{L}

with positive IgG). Trimethoprim-sulfamethoxazole effectively covers both.

To select the appropriate evidence-based antimicrobial agent.

Determine if Mycobacterium avium complex (MAC) prophylaxis is needed.

MAC prophylaxis (such as azithromycin) is not indicated because the patient is initiating fully suppressive antiretroviral therapy (ART) today.

Contemporary guidelines have removed the recommendation for MAC prophylaxis in patients starting ART, even when the CD4 count is

< 50/\mu\text{L}

Anahtar Kavram

In patients with HIV, primary prophylaxis for Mycobacterium avium complex (MAC) is no longer recommended if antiretroviral therapy is initiated immediately, but prophylaxis for Pneumocystis jirovecii and Toxoplasma gondii is still required based on CD4 thresholds.

Soru

Cevap

Adım Adım Çözüm

Anahtar Kavram

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