Best Recommendation: Take a Rapid HIV Test
The pharmacist should immediately recommend a rapid HIV test before dispensing PrEP, as fever, fatigue, and new-onset rash are classic symptoms of acute HIV infection, and initiating PrEP in someone with undiagnosed HIV could lead to viral resistance and inadequate treatment. 1, 2, 3
Clinical Reasoning
Why HIV Testing is Critical in This Scenario
Acute HIV infection presents with fever, fatigue, and rash in the context of recent high-risk exposure, which are precisely the symptoms this patient is exhibiting 2, 3
PrEP must never be initiated or continued in HIV-positive individuals because monotherapy with cabotegravir or dual therapy with tenofovir/emtricitabine does not constitute a complete treatment regimen and will lead to resistance mutations (particularly M184V and integrase resistance) 1, 3
The 2020 International Antiviral Society-USA guidelines explicitly state that a reactive rapid point-of-care HIV assay should be confirmed by combined antibody and antigen testing with subsequent HIV RNA confirmation 1
Appropriate Testing Algorithm
Start with a rapid HIV test immediately at the pharmacy or refer for immediate testing, as results are available within 1 hour and can be performed by non-licensed staff 1, 4
If the rapid test is reactive (positive), do not dispense PrEP and refer immediately for confirmatory combined antibody/antigen testing plus HIV RNA testing 1, 2
If the rapid test is negative but symptoms persist, HIV RNA testing should still be obtained because acute HIV infection can occur during the "window period" when antibody tests may be negative but the patient is infected and highly infectious 1, 2
Multiple rapid tests can be used for adjudication if discrepant results occur, rather than waiting for Western blot confirmation which causes unnecessary delays 1, 4
Why the Other Options Are Incorrect
Option A (cabotegravir/rilpivirine) and Option D (bictegravir/emtricitabine/tenofovir alafenamide) are both treatment regimens for established HIV infection, not appropriate for someone picking up PrEP who may have acute HIV infection 1. Starting treatment without confirming HIV status and obtaining baseline resistance testing would be premature.
Option C (HIV RNA and CD4 count) is more comprehensive testing but takes longer to result and is not the immediate first step 2. The rapid HIV test should be performed first, with RNA testing reserved for confirmation of reactive results or when acute infection is suspected despite negative antibody testing 1, 4.
Critical Pitfalls to Avoid
Never dispense PrEP without confirming HIV-negative status, especially when symptoms of acute HIV infection are present 2, 3
Do not assume symptoms are unrelated - the triad of fever, fatigue, and rash in someone seeking PrEP should immediately raise suspicion for acute HIV seroconversion 2, 3, 5
PrEP can delay or attenuate HIV seroconversion on diagnostic assays, making diagnosis more difficult if inadvertently started during acute infection 1
Resistance testing must be obtained if HIV is confirmed before initiating treatment, as the patient may have acquired resistant virus 1, 2
If HIV is Confirmed
Immediately transition to a complete antiretroviral treatment regimen - dolutegravir-based, bictegravir-based, or boosted darunavir-based regimens are recommended pending resistance testing results 1
Obtain genotypic resistance testing including integrase mutations before finalizing the treatment regimen 1, 2
Link the patient to ongoing HIV care with a specialist for comprehensive management 2, 5