A case of undisclosed prior exposure to antiretroviral therapy (ART) and early virologic failure that improved on a pre-emptive third-line ART regimen.

Introduction: The test and treat strategy recommends starting ART on the same day of diagnosis; yet, in Namibia neither baseline viral load (VL) nor genotypic resistance testing (GRT) are recommended prior to ART initiation. However, some clients return to care having defaulted ART and undergo HIV testing as "new" clients without disclosing their previous exposure, which predisposes them to primary virologic failure. Case report: A 53-year-old man tested HIV positive in 2019 without disclosing his prior exposure to ART from 2010-2015 and who stopped medication from 2015-2019 due to religious advice. He was thus initiated of first-line ART on the same day of his new diagnosis with a nadir CD4 count of 102 cells/mm3. He had a negative cryptococcal serum antigen, a normal creatinine clearance but with hepatitis B coinfection. He presented later with a primary virologic failure (VL >1000 copies/mL) and severe immunosuppression. The in-depth discussion revealed previous exposure to ART. He consequently benefited from a presumptive third-line ART that suppressed his VL while a GRT was being processed which later confirmed ART resistance. Conclusions: In poor resource settings where GRT is not performed regularly, undisclosed exposure to ART might lead to subtherapeutic treatment and primary virologic failure. In such patients where primary virologic failure is suspected despite good adherence, presumptive third-line ART can be considered in severely immunocompromised patients while waiting for GRT. GERMS.