Background: International guidelines recommend HIV post exposure prophylaxis following sexual exposure (PEPSE) to prevent HIV infection. However, methods to screen for infection prior to initiating PEPSE are less clear, with little or no guidance for management of acute HIV diagnosed during PEPSE. We present a case series of individuals diagnosed HIV+ whilst on PEPSE.
Methods: Cases definitions include the following criteria:
1. PEPSE failure: negative point of care test (POCT) and 4th generation laboratory test at PEP start, with HIV diagnosed during PEP or in follow up period
2. Acute HIV infection at PEPSE initiation: negative POCT but subsequent reactive 4th generation test at PEP startResults: 18 patients identified; 17 male/1 female, mean age 34 years. 11/18 (67%) had a previous negative HIV test using laboratory Abbott Ab/Ag tests, 1/18 POCT, in the preceding 12 months to accessing PEP. 18/18 were prescribed NRTI + bPI, 16 of these in line with current UK guidelines.
From data available on 16 (2 not diagnosed at our trusts), HIV diagnoses were subsequently made using laboratory Ab/Ag test in 14/16, POCT in 1 and HIV RNA in 1. 1/18 tested negative by POCT and Ab/Ag lab tests at PEP start, subsequently tested HIV+ with a weakly reactive p24 antigen and positive HIV-RNA on laboratory testing 19 days after completing a 28 day PEP course. The remaining 17 patients initiated PEP based on a negative POCT or recent negative HIV antibody test but were subsequently diagnosed HIV+ using lab tests . Therefore 17/18 (94%) of patients were already HIV+ at PEP initiation.
Of those diagnosed HIV+ whilst still on PEP, 11/16 (68%) opted to continue ART. A decision was made to stop PEP in 5 patients (mean number of days on PEP; 10); this advice was not influenced by CD4 or HIV RNA. 5/11 switched PEP regimes to first line ART. 2/18 had drug resistance: K103N, T215D at diagnosis.
Conclusions: Patients presenting for PEP after sexual exposure are high-risk individuals who may be seroconverting at the time of presentation. It is essential that if a POCT is used at screening, this is accompanied by a 4th generation test as near to initiation as possible, and that dual therapy (as still recommended in some guidelines) must be avoided in this setting.
Acute HIV diagnosis whilst on PEP represents an opportunity for early ART with reduction of viral reservoirs and improvements in CD4 outcome. In the absence of specific data to inform best practice, we recommend continued ART until urgent review by an HIV specialist.