Even in rare cases when a person has undiagnosed acute HIV at the time they begin PrEP or post-exposure prophylaxis (PEP), they can usually still achieve durable viral suppression once on antiretroviral treatment (ART), researchers reported in the Journal of Acquired Immune Deficiency Syndromes. However, resistance mutations developed quickly in very few people.
Data came from the San Francisco City Clinic, which provides same-day, on-demand PrEP after a rapid point-of-care HIV test. A blood sample is then sent to a laboratory for pooled RNA testing, which is more sensitive for acute HIV, with results returned within five to 10 days.
Lab tests were positive for seven of the 1,758 people starting pre-exposure prophylaxis and six of the 2,242 people starting PEP at the clinic between 2011 and 2018, all of whom had a negative rapid HIV test at the time they commenced PrEP or PEP. All 13 participants who were found to have acute HIV on the day of PrEP/PEP start were linked to care; 12 of them started ART, and 11 achieved viral suppression.
No tenofovir-associated mutations were found in the 11 samples that could be genotyped, but the virus of three participants had emtricitabine-related mutations, which had developed during the seven to 12 days of biomedical HIV prevention after seroconversion. (Based on subsequent genotyping of stored blood samples, it was determined that these participants had wild-type virus when they started PrEP ). All three were virally suppressed within six months of starting HIV treatment.
All of the participants with acute HIV in this study were men who have sex with men (MSM) reporting multiple anal sex partners. Only one was symptomatic on PrEP start. Most had been diagnosed with a bacterial sexually transmitted infection (STI) during the prior year.
“Overall, our results offer reassurance that the benefits of same-day PrEP prescribing outweigh the risks associated with initiating PrEP in the setting of [acute HIV], provided systems are in place for early diagnosis and connection to HIV care,” study authors concluded. They also wrote that the findings could help PrEP programs in resource-limited settings prioritize pooled RNA testing, given the lower availability of HIV screening methods commonly used in higher-income areas.