ABSTRACT
Although post-exposure prophylaxis (PEP) is a powerful tool to abort HIV infection within 72 hours of exposure, blocking the establishment of chronic infection, follow-up metrics of this intervention are scarce. As antiretroviral use delays diagnosis biomarkers, the moment to perform serological evaluations must be considered this to avoid missed diagnosis opportunities. We assessed the return adherence after PEP dispensation in service in the Sao Paulo metropolitan area and reviewed the literature, both showing limited adherence to current protocols and leading to difficulties in diagnosing early HIV infection. The current proposed date for the first return after PEP is associated with low adherence and may have limited capability to detect antibodies if the infection is present. Guidelines should allow a longer time after PEP discontinuation along with message reminders to encourage adherence and avoid false negative results that can be detrimental both to the patient and to the community.