CROI 2024: Global Epidemiology and Prevention of HIV and Other Sexually Transmitted Diseases.

At the 2024 Conference on Retroviruses and Opportunistic Infections (CROI), investigators presented updates on the global HIV epidemic, focusing on ongoing disparities by race/ethnicity in the US, the ongoing concentration of new infections among men who have sex with men (MSM) and transgender women in the Americas, and a shift to a greater total number of infections now in low versus high prevalence countries globally. HIV testing, the gateway to prevention and to treatment, has not fully rebounded from the substantial declines seen during the early COVID-19 pandemic in some settings, although innovative strategies including home testing and opt-out testing in clinical settings appear to be reaching populations in need of testing. Several investigators reported on the efficacy and effectiveness of doxycycline used as postexposure prophylaxis (doxy-PEP) to prevent bacterial sexual transmitted infections in MSM and transgender women in clinical trials and clinic settings; citywide rates of chlamydia and syphilis have decreased in San Francisco after the rollout of the first doxy-PEP guidelines in the US. Lack of doxy-PEP efficacy in cisgender women in Kenya appears due to low adherence in that trial. Rollout and persistence on oral HIV preexposure prophylaxis (PrEP) are associated with reduced seroincidence on a population and individual level. The rollout of long-acting injectable cabotegravir (CAB-LA) PrEP is proceeding slowly in the US. New, longer-acting oral and injectable agents are in development, with preclinical and early clinical trial data presented at CROI. Oral PrEP uptake among populations in sub-Saharan Africa remains low in most settings, suggesting the need for more options and more support; point-of-care tenofovir testing appear acceptable in various populations and may improve adherence and identify PrEP users needing more support. Choice of PrEP or PEP including CAB-LA combined with clinical support substantially increased biomedical prevention coverage in East Africa. Novel approaches to PrEP rollout, including delivery using mobile services and in nonclinical settings appear to show promise. HIV PEP continues to be underutilized.

Point-of-care urine tenofovir test predicts future HIV preexposure prophylaxis discontinuation among young users.

BACKGROUND: Young men who have sex with men and transgender women (YMSM/TGW) have disproportionately high HIV incidence and lower preexposure prophylaxis (PrEP) adherence. Point-of-care (POC) urine tenofovir (TFV) rapid assay (UTRA) testing permits real-time monitoring for nonadherence within clinical settings. We performed UTRA testing among PrEP users to examine the relationship between low PrEP adherence and future PrEP discontinuation, and the accuracy of POC testing compared to gold-standard liquid chromatography tandem mass spectrometry (LC/MS/MS). METHODS: YMSM/TGW participants ( n  = 100) were recruited during a daily PrEP visit. Logistic regression models analyzed the relationship between the primary predictor of urine POC assay results (cutoff 1,500 ng/ml) and the primary outcome of PrEP discontinuation, defined as no PrEP follow-up or prescription within 120 days. RESULTS: Overall, 19% of participants had low urine TFV and 21% discontinued PrEP, while 11% of participants self-reported low PrEP adherence (<4 pills per week), which was only 43% sensitive/84% specific in predicting low TFV levels and was not associated with PrEP discontinuation. Low urine TFV level predicted PrEP discontinuation [adjusted odds ratio (AOR) 6.1; 95% confidence interval (CI): 1.4-11; P  = 0.005] and was 71% sensitive/90% specific for discontinuation after 120 days. Compared to LC/MS/MS, UTRA testing had a 98% positive and 100% negative predictive value. CONCLUSIONS: In a sample of YMSM/TGW on daily PrEP, POC UTRA testing predicted PrEP discontinuation more accurately than self-reported adherence, with high predictive values compared to LC/MS/MS. UTRA testing may be a clinical tool for directing preventive interventions towards those likelier to discontinue PrEP despite ongoing HIV vulnerability.