Background:
Adolescent girls and young women (AGYW) account for 1 in 5 new HIV infections in sub–Saharan Africa and can greatly benefit from PrEP. While studies among AGYW show high oral PrEP uptake, early discontinuation is common. Objective adherence measures may enhance counselling and promote adherence, but are often costly, require specialized tests and require long turnaround times for spectrometry-based metrics. We evaluated a novel point-of-care urine tenofovir (TFV) assay, using antibody-based technology, to measure adherence and its alignment with self-reported adherence and HIV seroconversion among AGYW.
Methods:
From August 2022-July 2023, we enrolled an open label PrEP cohort of sexually active AGYW aged 16-30 years and interested in PrEP from 20 sites (15 in South Africa and 1 site each in Eswatini, Kenya, Malawi, Uganda, and Zambia). Participants attended study visits 1, 3 and 6 months after enrollment and were offered PrEP and adherence counselling at each visit. PrEP use was assessed via self-report and a qualitative lateral flow urine TFV assay, for which a predetermined threshold of >1500 ng/ml indicates TFV use in the past 4 days. Acceptability of urine TFV testing was assessed at Month 6 via questionnaire.
Results:
The INSIGHT cohort enrolled 3087 AGYW. At enrolment, 95.6% of participants-initiated PrEP. At months 1, 3, and 6, 95.7%, 94.4%, and 88.8% received PrEP refills and 77.5%, 79.6%, and 64.1% of those with urine tests had TFV detected in the urine assay respectively. The 3 main reasons for PrEP discontinuation were side effects, low risk perception, and peer influence. Self-reported good, very good, or excellent adherence was well aligned with positive results from the urine TFV test (OR=8.5, 95% CI 7.4-9.8). HIV incidence was 1.38/100 person-years (95% CI 0.97-2.08). At Month 6, 58.3% of women reported that a positive urine TFV result motivated them to take PrEP, 23.6% reported that the counsellor helped them identify ways to remember PrEP, and 21% reported that a negative urine test result was not surprising.
Conclusions:
Oral PrEP uptake was >95% among a multisite cohort African AGYW with almost 90% refilling PrEP at Month 6 and the majority (64-80%) had evidence of recent use, based on a novel urine TFV assay, which is higher PrEP adherence than in prior studies. Oral PrEP can be an effective PrEP option for African AGYW. Real time drug feedback using the urine TFV assay is acceptable and warrants further study to support PrEP adherence.