CROI 2024 Abstract eBook

Abstract eBook

Oral Abstracts

205

Opt-Out HIV Testing in Emergency Departments Successfully Addresses Key Gaps in Testing Lisa Hamzah 1 , Kathryn Childs 2 , Ian S. Cormack 3 , Olubanke Davies 4 , Roddy Font 5 , Lewis Haddow 6 , Elizabeth Hamlyn 2 , Kathryn Harrop 7 , Rachel Hill-Tout 8 , Steven Kegg 9 , Iesha Lovatt 7 , Larissa Mulka 2 , Melanie Rosenvinge 9 , Lucy Wood 9 , for the South London HIV ED Opt Out Testing Group 1 St George's University Hospitals NHS Foundation Trust, London, UK, 2 King's College Hospital NHS Foundation Trust, London, UK, 3 Croydon Health Services NHS Trust, London, UK, 4 Epsom and St Helier University Hospitals NHS Trust, London, UK, 5 Guy’s and St Thomas’ NHS Foundation Trust, London, UK, 6 Kingston Hospital NHS Foundation Trust, London, UK, 7 South London Office for Specialised Services, London, UK, 8 NHS England, London, UK, 9 Lewisham and Greenwich NHS Trust, London, UK Background: 'Getting to zero' and ending new HIV transmissions by 2030 is a major focus for HIV prevention in the UK. To achieve this, national funding was provided to expand opt-out testing for HIV across all South London emergency departments (ED) from April 2022 for attendances aged over 16-18 years having a blood test for any reason. We describe new HIV diagnoses in South London during the first 12 months of testing and compare HIV prevalence and new diagnoses rates in ED to national published data. Methods: Demographic data were collated and summarised for all new HIV diagnoses across South London ED. Prevalence data were calculated, including previously known HIV diagnoses, overall and by region and compared to local published prevalence data. The project was registered as service evaluation. Results: Between April 2022 and March 2023, across 10 acute hospital EDs, there were 446881 eligible attendees and 335263 HIV tests performed. HIV test uptake increased from 61% in April 22 to 80% in March 2023. We identified 128 new HIV diagnoses: 65% male, 72% heterosexual, median age 43.5 years (range 16- 77), 55% black ethnicity, 84% within the lowest multiple deprivation deciles (1-5). 92% were engaged in care within median (IQR) 5 (2-13) days with median (IQR) baseline CD4 271.2 (79-385.3 cells/uL), mean (SD) viral load 5.0 (1.2) log copies/ml. 69% had a CD4<350 and 41% CD4<200 cells/uL. 75% overall, 64% with CD4<350 and 35% with CD4<200, did not report HIV indicator conditions at presentation to ED. 22% were subsequently diagnosed with an AIDS related illness. After median (IQR) 6.8 (3.8-9.9) months follow up, median CD4 was 350 (210-600) and 70% had an undetectable viral load. New diagnosis rates in the ED population exceeded the overall new diagnosis rates in London by almost 6-fold and 4-fold in South-East and South-West London respectively. In South East London, HIV prevalence in ED was higher than previous reported estimates across London (Table). Conclusion: ED HIV opt out testing was successful in achieving high rates of new diagnoses, in areas of high deprivation, with excellent linkage to care. Over two-thirds of diagnoses were late (CD4<350) and less than a quarter had indicator conditions at presentation. This intervention is a powerful tool to reach individuals who would not have otherwise been identified, reduce health inequalities and address key gaps in testing for groups such as heterosexual men, who may not attend traditional testing services such as antenatal and sexual health. Few Discordant HIV Ag/Ab and RNA Test Results Among Persons in a National Cohort of PrEP Users Weiming Zhu , Ya-Lin A. Huang, Kevin P. Delaney, Rupa Patel, Athena Kourtis, Karen W. Hoover Centers for Disease Control and Prevention, Atlanta, GA, USA Background: PrEP users can have ambiguous HIV test results for detection of primary infection. The CDC 2021 PrEP guidelines recommend HIV RNA testing for PrEP initiation and monitoring. We evaluated occurrence of discordant HIV test results in oral and long-acting cabotegravir (CAB-LA) PrEP users in a large real-world cohort of PrEP users. Methods: We analyzed the HealthVerity HIV cohort with linked longitudinal medical claims, antiretroviral prescriptions, and laboratory testing records. Our primary outcomes were discordant HIV Ag/Ab and RNA test results, new HIV diagnoses, and Long-acting Early Viral Inhibition (LEVI) cases among PrEP users. We used a validated algorithm and identified persons prescribed oral or injectable PrEP and extracted all their laboratory records. We defined a "combined test" as both Ag/Ab and RNA testing within 7 days. We analyzed all tests from 30 days before the first PrEP prescription through 30 days after

last prescription. Among persons with discordant results, we reviewed all their laboratory tests, diagnosis records, and ARV prescriptions. Results: Among 30 548 PrEP users, we identified 9090 combined tests in 5391 individuals; 8995 (99.0%) were same-day tests. HIV Ag/Ab and RNA results were concordant for 9070 (99.8%) tests with 18 dual positives (+) in 17 persons, and 9052 dual negatives (-) in 5374 persons. We identified 14 combined tests in 12 persons with Ag/Ab(-) and RNA(+) results, accounting for 0.15% of all combined tests. Review of records found 4 HIV diagnoses; 4 likely false positive RNA tests (with repeated dual (-) tests and follow-up >30 days); and 4 inconclusive results (insufficient follow-up) (Figure). Excluding inconclusive cases, RNA tests had a false positive rate (FPR) of 0.04% and a positive predictive value (PPV) for HIV infection of 84% among PrEP users. No LEVI cases were observed among 439 CAB-LA users. We also found 6 discordant tests in 4 patients with Ag/Ab(+) and RNA(-) results. Of these, one person had a likely false positive Ag/Ab test (FPR of 0.01%, PPV 94.4%), while 3 persons had insufficient follow-up. Conclusion: Discordant combined test results among PrEP users were rare and a third of discordant tests identified a new HIV diagnosis, accounting for 19% of all diagnosed HIV infections. Combined testing resulted in similar early HIV diagnoses rates and potential false positive NAT rates. The FPR of Ag/Ab testing was low. Further assessment of predictive values and cost-effectiveness of HIV RNA testing of PrEP users is warranted.

Oral Abstracts

206

207

Missed Opportunities to Prevent Congenital Syphilis in Antenatal PrEP Services in South Africa Dvora L Joseph Davey 1 , Aurelie Nelson 2 , Kalisha Bheemraj 2 , Alex de Voux 2 , Rufaro Mvududu 2 , Lisa Frigati 3 , Landon Myer 2 1 University of California Los Angeles, Los Angeles, CA, USA, 2 University of Cape Town, Cape Town, South Africa, 3 Tygerberg Hospital, Cape Town, South Africa Background: Pregnant women are a key population for HIV prevention through pre-exposure prophylaxis (PrEP) services and women at risk of HIV acquisition are also at risk of syphilitic infection. There is growing concern around congenital syphilis globally, yet there are few insights into the burden of syphilis in pregnant women on PrEP and their infants in Africa. Methods: We evaluated syphilis positivity and congenital syphilis in a cohort of pregnant women in Cape Town without HIV (>16 years) on oral PrEP in between March 2022 and December 2023. Per local standard of care, women were tested

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CROI 2024