CROI 2020 Abstract eBook

Abstract eBook

Poster Abstracts

971 HEAT-INACTIVATED/LYOPHILIZED HIV VIRUS FOR USE IN PROFICIENCY TESTING PROGRAMS Raul Louzao 1 , Thomas M. Denny 1 , Heidi M. Register 1 , Wes Rountree 1 , Ambrosia Garcia 1 , Cassandra Porth 1 , Andrea Pappas 1 , Clare Morris 2 , Sarah Gilbert 2 , Bhavna M. Hora 1 , Feng Gao 1 1 Duke Human Vaccine Institute, Durham, NC, USA, 2 National Institute for Biological Standards and Control, South Mimms, United Kingdom Background: Proficiency testing (PT) for labs performing HIV viral load (VL) is critical to determining that acceptable patient monitoring standards are being established. Current PT programs utilize infectious material which requires a cold chain for shipping and local laboratory storage. We set out to develop QCMs to reduce the infectious risk of the QCM and overall cold chain requirements. Methods: A Clade C virus from the NIAID EQAPOL programwas heat inactivated and shown inability to replicate, as determined by VL and p24 Ag testing; then lyophilized at 50,000 copies/ml. Testing was performed at four storage temperatures (-20°C, 4°C, 23°C, 30°C) at seven time points. Linear modeling was performed to make descriptive statistics (e.g., estimation of means) and a descriptive evaluation of the means for storage temperatures and time points at the alpha 0.05 level. Results: The heat-inactivated non-lyophilized viral material showed a VL of 4.698 (-05.=4.198 and +0.5=5.198) Log 10 (copies/ml) during 12 months of repeat testing under -800C conditions. Shown below are VL results for the lyophilized material held at different storage conditions over time and then tested. We found statistical evidence of a 0.007 Log 10 increase per week of storage and that month 6 VL was higher than the average time point VL (see Figure 1). There was no statistical evidence of storage temperature differences. The model based means for storage temperatures range from 4.26 – 4.42 Log 10 copies/ml and the model based means for the time points range from 4.28 – 4. 49 Log 10 copies/ml. Displayed in Figure 1 below are the VL results for the lyophilized material held at different storage conditions over the various time points. The average VL is 4.38 with the standard acceptance criteria of +/- 0.5 Log 10 copies/ml at 3.88 and 4.88. Conclusion: These data we collected provides a proof of concept that the heat inactivated and lyophilized material remains stable and well within a the 0.5 Log 10 acceptance criterai at all temperature storage conditions for up to six months. Studies are underway to determine suitably of this material for use in quality assessment of drug mutation sequencing assays. Reducing cold chain requirements, shipping costs and infectious status of QCMs offers significant improvements to current PT approaches. Work supported by NIAID EQAPOL HHSN27220170061C.

Methods: Using Maxim HIV-1 LAg-Avidity EIA dried blood spot and plasma kits, we conducted HIV recency testing in a variety of routine service-provision contexts, namely: antenatal clinics providing PMTCT services in Siaya County, Kenya, routine HIV testing clinics in Nairobi, Kenya, and a national programme for female sex workers (FSW) in Zimbabwe. Our recency test results were interpreted as part of a Recent Infection Testing Algorithm (RITA), to which we included prior testing history, viral load and ART exposure. LAg results with a normalized optical density (ODn) of <1.5 and a viral load > 1000 copies/mL were classified as testing positive for recent infection. Results: Having tested participants for HIV, investigated HIV status and sought consent, in total 1,272 HIV positive women and men were tested for recent infection across the three pilots (see figure 1). Based on LAg test result alone, our crude recency percentages were 24.9% (106/426) in Siaya County, 11.3% (60/530) in Nairobi, and 15.6% (49/313) in Zimbabwe. Figure 1 highlights how combining our recency assay results with viral load greatly reduced the number of people classified as recent positive in all three settings. In Nairobi (ART metabolite testing) and Siaya County (linked clinic records) the number classified as recent positive was further reduced due to evidence of ART use (in Zimbabwe women with a history of a previous positive test or ART use were excluded). The final percentages of participants classified with a recent infection were 2.3% (10/426) among women in Siaya County, 8.7% (46/530) among men and women in Nairobi, and 10.5% (33/314) among FSW in Zimbabwe. Conclusion: We successfully identified recently acquired infections among persons diagnosed with HIV in real-world settings. Our recency percentages would have been substantially inflated without the inclusion of clinical information. In using recency assays to accurately distinguish recent from long-standing infection in routine settings, we highlight the importance of considering a person’s previous HIV test history, ART use, and viral load.

Poster Abstracts

972 IDENTIFYING RECENT HIV INFECTIONS IN REAL-WORLD SETTINGS IN KENYA AND ZIMBABWE Brian Rice 1 , Mariken M. De Wit 1 , Kathryn A. Risher 1 , Susie Welty 2 , Sungai T. Chabata 3 , Frances Cowan 4 , Georges Reniers 5 , Gary Murphy 6 , Jeffrey Eaton 7 , George Rutherford 2 , James R. Hargreaves 5 1 London School of Hygiene & Tropical Medicine, London, UK, 2 University of California San Francisco, San Francisco, CA, USA, 3 Centre for Sexual Health and HIV/AIDS Research Zimbabwe, Harare, Zimbabwe, 4 Liverpool School of Tropical Medicine, Liverpool, UK, 5 London School of Hygiene & Tropical Medicine, London, UK, 6 Public Health England, London, UK, 7 Imperial College London, London, UK Background: Distinguishing recently acquired infection from “long-standing” infection among persons newly diagnosed with HIV can help guide prevention programming. Focusing on the procedures required to accurately determine recent infection, we present the results of three pilots of HIV recency testing in Kenya and Zimbabwe.

973 STAGING OF HIV-1C INFECTION AMONG PATIENTS ON ART IN BOTSWANA USING PROVIRAL DNA Manon Ragonnet-Cronin 1 , Tanya Golubchik 2 , Sikhulile Moyo 3 , Christophe Fraser 2 , Max Essex 4 , Vlad Novitsky 4 , Erik Volz 1 , for the PANGEA Consortium 1 Imperial College London, London, UK, 2 University of Oxford, Oxford, UK, 3 Botswana Harvard AIDS Institute Partnership, Gabarone, Botswana, 4 Harvard T.H. Chan School of Public Health, Boston, MA, USA Background: HIV genetic diversity increases during infection and can be used to infer time since infection; however published analyses have included only antiretroviral treatment (ART) naïve individuals. Methods: Demographic and clinical information from HIV-1C-infected patients were collected within the Botswana Combination Prevention Project from 2013 to 2018. HIV genetic sequencing efforts have been intensified under

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