CROI 2019 Abstract eBook

Abstract eBook

Poster Abstracts

923 HIV SEROLOGICALLY INDETERMINATE INDIVIDUALS: FUTURE HIV STATUS AND RISK FACTORS George Mwinnyaa 1 , Mary K. Grabowski 2 , Ronald H. Gray 3 , Maria Wawer 3 , Larry W. Chang 2 , Joseph Ssekasanvu 3 , Joseph Kagaayi 4 , Godfrey Kigozi 4 , Sarah Kalibbala 4 , Ronald M. Galiwango 4 , Anthony Ndyanabo 4 , David Serwadda 5 , Thomas C. Quinn 1 , Steven J. Reynolds 1 , Oliver Laeyendecker 1 1 NIAID, Baltimore, MD, USA, 2 Johns Hopkins University School of Medicine, Baltimore, MD, USA, 3 Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA, 4 Rakai Health Sciences Program, Kalisizo, Uganda, 5 Makerere University, Kampala, Uganda Background: Indeterminate HIV test results, where two EIA results contradict each other, are common, but little is known about longitudinal patterns in HIV testing results among those with indeterminate results or their sociodemographic and behavioral correlates. We assessed future HIV serological outcomes for people with indeterminate results and associated factors in Rakai, Uganda Methods: 44,926 adults aged 15-49 years (total of 136,414 person-visits) from 1994 to 2011 in the Rakai Community Cohort Study were assessed. Modified Poisson regression models with generalized estimating equations were used to assess prevalence ratios (PRs) of subsequent HIV serological outcomes for participants with 2 or more visits (n=27,119) and factors associated with HIV serologically indeterminate results. Lorelograms were used to assess the within person correlation of indeterminate results over multiple study vi Results: The overall prevalence of HIV serologically indeterminate results was 4.6%. Participants with an indeterminate HIV test result were more likely to have an indeterminate result at subsequent visits compared to those with negative results (PR 11.96, 95% CI 11.41,12.53). Subjects with an indeterminate result were twice as likely to have a subsequent HIV positive result compared to those with a negative result (PR 2.28, 95% CI 1.96, 2.65). The within-person correlation of indeterminate results was autoregressive with individuals being more likely to test indeterminate closer in time to a prior indeterminate result. In regression analyses, indeterminate results were less likely to occur in women than in men (adjPR 0.77, 95% CI 0.71,0.83), in unmarried participants than in married participants (AdjPR 0.92, 95% CI 0.85,1.00), and in individuals with an education relative to those with no education (primary education: adjPR 0.88, 95% CI 0.78,1.00; secondary education; adjPR 0.79, 95% CI 0.68,0.91; post- secondary education; adjPR 0.73, 95% CI 0.57,0.93). Occupation, number of sex partners, religion and malaria status, were not associated with indeterminate results. Conclusion: Individuals with HIV indeterminate serological results were more likely to have future indeterminate and positive HIV results compared to those with negative results. Gender, marital status and education were independently associated with indeterminate serostatus. Individuals with indeterminate results should be targeted for follow-up testing as they are more likely to eventually test positive. 924 ROUTINE TESTING OF NONPATIENTS INCREASES HIV DIAGNOSIS IN WESTERN KENYA Rachael Joseph 1 , Paul K. Musingila 1 , Fredrick Miruka 1 , Stella Wanjohi 2 , Caroline O. Dande 3 , Polycarp Musee 4 , Dickens Onyango 5 , Gordon Okomo 6 , Samuel Omondi 7 , Emily C. Zielinski-Gutierrez 8 , Lucy Ng’ang’a 8 , Hellen Muttai 8 , Kevin M. De Cock 8 1 US CDC Kisumu, Kisumu, Kenya, 2 Centre for Health Solutions, Nairob, Kenya, 3 Centre for Health Solutions, Siaya, Kenya, 4 Elizabeth Glaser Pediatric AIDS Foundation, Homa Bay, Kenya, 5 Kisumu County Department of Health, Kisumu, Kenya, 6 Homa Bay County Department of Health, Homa Bay, Kenya, 7 Siaya County Department of Health, Siaya, Kenya, 8 US CDC Nairobi, Nairobi, Kenya Background: An estimated 150,000 (36%) persons living with HIV (PLHIV) in Homa Bay, Siaya, and Kisumu counties in western Kenya do not know their HIV status. In 2016, health facilities in these 3 counties implemented universal access to provider-initiated HIV testing and counseling services for both patients and non-patients accompanying patients to the outpatient department (OPD). We assessed HIV testing outcomes among patient and non-patient clients at several health facilities. Methods: We retrospectively analyzed routinely collected program data from 7 high-volume (>1,000 monthly OPD visits) health facilities in western Kenya. Data from patient and non-patient clients aged 15 years or older who received HIV testing services in OPDs (March–December 2017) were included. We conducted a descriptive analysis of client characteristics and HIV testing

922 HIV-1/2 DIFFERENTIATION IN THE US HIV TESTING ALGORITHM: HIGH BURDEN, LOW YIELD Anne H. Peruski , Laura Wesolowski, Kevin P. Delaney, Pollyanna R. Chavez, S. Michele Owen, Timothy Granade, Vickie Sullivan, WilliamM. Switzer, John T. Brooks, M. Patricia Joyce CDC, Atlanta, GA, USA Background: Since 2014, the national algorithm for laboratory-based HIV testing has recommended a supplemental HIV-1/2 differentiation test as the second test for confirmatory HIV diagnosis to resolve issues of HIV-2 antibody cross-reactivity with HIV-1 specific tests and to identify potential HIV-2 infections. HIV-1/2 differentiation testing requires laboratories to acquire specialized equipment or to send out specimens to commercial reference labs for additional testing, which may increase cost and delay confirmation of infection. We therefore sought to assess the burden and yield of HIV-2 testing in the United States under the current algorithm, particularly regarding the HIV-1/2 differentiation test. Methods: We used results reported to the U.S. National HIV Surveillance System during 2012-2016. HIV-2 mono-infection was defined as confirmed HIV-2 infection (e.g., positive HIV-2 RNA or DNA) in the absence of HIV-1 infection. Dual infection was defined as confirmed infection with HIV-1 (e.g., positive HIV-1 RNA or DNA) and HIV-2. Infections were defined as not confirmed for HIV-2 if an HIV-2 antibody result was positive but there was no confirmatory lab test reported. Results: Among 202,536 HIV diagnoses reported during 2012-2016, the annual number of persons tested with an HIV-1/2 differentiation assay increased from 9,785 (23.5%) in 2012 to 32,126 (80.6%) in 2016. The annual number of confirmed HIV-2 mono-infections ranged from two to five. Four total dual infections were identified. Possible HIV-2 infection could not be confirmed for 115 (0.06%) persons. Conclusion: During 2012-2016, use of HIV-1/2 differentiation tests increased substantially, which is consistent with the implementation of the new guidelines for the U.S. HIV testing algorithm. Despite increased testing, the number of confirmed and possible (i.e., undetermined) HIV-2 diagnoses remained extremely low. In light of the substantial burden yet low yield of HIV-1/2 serological differentiation in the national testing algorithm, it’s prioritization as the second step in confirmation of HIV infection merits reconsideration.

Poster Abstracts

CROI 2019 361