CROI 2017 Abstract e-Book

Abstract eBook

Oral Abstracts

35 NAMIBIA PILOTS SENTINEL POPULATION SURVEILLANCE OF HIV INCIDENCE AND VIRAL SUPRESSION Tuli Nakanyala 1 , Andrew D. Maher 2 , Nicholus Mutenda 1 , Karen M. Banda 2 , Anna Jonas 3 , Charity Ntema 4 , Ndapewa Hamunime 1 , David W. Lowrance 5 , Sadhna V. Patel 5 , Willi McFarland 2 1 Ministry of Hlth and Social Services, Windhoek, Namibia, 2 Univ of California San Francisco, San Francisco, CA, USA, 3 US CDC, Windhoek, Namibia, 4 Development Aid from People to People, Windhoek, Namibia, 5 CDC, Atlanta, GA, USA Background: Direct measures of HIV incidence and viral suppression (VS) are needed to assess population-level impact of prevention and treatment programs, particularly in an era of scaling-up efficacious interventions such as test and treat, male circumcision, and PrEP. However, gold standard longitudinal studies are scarce due to logistical complexity. We demonstrate the feasibility of using a community-based testing program to obtain sentinel, longitudinal estimates of HIV incidence and VS. Methods: Lay health workers (LHW) of a community based organization (Total Control of the Epidemic) working in high HIV prevalence regions of Namibia are assigned fields of ~375 households to provide home-based HIV testing and case management for clients who test positive. To this program, we added risk and prevention questions, collection of dried blood spots (DBS) and targeted one-year follow-up among adults (age > 14 years) in clusters of ~70 houses within 10 fields in Namibia’s Zambezi region. Fields included urban and rural areas and major cultural-linguistic groups. HIV incidence among baseline-negative adults was measured by repeat rapid testing. VS (< 1,000 copies/uL) among baseline-positive adults was measured in DBS using Abbot’s m2000 Realtime system. Results: From 12/2014-7/2015 in 1,004 households, we enrolled 2,218 adults (66.3% participation), among whom 1,339 (60.4%) were female, 815 (36.7%) age 15-24 years, 476 (21.5%) HIV positive (63.9% previously diagnosed) and 1,742 HIV negative. The effort entailed approximately two LHW per field. One year later [median (IQR) 431 (391-476) days follow-up], we performed repeat measurements among 93.2% and 88.9% of baseline-negative and positive adults, respectively. Cohort retention was significantly lower among men and baseline-positive adults. We observed 26 seroconversions in 1,970 person years (py) for a cluster-adjusted HIV incidence of 1.32 /100 py (95% CI 0.90-1.94). Cluster- adjusted VS at follow-up was 70.5% (95% CI: 61.5-79.5) among baseline-positive adults. Conclusion: We field tested an efficient method to obtain gold standard population-level measures of HIV incidence and VS in Namibia’s highest prevalence region. Differences in enrollment and retention suggest some biases to our approach. Nonetheless, the method, which utilizes existing community-based programs common to high prevalence areas of sub-Saharan Africa, can establish a system of sentinel cohorts that track changes in HIV incidence, VS and the impact of national responses to HIV. 36 SOCIAL NETWORKS AND HIV PREVALENCE IN KENYA IN THE SEARCH STUDY Wenjing Zheng 1 , Norton Sang 2 , Gabriel Chamie 3 , Laura B. Balzer 4 , Craig Cohen 3 , Tamara D. Clark 3 , Edwin D. Charlebois 3 , Moses R. Kamya 5 , Diane V. Havlir 3 , Maya L. Petersen 1 1 Univ of California Berkeley, Berkeley, CA, USA, 2 Kenya Med Rsr Inst, Nairobi, Kenya, 3 Univ of California San Francisco, San Francisco, CA, USA, 4 Harvard Univ, Boston, MA, USA, 5 Makerere Univ Coll of Hlth Scis, Kampala, Uganda

Oral Abstracts

Background: Social network information is more accessible than sexual network information, and may capture HIV transmission risk. Social networks may also reveal the formation of peer relationships between HIV+ individuals, which are important for treatment support. To investigate the potential for social networks to capture these dynamics, we linked named social contacts to population-wide baseline HIV testing data from Kenyan communities in the intervention arm of the SEARCH HIV Test and Treat Study (NCT01864603). Methods: During a census enumeration, 15,028 adult (age ≥15) residents of 3 communities named up to 6 friends in each of five social domains (health, money, emotional, food, and free time); 85% of residents were tested for HIV. Named contacts outside the household were matched to enumerated residents to construct community-wide social networks (Figure). Targeted maximum likelihood was used to estimate the relative risk of HIV associated with exposure to an HIV+ cross-gender or same-gender contact, adjusting for demographics, circumcision, alcohol use, contraception, mental health, work productivity, mobility and household wealth. Confidence intervals were adjusted for multiple comparisons across social domains. Results: HIV prevalence was 16%; 12% in all men, 19.5% in all women; 1% in young (<25) men, and 9.8% in young women. Men with an HIV+ female contact in any domain were at increased risk of HIV (aRR:1.5; 95%CI:1.1,2.0). Women with an HIV+male contact in any domain (aRR:1.4; 95%CI:1.1,1.8) or in the emotional domain (aRR:1.8; 95%CI:1.2,2.7) were at increased risk of HIV. Women’s increased risk was amplified if the HIV+male contact was >10 years older (aRR:1.6; 95%CI:1.1,2.5). Among young women, higher risk was associated with having an older HIV+ man in the free time (aRR:7.9; 95%CI:3.2,19.4), food (aRR:4.1; 95%CI:1.4,11.7), health (aRR:3.5; 95%CI:1.2,10.1), or any domain (aRR:3.4; 95%CI:1.6,7.1). Women with an HIV+ female contact in the health domain (aRR:1.6; 95%CI:1.2,2.1) were also more likely to be HIV+.

Conclusion: In this cross-sectional analysis of social network predictors of HIV risk in rural Kenya, exposure to HIV+ contacts within easily assessed social networks significantly predicted HIV risk and supported both known sexual transmission dynamics, such as those between young women and older men, and HIV+ peer relationships. These data may be useful for designing prevention and treatment support interventions for at risk populations. 37 HIGH RATE OF DISEASE PROGRESSION IN UNTREATED HIV-2 INFECTION Joakim Esbjörnsson 1 , Fredrik Månsson 2 , Anders Kvist 3 , Zacarias J. da Silva 4 , Jacob Lindman 3 , Angelica Palm 3 , Marianne Jansson 3 , Patrik Medstrand 3 , Hans Norrgren 3 , for the SWEGUB CORE Group 1 Univ of Oxford, Oxford, UK, 2 Lund Univ, Malmö, Sweden, 3 Lund Univ, Lund, Sweden, 4 LNSP, Bissau, Guinea-Bissau Background: Compared with HIV-1, HIV-2 is considered to be more benign and without severe pathogenic consequences throughout the disease course for the majority of infected individuals. However, conclusive survival data from cohorts with long follow-up and estimated time of infection is lacking. Methods: We followed 312 participants infected with HIV-1 or HIV-2 after enrollment in a cohort from Guinea-Bissau with 23 years of follow-up, according to the time from infection to AIDS or HIV-related mortality, and measures of T-cell dynamics. Weibull distributions were fitted to the survival data to assess the hypothesis of heterogeneous disease courses among HIV-2 infected individuals. Results: The median times to AIDS and mortality were 14.3 years (confidence interval [CI], 10.7-18.0) and 15.6 years (CI, 12.0-19.2) for HIV-2 infected participants, and 6.2 years (CI, 5.4-7.1) and 8.2 years (CI, 7.6-8.8) for HIV-1 infected individuals (p<0.001 for both comparisons, Log rank test). The Weibull analysis showed that HIV-2 infected individuals followed a uniform disease trajectory similar to HIV-1 infected individuals, but at a 53% lower acceleration rate. The proportion of HIV-2 infected individuals under risk at the end of follow-up was 17.5%, further supporting that the majority of HIV-2 infected individuals will progress to AIDS and HIV-related mortality if followed long enough. Linear mixed model analyses of T-cell dynamics showed both higher levels of CD4+ T-cell counts early after infection (p<0.001, Likelihood Ratio Test [LRT]) and slower decline rates among

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CROI 2017