CROI 2015 Program and Abstracts

Abstract Listing

Poster Abstracts

(yes=27.1/100 person-years [p-yrs] vs no=6.9/100 p-yrs; adjusted hazard ratio [aHR] 3.7, 95% CI 1.5, 9.3) and younger age trended toward an association (age <25 years=14.6/100 p-yrs vs. ≥ 25 years=7.6/100 p-yrs; aHR 2.0, 95% CI 0.8, 4.9). Having any curable STI in VOICE (CT, GC, or TV) was associated with incident TV (yes=16.5/100 p-yrs vs. no=4.2/100 p-yrs; aHR 5.6 95% CI 1.7, 18.4). No factors were associated with GC during follow-up. Results were similar in sensitivity analyses that excluded participants with the STI of interest at enrollment from each analysis.

Prevalence and incidence of curable STIs among HIV-infected South African women Conclusions: Curable STI incidence was high among South African women recently infected with HIV, especially among women who had a recent STI. New strategies for STI prevention counseling, screening, and treatment of women and their partners are needed to reduce the burden of curable STIs among recently HIV-infected women in this region. 1034 Population Mobility, Sexual Behavior and Risk of HIV Infection in Sub-Saharan Africa Laurence Palk ; Sally Blower On behalf of the Center for Biomedical Modeling David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA, US Background: Studies in Sub-Saharan Africa have shown an association between increased mobility and increased levels of sexual behavior, and/or risk of HIV infection. However, these studies have been conducted in countries with low/moderate HIV epidemics. Here we assess the potential impact of mobility on the high-prevalence epidemic in Lesotho, where 27% of women and 18% of men are infected with HIV. Methods: We analyzed linked demographic, behavioral and HIV infection data from the 2009 Demographic and Health Survey of Lesotho. The response rate was 98% for women, 95% for men. Further, 94% of eligible women and 88% of eligible men were tested for HIV. We quantitatively assessed the mobility of the population. We used a multivariate analysis to determine whether there is an association between mobility and increased levels of sexual behavior and/or risk of HIV infection. Results: We found that the population of Lesotho is highly mobile: 30% of women and 32% of men made one to four trips in the last year, 18% of women and 21% of men made five or more. Among those who travelled 37% of women and 39% of men were away for at least a month. Individuals who travelled were older than those who did not travel. They were also more likely to be married, employed, live in urban areas and have a higher level of education. In addition they were more likely to have had multiple partners in the last year; odds increased with frequency of travel, see table. Those who made five or more trips were almost twice as likely to have had two or more partners than those who did not travel. Individuals who travelled were also more likely to have concurrent partners than those who did not; odds increased with frequency of travel, see table. However, men who travelled were not more likely to have paid for sex than men who did not travel. Notably, only men who made five or more trips had an increased risk of HIV infection, see table. However, men who traveled infrequently (made one to four trips in the last year), and women who traveled (regardless of the number of trips) did not have an increased risk in comparison with individuals who did not travel. Table: Adjusted odds ratios (aOR) and confidence intervals (CI) of HIV infection and sexual risk behavior. Odds ratios are calculated adjusting for age, employment status, marital status and education. Stars denote the significance according to the following P-values: *** P <0.001, ** 0.001 ≤ P<0.01, * 0.01 ≤ P<0.05. Concurrent partnerships are calculated amongst those who had sex in the last 12 months. Conclusions: Population mobility needs to be considered when developing HIV prevention programs. Further, it is essential to target highly mobile men because they may disproportionally contribute to transmission. In Lesotho, and other countries with high levels of mobility (e.g., Zimbabwe, Cameroon and Kenya), it may be more difficult to control HIV epidemics than currently appears. 1035 HIV Transmission Linkage Among Seroconverting Partners in HIV-Discordant Relationships in Kenya Bhavna H. Chohan 1 ; Brandon L. Guthrie 2 ; Brian Khasimwa 4 ; Stephanie Rainwater 3 ; Barbara Lohman-Payne 2 ; Rose Bosire 2 ; Romel D. Mackelprang 2 ; Julie M. Overbaugh 3 ; Carey Farquhar 2 1 Kenya Medical Research Institute, Nairobi, Kenya; 2 University of Washington, Seattle, WA, US; 3 Fred Hutchinson Cancer Research Center, University of Washington, Seattle, WA, US; 4 University of Nairobi, Nairobi, Kenya Background: A large proportion of HIV-1 transmissions occur in the context of stable, HIV-discordant relationships. Understanding the distribution of infections that originate fromwithin the current partnership (linked) versus from an outside sexual relation (unlinked) is relevant to prevention interventions. We obtained viral sequences from newly HIV-1 infected individuals and their HIV-infected partners at seroconversion to determine the linkage of viral transmissions. Methods: A cohort of heterosexual HIV-serodiscordant couples in Nairobi, Kenya were followed to identify HIV-1 transmission events. HIV-1 envelope sequences were amplified and sequenced from peripheral blood mononuclear cells obtained from both partners at HIV sereconversion. Phylogenetic trees of viral sequences were constructed using the GTR Substitution Model in BEAST and pairwise genetic distances in PAUP* to assess genetic relationships and determine whether the new infection was linked to the study partner. Seroconversion risk was assessed by Cox proportional hazards regression. Demographic and behavioral factors were compared between the unlinked versus linked transmissions using Chi-square tests student’s t-tests. Results: A total of 12 incident HIV-1 infections occurred in a cohort of 458 HIV-1 serodiscordant couples (1.5/100 person-years). Phylogenetic analysis identified 8 (67%) incident infections as linked transmissions and 4 (33%) as unlinked. Viruses from the linked transmission pairs were closely related and formed monophyletic clusters on a single node in the phylogenetic trees (mean genetic pairwise distance 3.4%; range 0.12-6.23%). The HIV-1 env sequences from the unlinked transmission were distantly related and formed polyphyletic clusters (mean genetic distance 13.7%; range 9.22-17.51%). All 4 unlinked HIV transmissions were in males, compared to only 2 (25%) of 8 linked transmissions

Poster Abstracts

607

CROI 2015