Viral sequence analysis of HIV-positive women and their infected children: insight on the timing of infection and on the transmission network

Prior Exposure to Intimate Partner Violence Associated With Less HIV Testing Among Young Women

Low-income minority women are disproportionately represented among those living with HIV in the United States. They are also at risk for the SAVA (substance abuse, violence, and HIV/AIDS) syndemic issues. Women who have recently given birth are at high risk for substance use and intimate partner violence (IPV), and HIV testing is not routinely administered during the postpartum visit. We explored the relationship between substance use, IPV, and HIV testing among low-income young adult women attending Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), a federally supported nutrition program. A survey assessed substance use, relationships in particular with violence exposure, and HIV testing behavior in the past 6 months among a convenience sample of 100 women aged 18 to 30. The survey was conducted at several WIC offices in an urban setting in the Mid-Atlantic region between June and December 2015. Physical violence was the only IPV variable significantly associated (p = .022) with not being tested for HIV in the past 6 months, remaining significant even after adjusting for demographic and other significant variables (adjusted odds ratio [AOR] = 0.02; 95% confidence interval [CI] = [0.00, 0.41]). Women exposed to physical IPV or psychological IPV in the past year were significantly more likely to have ever used an illicit drug (physical IPV: 34% vs. 59%, p = .052; psychological IPV: 22% vs. 53%. p = .002). These findings between physical IPV and HIV testing history highlight the need to further understand how the context of violence affects HIV testing behaviors. Providing convenient, safe, and accessible HIV testing sites in spaces like WIC may increase HIV testing rates overall and specifically among women experiencing IPV.

Combining Viral Genetics and Statistical Modeling to Improve HIV-1 Time-of-infection Estimation towards Enhanced Vaccine Efficacy Assessment

Knowledge of the time of HIV-1 infection and the multiplicity of viruses that establish HIV-1 infection is crucial for the in-depth analysis of clinical prevention efficacy trial outcomes. Better estimation methods would improve the ability to characterize immunological and genetic sequence correlates of efficacy within preventive efficacy trials of HIV-1 vaccines and monoclonal antibodies. We developed new methods for infection timing and multiplicity estimation using maximum likelihood estimators that shift and scale (calibrate) estimates by fitting true infection times and founder virus multiplicities to a linear regression model with independent variables defined by data on HIV-1 sequences, viral load, diagnostics, and sequence alignment statistics. Using Poisson models of measured mutation counts and phylogenetic trees, we analyzed longitudinal HIV-1 sequence data together with diagnostic and viral load data from the RV217 and CAPRISA 002 acute HIV-1 infection cohort studies. We used leave-one-out cross validation to evaluate the prediction error of these calibrated estimators versus that of existing estimators and found that both infection time and founder multiplicity can be estimated with improved accuracy and precision by calibration. Calibration considerably improved all estimators of time since HIV-1 infection, in terms of reducing bias to near zero and reducing root mean squared error (RMSE) to 5-10 days for sequences collected 1-2 months after infection. The calibration of multiplicity assessments yielded strong improvements with accurate predictions (ROC-AUC above 0.85) in all cases. These results have not yet been validated on external data, and the best-fitting models are likely to be less robust than simpler models to variation in sequencing conditions. For all evaluated models, these results demonstrate the value of calibration for improved estimation of founder multiplicity and of time since HIV-1 infection.

Perspectives on HIV Testing Among WIC-Enrolled Postpartum Women: Implications for Intervention Development

Low-income minority women are disproportionately represented among those living with HIV in the U.S and also at-risk for substance abuse and intimate partner violence-collectively called the SAVA syndemic-which may impede HIV testing uptake. Views about HIV testing were assessed among women (ages 18-29) enrolled in a federally funded nutrition program for women, infants, and children (WIC) in a large Mid-Atlantic city. A survey (n = 80) and three focus groups were conducted in WIC offices located in neighborhoods with high HIV prevalence. Among this primarily minority sample, most would be interested in getting an HIV test if offered at WIC. Benefits included knowing one's HIV status, convenience, and accessible location, while transportation and peer/partner encouragement were enabling factors. Barriers included privacy concerns and intimate partner violence. Findings will be used to design an intervention to promote HIV testing among women who attend WIC and that proactively addresses reported barriers.