Pre-exposure prophylaxis for HIV prevention: how to predict success

Use of antiretroviral drugs to prevent sexual transmission of HIV-1 has been a critical priority since their development. In the past 2 years results from seven important prevention trials have been reported (table). One of the trials, HPTN 052, showed nearly complete prevention of HIV transmission when viraemia was suppressed. The other studies focused on antiretroviral agents for pre-exposure prophylaxis: two used 1% tenofovir gel (CAPRISA 004 and VOICE), four used oral tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) in combination (iPrEX, TDF2, Partners in Prevention [PIP], and Fem-PrEP), and two used oral TDF alone (VOICE and PIP). Somewhat confusingly, the findings of these studies have led to reports both of successful prevention of HIV infection (CAPRISA 004, iPrEx, TDF2, and PIP) and of futility (VOICE and Fem-PrEP)

Postpartum HIV care continuum outcomes in the southeastern USA

The aim of this study was to evaluate postpartum HIV care outcomes.Design:A prospective clinical cohort of women with HIV and a live birth at the University of North Carolina, 1996-2014.Methods:We estimated two stages of the HIV care continuum in the first 24 months postpartum: care retention (at least two visits per year, ≥90 days apart) and viral suppression (HIV RNA<400copies/ml). Multivariable models were fit using logistic regression.Results:Among 1416 women, 141 experienced a live birth at a median age of 28 years, with 74% virally suppressed at delivery. Among all women, 48% were retained in care and 25% maintained viral suppression for the first 24 months postpartum. Among women with available HIV RNA measures, 42% were suppressed at 24 months. HIV care retention estimates were stable across calendar years, but viral suppression rates at 24 months postpartum, among women with available HIV RNA measures, increased from 33 to 67% from 1996-2001 to 2009-2014 (P=0.04). Being at least 30 years old was positively, and receiving less than 12 weeks of antenatal antiretroviral therapy was negatively, associated with HIV care retention at 24 months postpartum [adjusted odds ratio (AOR): 2.41, 95% confidence interval (95% CI): 1.09-5.29 and AOR: 0.27, 95% CI: 0.08-0.86]. Older maternal age and viral suppression at delivery were both positively associated with virologic suppression at 24 months postpartum (AOR: 2.52, CI: 1.02-6.22, and AOR: 6.42 CI: 1.29-31.97, respectively).Conclusion:HIV care continuum outcomes decrease substantially postpartum, with younger women and those with less antenatal HIV care less likely to successfully remain engaged in HIV care following childbirth

Highly-parallelized simulation of a pixelated LArTPC on a GPU

The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype