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Introduction: Oral preexposure prophylaxis (PrEP) in the form of tenofovir-disoproxil-fumarate/emtricitabine is being implemented in selected sites in South Africa. Addressing outstanding questions on PrEP cost-effectiveness can inform further implementation., Methods: We calibrated an individual-based model to KwaZulu-Natal to predict the impact and cost-effectiveness of PrEP, with use concentrated in periods of condomless sex, accounting for effects on drug resistance. We consider (1) PrEP availability for adolescent girls and young women aged 15-24 years and female sex workers, and (2) availability for everyone aged 15-64 years. Our primary analysis represents a level of PrEP use hypothesized to be attainable by future PrEP programs., Results: In the context of PrEP use in adults aged 15-64 years, there was a predicted 33% reduction in incidence and 36% reduction in women aged 15-24 years. PrEP was cost-effective, including in a range of sensitivity analyses, although with substantially reduced (cost) effectiveness under a policy of ART initiation with efavirenz- rather than dolutegravir-based regimens due to PrEP undermining ART effectiveness by increasing HIV drug resistance., Conclusions: PrEP use concentrated during time periods of condomless sex has the potential to substantively impact HIV incidence and be cost-effective., (© The Author(s) 2019. Published by Oxford University Press for the Infectious Diseases Society of America.)

To inform the level of attention to be given by antiretroviral therapy (ART) programs to HIV drug resistance (HIVDR), we used an individual-level model to estimate its impact on future AIDS deaths, HIV incidence, and ART program costs in sub-Saharan Africa (SSA) for a range of program situations. We applied this to SSA through the Spectrum-Goals model. In a situation in which current levels of pretreatment HIVDR are over 10% (mean, 15%), 16% of AIDS deaths (890 000 deaths), 9% of new infections (450 000), and 8% ($6.5 billion) of ART program costs in SSA in 2016-2030 will be attributable to HIVDR., (© The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.)

Background: It is unknown what properties would be required to make an intervention in low income countries that can eradicate or control human immunodeficiency virus (HIV) without antiretroviral therapy (ART) cost-effective., Methods: We used a model of HIV and ART to investigate the effect of introducing an ART-free viral suppression intervention in 2022 using Zimbabwe as an example country. We assumed that the intervention (cost: $500) would be accessible for 90% of the population, be given to those receiving effective ART, have sufficient efficacy to allow ART interruption in 95%, with a rate of viral rebound of 5% per year in the first 3 months, and a 50% decline in rate with each successive year., Results: An ART-free viral suppression intervention with these properties would result in >0.53 million disability-adjusted-life-years averted over 2022-2042, with a reduction in HIV program costs of $300 million (8.7% saving). An intervention of this efficacy costing anything up to $1400 is likely to be cost-effective in this setting., Conclusions: Interventions aimed at curing HIV infection have the potential to improve overall disease burden and to reduce costs. Given the effectiveness and cost of ART, such interventions would have to be inexpensive and highly effective., (© The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America.)

Background: Studies have demonstrated that self-testing for human immunodeficiency virus (HIV) is highly acceptable among individuals and could allow cost savings, compared with provider-delivered HIV testing and counseling (PHTC), although the longer-term population-level effects are uncertain. We evaluated the cost-effectiveness of introducing self-testing in 2015 over a 20-year time frame in a country such as Zimbabwe., Methods: The HIV synthesis model was used. Two scenarios were considered. In the reference scenario, self-testing is not available, and the rate of first-time and repeat PHTC is assumed to increase from 2015 onward, in line with past trends. In the intervention scenario, self-testing is introduced at a unit cost of $3., Results: We predict that the introduction of self-testing would lead to modest savings in healthcare costs of $75 million, while averting around 7000 disability-adjusted life-years over 20 years. Findings were robust to most variations in assumptions; however, higher cost of self-testing, lower linkage to care for people whose diagnosis is a consequence of a positive self-test result, and lower threshold for antiretroviral therapy eligibility criteria could lead to situations in which self-testing is not cost-effective., Conclusions: This analysis suggests that introducing self-testing offers some health benefits and may well save costs., (© The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.)

Background: Patients on dialysis mount reduced immune responses compared with the general population. The Department of Health advises that these patients receive influenza and pneumococcal vaccinations at regular intervals-once yearly and every five years, respectively. This article investigates the uptake of these vaccinations in this patient population and seeks to examine factors that may influence vaccination status such as patient's language and presence of a general practitioner (GP) electronic vaccination reminder system. It also explores preferred site of vaccination for patients and GPs as these are primary care vaccinations yet patients have more frequent contact with their dialysis unit than their GP, blurring the boundaries between primary and specialized care., Methods: This is a retrospective study of all patients registered as dialysing at the North Middlesex University Hospital NHS Trust (NMUH) in September 2011. Information was obtained through GP letters, GP and patient questionnaires., Results: Of 154 patients, 133 were included in the data analysis. Nineteen per cent were up-to-date with both vaccinations and 67% with their influenza vaccination. Fifty per cent had received the influenza vaccination in the last two consecutive years. Thirty per cent were not up-to-date with either vaccination. There was no evidence of a difference in uptake in 2009 (P = 0.7564) and in 2010 (P = 0.7435) among those who could and could not speak English. Twenty-five per cent of GPs and 58.6% of patients preferred vaccination to occur in the dialysis unit. Unfortunately a high number of GPs did not provide information on whether they used an electronic vaccination reminder but the analysis from the information provided by the few respondents did not reveal any correlation between the presence of an electronic reminder and vaccination status., Conclusion: Most dialysis patients were not up-to-date with both vaccinations. They were, however, more up-to-date with their influenza than their pneumococcal vaccination. Non-English speakers did not appear to be disadvantaged. GP electronic reminder systems may have influenced influenza uptake but this study did not demonstrate a correlation and this is likely due to the lack of GP respondents; the effectiveness of electronic reminders merits further studies as a tool to improve vaccination rates in at-risk populations. Most patients visited their GP at least annually but preferred to receive their vaccinations at the hospital. Vaccinating in the dialysis unit and maintaining an electronic record accessible to GPs or generating a letter for GPs may help fill the vaccination gap in these patients. Overall, more evidence is required for the effectiveness of such vaccinations and their frequency, but in the meantime UK national guidelines were not being followed with a large proportion of patients remaining unvaccinated against influenza and in particular pneumococcal disease. This audit highlights the importance of local data collection, discussions around correlations influencing outcomes and publication of results to improve standards of care at a national level.

There are few data on the persistence of individual human immunodeficiency virus type 1 (HIV-1) transmitted drug resistance (TDR) mutations in the absence of selective drug pressure. We studied 313 patients in whom TDR mutations were detected at their first resistance test and who had a subsequent test performed while ART-naive. The rate at which mutations became undetectable was estimated using exponential regression accounting for interval censoring. Most thymidine analogue mutations (TAMs) and T215 revertants (but not T215F/Y) were found to be highly stable, with NNRTI and PI mutations being relatively less persistent. Our estimates are important for informing HIV transmission models.

Scale-up of antiretroviral therapy in low- and middle-income countries has been achieved by using a public health approach that involved national standard regimens and clinical monitoring in settings where laboratory infrastructure was not available. This strategy potentially allows for long periods of unrecognized viral failure, during which drug-resistant virus can be transmitted and this could compromise the long-term effectiveness of currently available first-line regimens. In response to this concern, the World Health Organization recommends population-based surveys to detect whether the prevalence of resistance in ART-naive people is reaching alerting levels. Whereas adherence counseling has to be an integral component of any treatment program, it is still unclear which threshold of transmitted drug resistance (TDR) should trigger additional targeted public health actions and which action is the most cost-effective. Mathematical models can contribute to answer these questions. In order to estimate the potential long-term impact of TDR on mortality in people on ART we used the Synthesis transmission model. TDR is predicted to have potentially significant impact on future HIV mortality. It is critical to remain vigilant over transmission of drug-resistant HIV.

Background: Plasma human immunodeficiency virus type 1 (HIV-1) RNA suppression <50 copies/mL is regarded as the optimal outcome of highly active antiretroviral therapy (HAART). Current viral load (VL) assays show increased sensitivity, but the significance of RNA detection <50 copies/mL is unclear., Methods: This study investigated the virologic outcomes of 1247 patients with VL <50 copies/mL at an arbitrary time point during HAART (= T0), according to whether the actual, unreported (T0)VL was 40-49 copies/mL, RNA detected <40 copies/mL (RNA(+)), or RNA not detected (RNA(-)), as measured by the Abbott Real Time assay. Predictors of rebound >50 and >400 copies/mL over 12 months following T0 were analyzed with Cox proportional hazards models incorporating the (T0)VL and demographic and clinical data., Results: Rebound rates >50 copies/mL were 34.2% for (T0)VL 40-49 copies/mL, 11.3% for RNA(+), and 4.0% for RNA(-); rebound rates >400 copies/mL were 13.0%, 3.8%, and 1.2%, respectively. The adjusted hazard ratios for rebound >50 copies/mL were 4.67 (95% confidence interval, 2.91-7.47; P < .0001) and 1.97 (1.25-3.11; P < .0001) with (T0)VL 40-49 copies/mL and RNA(+), respectively, relative to RNA(-), and 6.91 (2.90-16.47; P < .0001) and 2.88 (1.24-6.69; P < .0001), respectively, for rebound >400 copies/mL. The association was independent of adherence levels., Conclusions: In treated patients monitored by RealTime, a VL of 40-49 copies/mL and, to a lesser extent, RNA detection <40 copies/mL predict rebound >50 and >400 copies/mL independently of other recognized determinants. The goal of HAART may need to be revised to a lower cutoff than 50 copies/mL.