Search

ObjectivesKey populations, including sex workers, men who have sex with men, and people who inject drugs, have a high risk of HIV and sexually transmitted infections (STIs). We assessed the health and economic impacts of different HIV and syphilis testing strategies among three key populations in Viet Nam using a dual HIV/syphilis rapid diagnostic test (RDT).SettingWe used the Spectrum AIDS Impact Model to simulate the HIV epidemic in key populations in Viet Nam and evaluated five testing scenarios. We used a 15-year time horizon and all costs are from the provider’s perspective.ParticipantsWe include the entire population of Viet Nam in the model.InterventionsWe model five testing scenarios among key populations: 1) annual testing with an HIV rapid diagnostic test (RDT), 2) annual testing with a dual RDT, 3) biannual testing using dual RDT and HIV RDT, 4) biannual testing using HIV RDT, and 5) biannual testing using dual RDTs.Primary and secondary outcome measuresThe primary outcome is incremental cost-effectiveness ratios (ICERS). Secondary outcomes include HIV and syphilis cases and costs for each proposed intervention.ResultsAnnual testing using a dual HIV/syphilis RDT was cost saving and averted 3,206 HIV cases and treated 7,719 syphilis cases compared to baseline over 15 years. Biannual testing using one dual test and one HIV RDT, or two dual tests both averted an additional 875 HIV cases and were cost-effective ($1,024 and $2,518 per DALY averted, respectively). Annual or biannual HIV testing using HIV RDTs and separate syphilis tests were more costly and less effective than using one or two dual RDTs.ConclusionsAnnual or biannual HIV and syphilis testing using dual RDTs among key populations can be cost-effective and support countries in reaching global reduction goals for HIV and syphilis.STRENGTHS AND LIMITATIONS OF THIS STUDYStrength: Our model presents novel cost-effectiveness estimates for the use of dual HIV/syphilis testing in key populations that can inform health plannersStrength: We include five testing scale up scenarios using both HIV RDT and dual HIV/syphilis RDTStrength: Our model is informed by demographic, behavioral, and biological data from government sources, surveys, surveillance, publicly available reports, databases, and peer-reviewed literatureLimitation: We made some assumptions regarding the timing and uptake of HIV and syphilis testing among key populations that may be inaccurate.Limitation: Our model assumes that increased syphilis testing and treatment will not impact syphilis prevalence, however, it is unknown whether increased testing will reduce or increase syphilis prevalence.

BackgroundHIV testing and counseling is a key component of HIV prevention and the entry point into the treatment cascade, which improves for individual clinical outcomes and reduces onward HIV transmission. Current guidelines recommend at least annual testing for key populations. More frequent testing could provide health benefits, but these additional services increase the program the cost-effectiveness is not well-evaluated.MethodsWe used a compartmental mathematical model to simulate the health and economic impact of HIV testing one to four times per year for men who have sex with men, people who inject drugs, and female sex workers in Viet Nam. Model outcomes included costs, HIV infections, HIV-related deaths, and disability-adjusted life years (DALYs) associated with each scenario. We used an opportunity cost-based cost-effectiveness threshold of US $2,255 per DALY averted, discounted costs and health benefits at 3% annually, and used a time horizon from 2021 to 2030 to calculate incremental cost-effectiveness ratios (ICERs).ResultsCompared to the baseline scenario, more frequent HIV testing was estimated to incrementally avert 10.2%, 5.2%, 3.0%, and 1.6% discounted infections for one-, two-, three-, and four-tests per year, respectively. ICERs associated with each scenario ranged from $464, $1,190, $1,762, and $2,727 per DALY averted for one-, two-, three-, and four-tests per year, respectively.ConclusionsIncreased HIV testing frequency for key populations was projected to avert HIV incidence, mortality, and disability in Viet Nam and was cost-effective. Settings with a similar context should consider strategies on how to optimize retesting among key populations.

UNSTRUCTURED Mathematical modeling of COVID-19 transmission has been instrumental in the global pandemic, particularly to governments in many low- and middle-income countries (LMICs), where empirical data and active surveillance is limited. Simulations can be used to understand disease trajectory and impacts of policy options at little additional cost. We describe an automated, open-source, and web-based dashboard designed to empower Malawi government officials to understand the ramifications of certain policy interventions from a mathematical model of COVID-19 transmission. The dynamic dashboard allows policymakers to simulate scenarios of various COVID responses by allowing them to manipulate model inputs like percentage of population using cloth masks, percentage of population abiding by physical distancing recommendations, and the length of both these interventions in days. The dashboard’s outputs include COVID-19 cases, hospitalizations, intensive care unit (ICU) stays, and deaths based on the user-defined parameters and level of interest for the data (i.e., administrative levels like traditional authority-, district-, or national-level). It also compares the outputs from the user-defined simulation with a baseline scenario that conservatively estimates 15% of the population masking and 8% abiding by physical distancing guidelines. Our dynamic dashboard not only generates pertinent outputs to formulating a pandemic policy response, but it also offers an intuitive, streamlined, and real-time user experience to policymakers who may lack backgrounds in epidemiology and programming. LMICs should continue to invest in their country’s data collection, digital infrastructures, and technical training for key stakeholders to support widespread use of these evidence-based, decision-support tools in the future.

Our basic observations from daily experiences as well as sophisticated experiments suggest causality in various branches of physics (and beyond). Causality is mathematically reflected in the analyticity of the system's response function, which relates the dispersion of the system to the dissipation. We also observe that the dissipation is related to fluctuations in that system. By surveying introductory elements (and thus mostly undergraduate textbooks) of this relation, the student finds the interrelationship among different sub-disciplines of physics otherwise buried. A pedagogical experiment in class reveals a student's enjoyment in learning through this experience.Our basic observations from daily experiences as well as sophisticated experiments suggest causality in various branches of physics (and beyond). Causality is mathematically reflected in the analyticity of the system's response function, which relates the dispersion of the system to the dissipation. We also observe that the dissipation is related to fluctuations in that system. By surveying introductory elements (and thus mostly undergraduate textbooks) of this relation, the student finds the interrelationship among different sub-disciplines of physics otherwise buried. A pedagogical experiment in class reveals a student's enjoyment in learning through this experience.

Recipients of chimeric antigen receptor-modified T (CAR-T) cell therapies for B-cell malignancies are immunocompromised and at risk for serious infections. Vaccine immunogenicity is unknown in this population. We conducted a prospective observational study of the humoral immunogenicity of 2019-2020 inactivated influenza vaccines (IIV) in children and adults immediately prior to (n=7) or 13-57 months after (n=15) CD19-, CD20-, or BCMA-targeted CAR-T-cell therapy, as well as controls (n=8). Individuals post-CAR-T-cell therapy were in remission. We tested for antibodies to 4 vaccine strains at baseline and ≥1 time point after IIV using neutralization and hemagglutination inhibition assays. An antibody response was defined as a ≥4-fold titer increase from baseline at the first post-vaccine time point. Baseline A(H1N1) titers in the CAR-T cohorts were significantly lower compared to controls. Antibody responses to ≥1 vaccine strain occurred in 2 (29%) individuals before CAR-T-cell therapy; one individual maintained a response for >3 months post-CAR-T-cell therapy. Antibody responses to ≥1 vaccine strain occurred in 6 (40%) individuals vaccinated after CAR-T-cell therapy. An additional 2 (29%) and 6 (40%) individuals had ≥2-fold increases (at any time) in the pre- and post-CAR-T cohorts, respectively. There were no identified clinical or immunologic predictors of antibody responses. Neither severe hypogammaglobulinemia nor B-cell aplasia precluded antibody responses. These data support consideration for vaccination before and after CAR-T-cell therapy for influenza and other relevant pathogens such as SARS-CoV-2, irrespective of hypogammaglobulinemia or B-cell aplasia. Larger studies are needed to determine correlates of vaccine immunogenicity and durability in CAR-T-cell therapy recipients.Key PointsInfluenza vaccination was immunogenic pre- and post-CAR-T-cell therapy, despite hypogammaglobulinemia and B-cell aplasia.Vaccination with inactivated vaccines can be considered before CAR-T-cell therapy and in individuals with remission after therapy.

This paper presents the results of the Rubin Observatory Dark Energy Science Collaboration (DESC) 3x2pt tomography challenge, which served as a first step toward optimizing the tomographic binning strategy for the main DESC analysis. The task of choosing an optimal tomographic binning scheme for a photometric survey is made particularly delicate in the context of a metacalibrated lensing catalogue, as only the photometry from the bands included in the metacalibration process (usually riz and potentially g) can be used in sample definition. The goal of the challenge was to collect and compare bin assignment strategies under various metrics of a standard 3x2pt cosmology analysis in a highly idealized setting to establish a baseline for realistically complex follow-up studies; in this preliminary study, we used two sets of cosmological simulations of galaxy redshifts and photometry under a simple noise model neglecting photometric outliers and variation in observing conditions, and contributed algorithms were provided with a representative and complete training set. We review and evaluate the entries to the challenge, finding that even from this limited photometry information, multiple algorithms can separate tomographic bins reasonably well, reaching figures-of-merit scores close to the attainable maximum. We further find that adding the g band to riz photometry improves metric performance by ~15% and that the optimal bin assignment strategy depends strongly on the science case: which figure-of-merit is to be optimized, and which observables (clustering, lensing, or both) are included., Comment: 30 pages (incl. 12 in appendix), 12 figures. Version accepted for publication in the Open Journal of Astrophysics

We introduce a method for volumetric photoacoustic imaging from a single laser shot using compressive sensing. We demonstrate the accuracy and efficiency of a 3D pressure distribution reconstruction.

The COVID-19 global pandemic has had considerable health impact, including sub-Saharan Africa. In Malawi, a resource-limited setting in Africa, gaining access to data to inform the COVID-19 response is challenging. Information on adherence to physical distancing guidelines and reducing contacts are nonexistent, but critical to understanding and communicating risk, as well as allocating scarce resources. We present a case study which leverages aggregated call detail records into a daily data pipeline which summarize population density and mobility in an easy-to-use dashboard for public health officials and emergency operations. From March to April 2021, we have aggregated 6-billion calls and text messages and continue to process 12 million more daily. These data are summarized into reports which describe, quantify, and locate mass gatherings and travel between subdistricts. These reports are accessible via web dashboards for policymakers within the Ministry of Health and Emergency Operations Center to inform COVID-19 response efforts and resource allocation.

Introduction The COVID-19 pandemic has caused widespread disruptions including to health services. In the early response to the pandemic many countries restricted population movements and some health services were suspended or limited. In late 2020 and early 2021 some countries re-imposed restrictions. Health authorities need to balance the potential harms of additional SARS-CoV-2 transmission due to contacts associated with health services against the benefits of those services, including fewer new HIV infections and deaths. This paper examines these trade-offs for select HIV services. Methods We used four HIV simulation models (Goals, HIV Synthesis, Optima HIV and EMOD) to estimate the benefits of continuing HIV services in terms of fewer new HIV infections and deaths. We used three COVID-19 transmission models (Covasim, Cooper/Smith and a simple contact model) to estimate the additional deaths due to SARS-CoV-2 transmission among health workers and clients. We examined four HIV services: voluntary medical male circumcision, HIV diagnostic testing, viral load testing and programs to prevent mother-to-child transmission. We compared COVID-19 deaths in 2020 and 2021 with HIV deaths occurring now and over the next 50 years discounted to present value. The models were applied to countries with a range of HIV and COVID-19 epidemics. Results Maintaining these HIV services could lead to additional COVID-19 deaths of 0.002 to 0.15 per 10,000 clients. HIV-related deaths averted are estimated to be much larger, 19–146 discounted deaths per 10,000 clients. Discussion While there is some additional short-term risk of SARS-CoV-2 transmission associated with providing HIV services, the risk of additional COVID-19 deaths is at least 100 times less than the HIV deaths averted by those services. Ministries of Health need to take into account many factors in deciding when and how to offer essential health services during the COVID-19 pandemic. This work shows that the benefits of continuing key HIV services are far larger than the risks of additional SARS-CoV-2 transmission.

Many individuals with advanced glaucoma and retinal dystrophies have functional difficulty due to a loss of peripheral vision. These individuals may have sufficient central vision to read and perform visual tasks in a controlled situation, but are often unable to function in a cluttered, unstructured or chaotic environment (i.e. a normal social situation). This is because they lack the ability to be visually alerted to an incentive or threat outside the narrowed region of their central vision. Some groups of these patients, for example those with a diagnosis of retinitis pigmentosa, also experience nyctalopia (night blindness) meaning that time of day can alter their functional ability. Currently, there are limited options to aid these patients. Intel Corporation has developed a computer-based assistive device that may be useful for these individuals. Intel has recently made the design details and software available via the internet. The device consists of a vest or shirt with an attached depth-sensing camera, a computer and vibration transducers (6 on the vest and one on each foot). The transducers vibrate to alert the wearer to objects that are approaching them, or if they are walking, alert them to objects that they may be approaching. We propose to test subjects wearing the device to determine its usefulness. This will consist of participants with no known visual problems wearing goggles that will reduce their peripheral vision, replicating the effects of the diseases mentioned. The participants will be asked to walk through simple maze scenarios wearing the vibration vest and two different pairs of goggles. Two versions will be performed with the vest switched off and then it will be activated, equalling four mazes per participant. Each participant will also answer two short questionnaires, one before and one after using the device, to help determine the possible benefits and drawbacks of the device. The results will then be analysed to conclude whether an electronic device such as this could be useful to enhance visual function in those with reduced peripheral vision. This could then be applied to patients affected by these diseases.

Many individuals with advanced glaucoma and retinal dystrophies have functional difficulty due to a loss of their peripheral vision. These individuals may have sufficient central vision to read and perform visual tasks in a controlled situation, but are often unable to function in a cluttered, unstructured or chaotic environment (i.e. a normal social situation). This is because they lack the ability to be visually alerted to an incentive or threat outside the narrowed region of their central vision. Some groups of these patients, for example those with a diagnosis of retinitis pigmentosa, also experience nyctalopia (night blindness) meaning that time of day can alter their functional ability. Currently, there are limited options to aid these patients. Intel Corporation has developed a computer-based assistive device that may be useful for these individuals. Intel has recently made the design details and software available via the internet. The device consists of a vest or shirt with an attached depth-sensing camera, a computer and vibration transducers (6 on the vest and one on each foot). The transducers vibrate to alert the wearer to objects that are approaching them, or if they are walking, alert them to objects that they may be approaching. We propose to test subjects wearing the device to determine its usefulness. This will consist of participants with known reduced peripheral vision walking through simple maze scenarios first using their normal visual aid (if required) and then wearing the vibration vest. Variations of the maze will be carried out in both bright and dim lighting, equalling four mazes per subject. Each subject will also answer two short questionnaires, one before and one after using the device, to help determine the possible benefits and drawbacks of the device. The results will then be analysed to conclude whether an electronic device such as this could be useful to patients with reduced peripheral vision.

The Fogg Behavior Model (FBM) is a new framework which posits that behavior happens when three factors - motivation, ability, and a prompt - occur in the same moment. The FBM categorizes people into four groups based on motivation and ability and posits that those with high motivation and high ability will adopt a behavior when prompted. Two rounds of panel survey data from 617 married men in urban Pakistan were used to test this hypothesis. Multilevel mixed-effects logistic regression was used for the analysis. The results show the relationships between ability, motivation, the prompt and condom use to be as hypothesized by the FBM. After adjustment for a range of variables including fertility desires, education, and household wealth, the odds of condom use among men with high motivation and high ability were 34 times higher than the odds of condom use among men with low motivation and low ability. Moreover, the association between the prompt and condom use operated through increased motivation and ability. The FBM has potential for use in the design and evaluation of behavior change interventions in developing countries.

Introduction In 2014, the Government of Thailand recommended pre‐exposure prophylaxis (PrEP) as an additional HIV prevention programme within Thailand's National Guidelines on HIV/AIDS Treatment Prevention. However, to date implementation and uptake of PrEP programmes have been limited, and evidence on the costs and the epidemiological and economic impact is not available. Methods We estimated the costs associated with PrEP provision among men having sex with men (MSM) participating in a facility‐based, prospective observational cohort study: the Test, Treat and Prevent HIV Programme in Thailand. We created a suite of scenarios to estimate the cost‐effectiveness of PrEP and sensitivity of the results to the model input parameters, including PrEP programme effectiveness, PrEP uptake among high‐risk and low‐risk MSM, baseline and future antiretroviral therapy (ART) coverage, condom use, unit cost of delivering PrEP, and the discount rate. Results Drug costs accounted for 82.5% of the total cost of providing PrEP, followed by lab testing (8.2%) and personnel costs (7.8%). The estimated costs of providing the PrEP package in accordance with the national recommendation ranges from US$223 to US$311 per person per year. Based on our modelling results, we estimate that PrEP would be cost‐effective when provided to either high‐risk or all MSM. However, we found that the programme would be approximately 32% more cost‐effective if offered to high‐risk MSM than it would be if offered to all MSM, with an incremental cost‐effectiveness ratio of US$4,836 per disability‐adjusted life years (DALY) averted and US$7,089 per DALY averted respectively. Cost‐effectiveness acceptability curves demonstrate that 80% of scenarios would be cost‐effective when PrEP is provided solely to higher‐risk MSM. Conclusion We provide the first estimates on cost and cost‐effectiveness of PrEP in the Asia‐Pacific region, and offer insights on how to deliver PrEP in combination with ART. While the high drug cost poses a budgeting challenge, incorporating PrEP delivery into an existing ART programme could be a cost‐effective strategy to prevent HIV infections among MSM in Thailand.

We report on the design and experimental characterization of a surface-electrode multipole ion trap. Individual microscopic sugar particles are confined in the trap. The trajectories of driven particle motion are compared with a theoretical model, both to verify qualitative predictions of the model, and to measure the charge-to-mass ratio of the confined particle. The generation of harmonics of the driving frequency is observed as a key signature of the nonlinear nature of the trap. We remark on possible applications of our traps, including to mass spectrometry., Comment: Preprint format, 15 pages, 9 figures. Accepted into Journal of Applied Physics