AIDS

ObjectiveWe aimed to determine whether urine tenofovir (TFV) and dried blood spot (DBS) tenofovir diphosphate (TFV-DP) concentrations are associated with concurrent HIV viraemia. DesignCross-sectional study among people with HIV (PWH) receiving tenofovir disoproxil fumarate (TDF)-based antiretroviral therapy (ART). MethodsWe used dual tandem liquid chromatography and mass spectrometry to measure urine TFV and DBS TFV-DP concentrations, and evaluated their associations with concurrent viraemia ...

BackgroundIdentifying communities with high HIV prevalence is crucial for public health officials, researchers, and policymakers to effectively monitor the epidemic and evaluate interventions. Population-based HIV biomarker surveys face logistical challenges such as cost, need for personnel trained in specimen collection, specimen transport and processing, and participant reluctance to test due to factors such as stigma, history of recent testing, and the perception of being at low risk for HIV ...

BackgroundLong-acting injectable HIV pre-exposure prophylaxis (LAI-PrEP) is reportedly efficacious, although full trial results have not been published. We used a dynamic network model of HIV transmission among men who have sex with men (MSM) to assess the population impact of LAI-PrEP when available concurrently with daily-oral (DO) PrEP. MethodsThe reference model represents the current HIV epidemiology and DO-PrEP coverage (15% among indicated) among MSM in the southeastern US. Primary analy...

Oral HIV pre-exposure prophylaxis (PrEP) effectively prevents infection when taken during periods of risk, however, its population-level effectiveness is hindered by incomplete uptake, adherence, and retention. Since PrEP became available free-of-cost in British Columbia (BC), Canada, in January 2018, uptake has been rapid among gay, bisexual, and other men who have sex with men (GBM). Epidemiological evidence suggests adding PrEP onto a background of generalized access to free antiretroviral th...

BackgroundInequalities in the antiretroviral therapy (ART) cascade across subpopulations remain an ongoing challenge in the global HIV response. Eswatini achieved the UNAIDS 95-95-95 targets by 2020, with differentiated programs to minimize inequalities across subpopulations, including for female sex workers (FSW) and their clients. We sought to estimate additional HIV infections expected in Eswatini if cascade scale-up had not been equal, and under which epidemic conditions these inequalities c...

IntroductionPre- and post-exposure prophylaxis (PrEP and PEP) are important pillars of the HIV prevention portfolio to reduce the risk of infection just before or after HIV exposure. While PrEP efficacy has been elucidated in many randomized clinical trials, corresponding data for PEP is extremely difficult to obtain in a controlled setting. Consequently, it is almost impossible to study the impact of PEP initiation delay and duration on HIV risk reduction clinically, which would inform recommen...

IntroductionHIV remains a global public health challenge, with social determinants such as stigma influencing transmission dynamics, access to testing, and treatment. HIV stigma shapes both individual behaviour and community responses to HIV. However, modelling approaches have rarely represented the complex role of stigma in HIV epidemics. Our study introduces an innovative modelling framework designed to capture the interplay between stigma and HIV transmission dynamics. MethodsWe modelled eff...

HIV associated neurocognitive disorder (HAND) remains an important HIV-associated comorbidity despite antiretrovirals (ARVs). Cerebrospinal fluid (CSF) escape/discordance is now recognised in the context of individuals with a reconstituted immune system with an estimated prevalence of 10%. However, the contribution of CSF escape/discordance to HAND remains uncertain. Furthermore, a latent reservoir of HIV in the brain has implications for lasting cure strategies. Little is known about the preval...

BackgroundCharacterising disparities in HIV infection across populations by gender, age, and HIV risk is key information to guide intervention priorities. We compared 9 models representing 15 different settings across Africa to assess how indicators measuring HIV acquisitions, transmissions, or potential long-term infections influence estimates of the contribution of different populations to new infections, including key populations (KPs, including female sex workers (FSW), their clients, men wh...

IntroductionTo enable comparable global assessments of viral load suppression (VLS) among people living with HIV on antiretroviral therapy (ART), UNAIDS applies a model to adjust VLS estimates reported at different thresholds to a common VL [≤]1000 copies/mL definition. We assessed performance of the current reverse Weibull model and alternatives using survey data from sub-Saharan Africa. MethodsUsing data from 21 Population-based HIV Impact Assessment surveys (PHIAs) in 16 sub-Saharan Afric...

BackgroundHIV pre-exposure prophylaxis (PrEP) has been recommended and partly subsidized in Quebec since 2013. We aimed to evaluate the population-level impact of PrEP on HIV transmission among men who have sex with men (MSM) in Montreal over 2013-2021. MethodsWe used an agent-based mathematical model of sexual HIV transmission to estimate the fraction of HIV acquisitions averted by PrEP compared to a counterfactual scenario without PrEP. The model was calibrated to local MSM survey and cohort ...

ObjectivesTo quantify the all-cause excess death rate of people living with HIV/AIDS (PWHA) during the multi-year 2020-2022 COVID-19 pandemic in the United States (U.S.), including stratifications by sex, age, race/ethnicity, and region. DesignUsing publicly available data from the CDC NCHHSTP AtlasPlus dashboard, we employed the ensemble n-subepidemic modeling framework (SubEpiPredict toolbox). This dynamic, uncertainty-aware approach was used to generate counterfactual forecasts of U.S. death...

BackgroundFollowing successful intensive interventions to rapidly increase HIV awareness, antiretroviral therapy (ART) coverage, and viral suppression, HIV programmes in eastern and southern Africa must now consider whether to scale-back certain programmes, such as widespread general population HIV testing services (general HTS), without risking a resurging epidemic or substantially increasing long-term ART need through slowed incidence declines. MethodsWe used a mathematical model (Thembisa) t...

BackgroundHIV pre-exposure prophylaxis (PrEP) may change serosorting patterns. We examined the influence of serosorting on the population-level HIV transmission impact of PrEP, and how impact could change if PrEP users stopped serosorting. MethodsWe developed a compartmental HIV transmission model parameterized with bio-behavioural and HIV surveillance data among men who have sex with men in Canada. We separately fit the model with serosorting and without serosorting (random partner-selection p...

BackgroundA third of people living with HIV (PLHIV) in Western Africa had an undiagnosed infection in 2020. In 2019-2021, the ATLAS programme has distributed a total of 380 000 HIV self-testing (HIVST) kits to key populations (KP) including female sex workers (FSW) and men who have sex with men (MSM), and their partners in Cote dIvoire, Mali and Senegal. We predicted the potential impact of ATLAS and of national HIVST scale-up strategies among KP. MethodsA deterministic model of HIV transmissio...

BackgroundPeople who inject drugs (PWID) in Kenya have a high prevalence of HIV (14-26%) and HCV (11-36%). Needle and syringe programmes (NSP) and antiretroviral therapy (ART) have high coverage among PWID, while HCV treatment and opioid substitution therapy (OST) access is low. MethodsA dynamic model of HIV (sexual and injecting-related) and HCV (injecting-related) transmission among PWID was calibrated using Bayesian methods to data from Nairobi and the Coastal region. We projected the impact...

BackgroundHIV incidence in sub-Saharan Africa has declined substantially since 2000 according to epidemic estimates published by UNAIDS. These estimates, derived by fitting mathematical models to national surveillance data, guide HIV programmes and epidemic response strategies. We assessed whether the level and age distribution of HIV incidence from modelled estimates were consistent with empirical HIV incidence observations, and whether incidence levels and trends were systematically different ...

BackgroundRecent declines in HIV incidence among adolescent girls and young women (AGYW) in Africa are often attributed to the expansion of biomedical interventions such as antiretroviral therapy and voluntary medical male circumcision. However, changes in sexual behaviour may also play a critical role. Understanding the relative contributions of these factors is essential for developing strategies to sustain and further reduce HIV transmission. MethodsWe conducted a mathematical modelling stud...

ObjectiveThe immunogenic nature of COVID-19 mRNA vaccines led to some initial concern that these could stimulate the HIV reservoir. We analyzed changes in plasma HIV loads (pVL) and reservoir size following COVID-19 mRNA vaccination in 62 people with HIV (PWH) receiving antiretroviral therapy (ART), and analyzed province-wide trends in pVL before and after the mass vaccination campaign. DesignLongitudinal observational cohort and province-wide analysis. Methods62 participants were sampled pre-...

Iron homeostasis is essential for brain health, and iron is also required for HIV replication, but the role of iron is largely unexplored in HIV-associated neurocognitive disorders. These disorders remain extremely common in people with HIV, despite antiretroviral therapy capable of suppressing viral replication, and they involve damage to white matter tracts and synaptodendritic architecture in the brain. We hypothesized that cerebrospinal fluid (CSF) levels of iron and two proteins involved in...