scholarly journals Dynamics and optimal control of a spatial diffusion HIV/AIDS model with ART and PrEP treatments

2022 ◽  
Author(s):  
Liping Wang ◽  
Anwarud Din ◽  
Peng Wu
Keyword(s):  
Optimal Control ◽  
Hiv Transmission ◽  
Infected Individual ◽  
Epidemiological Data ◽  
Spatial Diffusion ◽  
Model Parameters ◽  
Hiv Intervention ◽  
Constant Diffusion ◽  
Sex With Men ◽  
Exposure Prophylaxis

In this paper, to investigate the synthetic effect of PrEP (pre-exposure prophylaxis) and ART (antiretrovial therapy) on HIV transmission among MSM (men who have sex with men) in heterogenous environment, an realistic HIV epidemic model with spatial diffusion is established. Here, HIV infectious people are divided into three immunity based compartments, i.e., CD4+ T cell count less than 350, between 350 and 500, and more than 500, respectively. The basic reproduction number $R_0$ is established and proved as a threshold parameter: The global asymptotic stability of the disease-free steady state holds for $R_0<1$, and the disease will be present if $R_0>1$. Considering the substantial advantages of PrEP and ART in controlling HIV transmissions among MSM, the optimal control problem is presented for the case of positive constant diffusion coefficients, which minimize the total population of susceptible individual and HIV infected individual, the cost of PrEP and ART thearpy. As an illustration of our theoretical results, we conduct numerical simulations. We also conduct an optimal control case study where model parameters are estimated from the demographic and epidemiological data from China. This work suggests: (1) Spatial factors cannot be ignored during the HIV intervention; (2)Taking the PrEP intervention measure for HIV transmissions among MSM as early as possible will help to improve the control efficiency and reduces its cost; (3) Reducing the PrEP drug costs will promote the efficiency of PrEP treatment in preventing the spread of HIV among MSM.

scholarly journals 1701. Added Benefits of Pre-exposure Prophylaxis Use on HIV Incidence with Minimal Changes in Efficiency in the Context of High Treatment Engagement among Men Who Have Sex with Men

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S833-S833
Author(s):  
Alyson L Singleton ◽  
Brandon D Marshall ◽  
Xiao Zang ◽  
Amy S Nunn ◽  
William C Goedel
Keyword(s):  
African American ◽  
Hiv Infection ◽  
Hiv Transmission ◽  
Treatment Engagement ◽  
Hiv Incidence ◽  
Black African ◽  
African American Msm ◽  
Sex With Men ◽  
Exposure Prophylaxis ◽  
High Treatment

Abstract Background Although there is ongoing debate over the need for substantial increases in PrEP use when antiretroviral treatment confers the dual benefits of reducing HIV-related morbidity and mortality and the risk of HIV transmission, no studies to date have quantified the potential added benefits of PrEP use in settings with high treatment engagement across variable sub-epidemics in the United States. Methods We used a previously published agent-based network model to simulate HIV transmission in a dynamic network of 17,440 Black/African American and White MSM in Atlanta, Georgia from 2015 to 2024 to understand how the magnitude of reductions in HIV incidence attributable to varying levels of PrEP use (0–90%) changes in potential futures where high levels of treatment engagement (i.e. the UNAIDS ‘90-90-90’ goals and eventual ‘95-95-95’ goals) are achieved and maintained, as compared to current levels of treatment engagement in Atlanta (Figure 1). Model inputs related to HIV treatment engagement among Black/African American and White men who have sex with men in Atlanta. A comparison of current levels of treatment engagement (Panel A) to treatment engagement at ‘90-90-90’ (Panel B) and ‘95-95-95’ goals (Panel C). Results Even at achievement and maintenance of ‘90-90-90’ goals, 75% PrEP coverage reduced incidence rates by an additional 67.9% and 74.2% to 1.53 (SI: 1.39, 1.70) and 0.355 (SI: 0.316, 0.391) per 100 person-years for Black/African American and White MSM, respectively (Figure 2), compared to the same scenario with no PrEP use. Additionally, an increase from 15% PrEP coverage to 75% under ‘90-90-90’ goals only increased person-years of PrEP use per HIV infection averted, a measure of efficiency of PrEP, by 8.1% and 10.5% to 26.7 (SI: 25.6, 28.0) and 73.3 (SI: 70.6, 75.7) among Black/African American MSM and White MSM, respectively (Figure 3). Overall (Panel A) and race-stratified (Panel B and Panel C) marginal changes in HIV incidence over ten years among Black/African American and White men who have sex with men in Atlanta across scenarios of varied levels of treatment engagement among agents living with HIV infection and levels of pre-exposure prophylaxis use among HIV-uninfected agents. Note: All changes are calculated within each set of treatment scenarios relative to a scenario where no agents use pre-exposure prophylaxis. Person-years of pre-exposure prophylaxis use per HIV infection averted among Black/African American (Panel A) and White (Panel B) men who have sex with men in Atlanta across scenarios of varied levels of treatment engagement among agents living with HIV infection and levels of pre-exposure prophylaxis use among HIV-uninfected agents. Note: The number of HIV infections averted is calculated within each set of treatment scenarios relative to a scenario where no agents use pre-exposure prophylaxis. Conclusion Even in the context of high treatment engagement, substantial expansion of PrEP use still contributes to meaningful decreases in HIV incidence among MSM with minimal changes in person-years of PrEP use per HIV infection averted, particularly for Black/African American MSM. Disclosures All Authors: No reported disclosures

Acceptability of a digital patient notification and linkage-to-care tool for French PrEPers (WeFLASH©): Key stakeholders' perspectives

2019 ◽  
Vol 30 (14) ◽  
pp. 1397-1407
Author(s):  
David Lessard ◽  
Alexandre Aslan ◽  
Jérémy Zeggagh ◽  
Stéphane Morel ◽  
David Michels ◽  
...  
Keyword(s):  
Linkage To Care ◽  
Epidemiological Data ◽  
Management Decision ◽  
Time Data ◽  
Transmitted Infection ◽  
Sti Prevention ◽  
Sexually Transmitted ◽  
Sex With Men ◽  
Access To Data ◽  
Exposure Prophylaxis

The objective of this study was to describe stakeholders’ perspectives on the acceptability of WeFLASH© (AADISS, Paris, France), a digital smartphone sexually transmitted infection (STI) patient notification (PN) tool to be launched among French HIV pre-exposure prophylaxis users (PrEPers). In Paris, Lyon, and Nice, we conducted 2-hour focus group discussions with PrEPers (n = 21) and community mediators (n = 10), and one-on-one interviews with PrEP-prescribing physicians (n = 5) and HIV/STI management decision-makers (n = 4). Recordings were transcribed. The analysis focused on perceived benefits and risks. Concerning benefits, participants mentioned that WeFLASH© could provide: improved PN and STI screening, by refining the notification of anonymous partners; customized linkage-to-care, by providing users with tailored information on care; and transferable epidemiological data, by filling a need for real-time data. Participants anticipated risks for: privacy and confidentiality and suggested specific security settings to protect users’ identity; sexual behavior and suggested game-like functions to improve the integration of the tool in sexual contexts; and fairness and emphasized the importance of making WeFLASH© accessible to all men who have sex with men. WeFLASH© could facilitate PN for an increasing proportion of anonymous partners met online, and empower users, including notified partners, on questions of confidentiality and consent, access to STI prevention and screening services, and access to data.

scholarly journals Impact of sexual trajectories of men who have sex with men on the reduction in HIV transmission by pre-exposure prophylaxis

Epidemics ◽  
2019 ◽  
Vol 28 ◽  
pp. 100337 ◽  
Author(s):  
Ganna Rozhnova ◽  
Janneke C.M. Heijne ◽  
Maartje Basten ◽  
Chantal den Daas ◽  
Amy Matser ◽  
...  
Keyword(s):  
Hiv Transmission ◽  
Sex With Men ◽  
Exposure Prophylaxis

scholarly journals Influence of serosorting and intervention-mediated changes in serosorting on the population-level HIV transmission impact of pre-exposure prophylaxis among men who have sex with men: a mathematical modelling study

2020 ◽  
Author(s):  
Linwei Wang ◽  
Nasheed Moqueet ◽  
Anna Simkin ◽  
Jesse Knight ◽  
Huiting Ma ◽  
...  
Keyword(s):  
Condom Use ◽  
Hiv Transmission ◽  
Population Level ◽  
Poor Adherence ◽  
Hiv Incidence ◽  
Individual Level ◽  
Prep Implementation ◽  
Mixing Patterns ◽  
Sex With Men ◽  
Exposure Prophylaxis

ABSTRACTBackgroundHIV 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 proportional to availability by HIV-status (sero-proportionate)), and reproduced stable HIV epidemics (2013-2018) with HIV-prevalence 10.3%-24.8%, undiagnosed fraction 4.9%-15.8%, and treatment coverage 82.5%-88.4%. We simulated PrEP-intervention reaching stable coverage by year-1 and compared absolute difference in relative HIV-incidence reduction 10-year post-intervention (PrEP-impact) between: models with serosorting vs. sero-proportionate mixing; and scenarios in which PrEP users stopped vs. continued serosorting. We examined sensitivity of results to PrEP-effectiveness (44%-99%) and coverage (10%-50%).FindingsModels with serosorting predicted a larger PrEP-impact compared with models with sero-proportionate mixing under all PrEP-effectiveness and coverage assumptions (median (inter-quartile-range): 8.1%(5.5%-11.6%)). PrEP users” stopping serosorting reduced PrEP-impact compared with when PrEP users continued serosorting: reductions in PrEP-impact were minimal (2.1%(1.4%-3.4%)) under high PrEP-effectiveness (86%-99%); however, could be considerable (10.9%(8.2%-14.1%)) under low PrEP effectiveness (44%) and high coverage (30%-50%).InterpretationModels assuming sero-proportionate mixing may underestimate population-level HIV-incidence reductions due to PrEP. PrEP-mediated changes in serosorting could lead to programmatically-important reductions in PrEP-impact under low PrEP-effectiveness (e.g. poor adherence/retention). Our findings suggest the need to monitor sexual mixing patterns to inform PrEP implementation and evaluation.FundingCanadian Institutes of Health ResearchRESEARCH IN CONTEXTEvidence before this studyWe searched PubMed for full-text journal articles published between Jan 1, 2010, and Dec 31, 2017, using the MeSH terms “pre-exposure prophylaxis (PrEP)” and “homosexuality, male” and using key words (“pre-exposure prophylaxis” or “preexposure prophylaxis” or “PrEP”) and (“men who have sex with men” or “MSM”) in titles and abstracts. Search results (520 records) were reviewed to identify publications which examined the population-level HIV transmission impact or population-level cost-effectiveness of PrEP in high-income settings. We identified a total of 18 modelling studies of PrEP impact among men who have sex with men (MSM) and four studies were based on the same model with minor variations (thus only the most recent one was included). Among the 15 unique models of PrEP impact, three included serosorting. A total of nine models have assessed the individual-level behaviour change among those on PrEP and its influence on the transmission impact of PrEP. Specifically, the models examined increases in number of partners and reductions in condom use. Most models predicted that realistic increases in partner number or decreases in condom use would not fully offset, but could weaken, PrEP”s impact on reducing HIV transmission. We did not identify any study that examined the influence of serosorting patterns on the estimated transmission impact of PrEP at the population-level, or what could happen to HIV incidence if the use of PrEP changes serosorting patterns.Added value of this studyWe used a mathematical model of HIV transmission to estimate the influence of serosorting and PrEP-mediated changes in serosorting on the transmission impact of PrEP at the population-level among MSM. We found the impact of PrEP was higher under epidemics with serosorting, compared with comparable epidemics simulated assuming sero-proportionate mixing. Under epidemics with serosorting, when PrEP users stopped serosorting (while other men continue to serosort among themselves) we found a reduced PrEP impact compared with scenarios when PrEP users continued to serosort. The magnitude of reduction in PrEP impact was minimal if PrEP-effectiveness was high; however, could be programmatically-meaningful in the context of low PrEP-effectiveness (e.g., poor adherence or retention) and high PrEP coverage. To our knowledge, our study is the first to directly examine the influence of serosorting and PrEP-mediated changes in serosorting on the transmission impact of PrEP and its underlying mechanism.Implications of all the available evidenceOur findings suggest that models which do not consider baseline patterns of serosorting among MSM could potentially underestimate PrEP impact. In addition to monitoring individual-level behavioural change such as condom use, our findings highlight the need to monitor population-level sexual mixing patterns and their changes over time among MSM in the design and evaluation of PrEP implementation.

Social determinants of self-reported pre-exposure prophylaxis use among a national sample of US men who have sex with men

2019 ◽  
Vol 96 (5) ◽  
pp. 368-374
Author(s):  
Brian A Chu ◽  
Erick R Castellanos ◽  
Manuel M Gonzales ◽  
Thomas W Gaither
Keyword(s):  
Social Determinants ◽  
Hiv Transmission ◽  
National Sample ◽  
Black Msm ◽  
The South ◽  
Southern Us ◽  
The Usa ◽  
Sex With Men ◽  
Using Data ◽  
Exposure Prophylaxis

PurposeVarious disparities exist in HIV transmission among men who have sex with men (MSM). Pre-exposure prophylaxis (PrEP) has been shown to decrease the acquisition of HIV, but there is variation in uptake within the MSM population. We aim to characterise PrEP use and correlates of self-reported PrEP use in a large national sample of urban MSM in the USA.MethodsUsing data from a geosocial-networking application, a national sample (n=3744) from the largest 50 metropolitan centres in the USA was obtained.ResultsWe found 18.1% (95% CI 16.8 to 19.3) of profiles reported using PrEP, with decreased reported PrEP use in younger MSM aged 18–24 years (adjusted OR (aOR)=0.5, 95% CI 0.3 to 0.7), obese MSM (aOR=0.5, 95% CI 0.3 to 0.9), black MSM (aOR=0.6, 95% CI 0.4 to 0.9) and MSM in the South (aOR=0.7, 95% CI 0.5 to 0.9).ConclusionSignificant disparities exist in PrEP reporting by age and among black, Southern US and obese MSM. More research is needed to better understand these disparities.

Acceptability of HIV Pre-exposure Prophylaxis (PrEP) and Opinions on PrEP Service Delivery Among Men Who Have Sex With Men in Singapore: A Qualitative Study

2019 ◽  
Vol 31 (2) ◽  
pp. 152-162 ◽  
Author(s):  
Chen Seong Wong ◽  
P. Arun Kumar ◽  
Christina M. Wong ◽  
Bryan C. H. Choong ◽  
Oliver Z. Lim ◽  
...  
Keyword(s):  
Hiv Transmission ◽  
Attractive Alternative ◽  
Patient Centered ◽  
Related Services ◽  
Qualitative Descriptive ◽  
Potential Benefits ◽  
Sex With Men ◽  
Exposure Prophylaxis ◽  
The Cost ◽  
Barriers And Motivators

PrEP is effective in preventing HIV transmission among at-risk HIV-negative MSM. A qualitative descriptive study with five focus group discussions (N = 33) involving a purposively recruited sample of Singaporean MSM was conducted from August 2016 to April 2017 to understand local perspectives on potential barriers and motivators to the adoption of PrEP, prior to the implementation of PrEP services in Singapore. Knowledge of PrEP was high, and many viewed PrEP as an attractive alternative to condoms for HIV prevention. Concerns about PrEP included the cost of PrEP and related services, the frequency of PrEP-related clinic visits, fear of side effects, and the stigma associated with using PrEP. Participants felt PrEP was best provided by MSM-friendly providers, and more needed to be done to increase awareness of the effectiveness of PrEP. Access to PrEP for MSM in Singapore has to be affordable, patient-centered, and convenient to maximize the potential benefits of PrEP.

scholarly journals An alarming high prevalence of resistance-associated mutations to macrolides and fluoroquinolones in Mycoplasma genitalium in Belgium: results from samples collected between 2015 and 2018

2020 ◽  
pp. sextrans-2020-054511
Author(s):  
Irith De Baetselier ◽  
Chris Kenyon ◽  
Wim Vanden Berghe ◽  
Hilde Smet ◽  
Kristien Wouters ◽  
...  
Keyword(s):  
Dna Sequencing ◽  
Ribosomal Rna ◽  
Hiv Transmission ◽  
Mycoplasma Genitalium ◽  
Fluoroquinolone Resistance ◽  
Routine Surveillance ◽  
High Prevalence ◽  
Sex With Men ◽  
Exposure Prophylaxis ◽  
23S Ribosomal Rna

ObjectivesThe number of reported cases of multiresistant Mycoplasma genitalium (MG) is increasing globally. The aim of this study was to estimate the prevalence of macrolide and possible fluoroquinolone resistance-associated mutations (RAMs) of MG in Belgium.MethodsThe study was performed retrospectively on two sets of MG-positive samples collected in Belgium between 2015 and 2018. The first set of samples originated from routine surveillance activities and the second set came from a cohort of men who have sex with men (MSM) using pre-exposure prophylaxis to prevent HIV transmission. Detection of RAMs to macrolides and fluoroquinolones was performed on all samples using DNA sequencing of the 23S ribosomal RNA gene, the gyrA gene and the parC gene.ResultsSeventy-one per cent of the MG samples contained a mutation conferring resistance to macrolides or fluoroquinolones (ParC position 83/87). RAMs were more frequently found among men compared with women for fluoroquinolones (23.9% vs 9.1%) and macrolides (78.4% vs 27.3%). Almost 90% of the MG infections among MSM possessed a RAM to macrolides (88.4%). In addition, 18.0% of the samples harboured both macrolides and fluoroquinolone RAMs; 3.0% in women and 24.2% in MSM. Being MSM was associated with macrolide RAMs (OR 15.3), fluoroquinolone RAMs (OR 3.8) and having a possible multiresistant MG infection (OR 7.2).ConclusionThe study shows an alarmingly high prevalence of MG with RAMs to macrolides and fluoroquinolones in Belgium. These results highlight the need to improve antimicrobial stewardship in Belgium in order to avoid the emergence of untreatable MG.

scholarly journals Inconsistent HIV pre‐exposure prophylaxis use and HIV transmission in men who have sex with men (MSM)

2020 ◽  
Vol 23 (8) ◽  
Author(s):  
Daniel Richardson ◽  
Jane Shapiro ◽  
David A Lewis ◽  
Iryna Zablotska ◽  
Keyword(s):  
Hiv Transmission ◽  
Sex With Men ◽  
Exposure Prophylaxis

scholarly journals Statewide Evaluation of New HIV Diagnoses in Rhode Island: Implications for Prevention

2018 ◽  
Vol 133 (4) ◽  
pp. 489-496
Author(s):  
Philip A. Chan ◽  
Madeline C. Montgomery ◽  
Jennifer Rose ◽  
Alec Tributino ◽  
Christina Crowley ◽  
...  
Keyword(s):  
United States ◽  
Rhode Island ◽  
Latent Class ◽  
Hiv Transmission ◽  
The United States ◽  
Newly Diagnosed ◽  
Foreign Born ◽  
Class 1 ◽  
Sex With Men ◽  
Exposure Prophylaxis

Objectives: Patterns of HIV transmission vary widely across demographic groups. Identifying and engaging these groups are necessary to prevent new infections and diagnose disease among people who are unaware of their infection. The objective of this study was to determine characteristics of newly diagnosed individuals across an entire state to determine patterns of HIV transmission. Methods: We evaluated data on people with new HIV diagnoses in Rhode Island from 2013 through 2015. We performed a latent class analysis (LCA) to identify underlying demographic and behavioral characteristics of people with newly diagnosed HIV. Results: Of 167 people with new HIV diagnoses interviewed in Rhode Island from 2013 through 2015, 132 (79%) were male, 84 (50%) were nonwhite, 112 (67%) were men who have sex with men (MSM), 112 (67%) were born in the United States, and 61 (37%) were born in Rhode Island. LCA revealed 2 major classes. Of the 98 people in class 1, 96% were male, 85% were MSM, 80% were white, 94% were born in the United States, and 80% believed they acquired HIV in Rhode Island. Class 2 was 63% male and 69% Hispanic/Latino; 29% were born in the United States, and 61% believed they acquired HIV in Rhode Island. Conclusions: Most new HIV diagnoses in Rhode Island were among MSM born in the United States, and a substantial number were likely infected in-state. People with newly diagnosed HIV who were foreign-born, including Hispanic/Latino and heterosexual groups, were less likely to have acquired HIV in Rhode Island than were MSM. HIV prevention approaches, including pre-exposure prophylaxis, should be adapted to the needs of specific groups. Rhode Island offers lessons for other states focused on eliminating HIV transmission.

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