High proportion of post-migration HIV acquisition in migrant men who have sex with men receiving HIV care in the Paris region, and associations with social disadvantage and sexual behaviours: results of the ANRS-MIE GANYMEDE study, France, 2021 to 2022.

BackgroundSome migrant men who have sex with men (MSM) acquire HIV in France.AimsWe investigated, in migrant MSM receiving HIV care in France, the (i) rate of post-migration-HIV acquisition in France, (ii) delay between arrival and HIV acquisition and (iii) factors affecting HIV acquisition within 1 year after migration.MethodsThis cross-sectional study focused on ≥ 18-year-old MSM born outside France, receiving HIV care in the Paris region. Information on migration history, socioeconomic condition, sexual activity, and health was collected in May 2021-June 2022 through self-administered questionnaires and medical records. Post-migration-HIV-acquisition rate and delay between arrival in France and HIV acquisition were estimated from biographical data and CD4+ T-cell counts. Predictors of HIV acquisition within 1 year after migration were determined using logistic regression.ResultsOverall post-migration HIV-acquisition rate was 61.7% (715/1,159; 95%CI: 61.2-62.2), ranging from 40.5% (95%CI: 39.6-41.6) to 85.4% (95%CI: 83.9-86.0) in participants from Latin America and North Africa. Among post-migration-HIV acquisitions, those within 1 year after migration represented 13.1% overall (95%CI: 11.6-14.6), being highest in participants from sub-Saharan Africa (25%; 95%CI: 21.5-28.3). Participants ≥ 15-years old at migration, with post-migration-acquired HIV, had a 7.5-year median interval from arrival in France to HIV acquisition (interquartile range (IQR): 3.50-14.75). Older age at arrival, region of origin (sub-Saharan Africa and Asia), degree of social disadvantage and numbers of sexual partners were independently associated with acquiring HIV within 1 year in France.ConclusionOur findings may guide HIV prevention policies for most vulnerable migrants to Europe.

Impact of voluntary testing on infectious disease epidemiology: A game theoretic approach.

The World Health Organization recommends test-and-treat interventions to curb and even eliminate epidemics of HIV, viral hepatitis, and sexually transmitted infections (e.g., chlamydia, gonorrhea, syphilis and trichomoniasis). Epidemic models show these goals are achievable, provided the participation of individuals in test-and-treat interventions is sufficiently high. We combine epidemic models and game theoretic models to describe individual's decisions to get tested for infectious diseases within certain epidemiological contexts, and, implicitly, their voluntary participation to test-and-treat interventions. We develop three hybrid models, to discuss interventions against HIV, HCV, and sexually transmitted infections, and the potential behavioral response from the target population. Our findings are similar across diseases. Particularly, individuals use three distinct behavioral patterns relative to testing, based on their perceived costs for testing, besides the payoff for discovering their disease status. Firstly, if the cost of testing is too high, then individuals refrain from voluntary testing and get tested only if they are symptomatic. Secondly, if the cost is moderate, some individuals will test voluntarily, starting treatment if needed. Hence, the spread of the disease declines and the disease epidemiology is mitigated. Thirdly, the most beneficial testing behavior takes place as individuals perceive a per-test payoff that surpasses a certain threshold, every time they get tested. Consequently, individuals achieve high voluntary testing rates, which may result in the elimination of the epidemic, albeit on temporary basis. Trials and studies have attained different levels of participation and testing rates. To increase testing rates, they should provide each eligible individual with a payoff, above a given threshold, each time the individual tests voluntarily.

Acquisition du virus de l'immunodéficience humaine et parcours de vie d'hommes ayant des rapports sexuels avec d'autres hommes et ayant émigré en France : une enquête exploratoire.

INTRODUCTION: The ANRS 14058 Ganymede study aims to determine the proportion post-migration HIV-seroconversion in a sample of HIV-positive men having sex with men (MSM) born outside of France and receiving medical care in Paris region (Île-de-France). The study, based on a self-questionnaire, is also focused on the life course of these MSM before, during and after the migration process. PURPOSE OF RESEARCH: The paper refers to a qualitative exploratory study, taking place as a prerequisite for the Ganymede study, in order to refine its questionnaire. The purpose of these interviews was also to explore the migratory motivations and experiences, the sexual biography, and the health history, of a sample of seropositive MSM born outside of France, and to illustrate the diversity of this epidemiological category. RESULTS: Forteen respondents participated in the interview study. Nine of them have learned of their HIV-positive status after having emigrated to France. None of the respondents mentioned a major barrier to medical care access and HIV follow-up. The obstacles they reported were related to the coverage of medical expenses, due to their possible precarious legal and social situation. These men were exposed to the effects of power relations, leading to discrimination and violence, whose wider impacts on health were weakly evoked. CONCLUSIONS: Although the findings of the exploratory study are not to be generalized, they illustrate the health issues of the interviewees, and the wide diversity of their biographies and life courses, emphasizing the impact of gender and class power relations as a source of social and health inequalities, and precariousness. They invite therefore to describe this epidemiological category of "MSM born outside of France" in a more heterogeneous way.

Psychosocial factors involved in the very infrequent use of HIV testing among French MSM: a cross-sectional study.

BACKGROUND: Among men who have sex with men (MSM) in France, the average time between infection and testing is too long, leading to late diagnosis. A better understanding of very infrequent HIV testing (VIT; i.e. have not tested for at least 6 years) could help reach unknowingly long-infected MSM. Thus, we aim to identify psychosocial factors associated with VIT among MSM in France. METHODS: We conducted a multivariate regression on the data collected via a cross-sectional survey among 315 MSM. RESULTS: 11.1% (n = 35) had VIT. Being over 50, not knowing about the existence of HIV self-testing, having predominantly heterosexual friends, and the level of belief in the effectiveness of treatment as prevention were significantly associated with VIT. CONCLUSION: We call for the development, at the same time, of programs that operate at the individual, institutional and societal levels. In particular, we recommend diversifying the modes of promotion and access to prevention tools, especially for MSM over 50 years old or with little or no connection to the gay community.

Cost-effectiveness of hepatitis C virus test-and-treat and risk reduction strategies among men who have sex with men living with HIV in France.

INTRODUCTION: Studies suggest that hepatitis C virus (HCV) micro-elimination is feasible among men who have sex with men (MSM) living with human immunodeficiency virus (HIV), through treatment-as-prevention and interventions aimed at reducing risk behaviours. However, their economic impact is poorly understood. The aim of this study was to assess the cost-effectiveness of HCV screening and risk reduction strategies in France. METHODS: A compartmental deterministic mathematical model was developed to describe HCV disease transmission and progression among MSM living with HIV in France. We evaluated different combinations of HCV screening frequency (every 12, 6 or 3 months) and risk reduction strategies (targeting only high-risk or all MSM) from 2021 onwards. The model simulated the number of HCV infections, life-expectancy (LYs), quality-adjusted life-expectancy (QALYs), lifetime costs and incremental cost-effectiveness ratio (ICER) over a lifetime horizon (leading to an end of the simulation in 2065). RESULTS: All strategies increased QALYs, compared with current practices, that is yearly HCV screening, with no risk reduction. A behavioural intervention resulting in a 20% risk reduction in the high-risk group, together with yearly screening, was the least expensive strategy, and, therefore, cost-saving compared to current practices. The ICER per QALY gained for the strategy combining risk reduction for the high-risk group with 6-month HCV screening, compared to risk reduction with yearly screening, was €61,389. It also prevented 398 new HCV infections between 2021 and 2065, with a cost per infection averted of €37,790. All other strategies were dominated (more expensive and less effective than some other available alternative) or not cost-effective (ICER per QALY gained > €100,000). CONCLUSIONS: In the French context, current HCV screening practices without risk reduction among MSM living with HIV cannot be justified on economic grounds. Risk reduction interventions targeted to high-risk individuals-alongside screening either once or twice a year-could be cost-effective depending on the policymaker's willingness-to-pay.

Projection of age of individuals living with HIV and time since ART initiation in 2030: estimates for France.

INTRODUCTION: Thanks to antiretroviral treatment (ART), people living with HIV (PLHIV) are living longer and ageing. However, ageing involves increased risks of co-morbidities, which also depend on when PLHIV individuals started ART. To tackle the HIV age-related upcoming challenges, knowledge of the current and future age structure of the HIV population is needed. Here, we forecast the demographic profile of the adult population living with diagnosed HIV (aPLdHIV) in France until 2030, accounting for the impact of the ART initiation period on mortality. METHODS: We used national data from the French Hospital Database on HIV (ANRS CO4-FHDH) and a sample of the National Health Data System to, first, characterize the aPLdHIV in 2018 and estimate their mortality rates according to age, sex and ART initiation period. Second, we used national HIV surveillance data to define three scenarios for the numbers of newly diagnosed HIV cases over 2019-2030: 30% decrease in HIV cases (S1), status quo situation (S2) and epidemic elimination (S3). We then combined these data using a matrix model, to project the age structure of aPLdHIV and time since ART initiation. RESULTS: In 2018, there was an estimated 161,125 aPLdHIV (33% women), of which 55% were aged 50 or older (50+), 22% aged 60+ and 8% aged 70+. In 2030, the aPLdHIV would grow to 195,246 for S1, 207,972 for S2 and 167,221 for S3. Whatever the scenario, in 2030, the estimated median time since ART initiation would increase and age distribution would shift towards older ages: with 65-72% aPLdHIV aged 50+, 42-48% 60+ and 17-19% 70+. This corresponds to ∼83,400 aPLdHIV (28% women) aged 60+, among which ∼69% started ART more than 20 years ago (i.e. before 2010) and ∼39% ≥30 years ago (i.e. before 2000), and to ∼33,100 aPLdHIV (27% women) aged 70+, among which ∼72% started ART ≥20 years ago and ∼43% ≥30 years ago. CONCLUSIONS: By 2030, in France, close to 20% of the aPLdHIV will be aged 70+, of which >40% would have started ART more than 30 years ago. These estimates are essential to adapt co-morbidities screening and anticipate resource provision in the aged care sector.

HIV seroprevalence in five key populations in Europe: a systematic literature review, 2009 to 2019.

BackgroundIn Europe, HIV disproportionately affects men who have sex with men (MSM), people who inject drugs (PWID), prisoners, sex workers, and transgender people. Epidemiological data are primarily available from national HIV case surveillance systems that rarely capture information on sex work, gender identity or imprisonment. Surveillance of HIV prevalence in key populations often occurs as independent studies with no established mechanism for collating such information at the European level.AimWe assessed HIV prevalence in MSM, PWID, prisoners, sex workers, and transgender people in the 30 European Union/European Economic Area countries and the United Kingdom.MethodsWe conducted a systematic literature review of peer-reviewed studies published during 2009-19, by searching PubMed, Embase and the Cochrane Library. Data are presented in forest plots by country, as simple prevalence or pooled across multiple studies.ResultsEighty-seven country- and population-specific studies were identified from 23 countries. The highest number of studies, and the largest variation in HIV prevalence, were identified for MSM, ranging from 2.4-29.0% (19 countries) and PWID, from 0.0-59.5% (13 countries). Prevalence ranged from 0.0-15.6% in prisoners (nine countries), 1.1-8.5% in sex workers (five countries) and was 10.9% in transgender people (one country). Individuals belonging to several key population groups had higher prevalence.ConclusionThis review demonstrates that HIV prevalence is highly diverse across population groups and countries. People belonging to multiple key population groups are particularly vulnerable; however, more studies are needed, particularly for sex workers, transgender people and people with multiple risks.

Can HIV epidemics among MSM be eliminated through participation in preexposure prophylaxis rollouts?

OBJECTIVE: To study the conditions under which preexposure prophylaxis (PrEP) coverage can eliminate HIV among MSM in the Paris region. DESIGN: Mathematical modeling. METHODS: We propose an innovative approach, combining a transmission model with a game-theoretic model, for decision-making about PrEP use. Individuals at high risk of HIV infection decide to use PrEP, depending on their perceived risk of infection and the relative cost of using PrEP versus antiretroviral treatment (ART), which includes monetary and/or nonmonetary aspects, such as price and access model of PrEP, consequences of being infected and lifelong ART. RESULTS: If individuals assessed correctly their infection risk, and the cost of using PrEP were sufficiently low, then the PrEP rollout could lead to elimination. Specifically, assuming 86% PrEP effectiveness, as observed in two clinical trials, a minimum PrEP coverage of 55% [95% confidence interval (CI) 43-64%] among high-risk MSM would achieve elimination in the Paris region. A complete condom drop by MSM using PrEP slightly increases the minimum PrEP coverage required for elimination, by ∼1%, whereas underestimation of their own HIV infection risk would require PrEP programs reduce the cost of using PrEP by a factor ∼2 to achieve elimination. CONCLUSION: Elimination conditions are not yet met in the Paris region, where at most 47% of high-risk MSM were using PrEP as of mid-2019. Further lowering the cost of PrEP and promoting a fair perception of HIV risk are required and should be maintained in the long-run, to maintain elimination status.

Impact of test-and-treat and risk reduction strategies on HCV transmission among MSM living with HIV in France: a modelling approach.

OBJECTIVE: Since the early 2000s, there has been an epidemic of HCV occurring among men who have sex with men (MSM) living with HIV, mainly associated with high-risk sexual and drug-related behaviours. Early HCV diagnosis and treatment, and behavioural risk-reduction, may be effective to eliminate HCV among MSM living with HIV. DESIGN: We developed a deterministic dynamic compartmental model to simulate the impact of test-and-treat and risk-reduction strategies on HCV epidemic (particularly on incidence and prevalence) among MSM living with HIV in France. We accounted for HIV and HCV cascades of care, HCV natural history and heterogeneity in HCV risk behaviours. The model was calibrated to primary HCV incidence observed between 2014 and 2017 among MSM living with HIV in care (ANRS CO4-French hospital database on HIV (FHDH)). RESULTS: With current French practices (annual HCV screening and immediate treatment), total HCV incidence would fall by 70%, from 0.82/100 person-years in 2015 to 0.24/100 person-years in 2030. It would decrease to 0.19/100 person-years in 2030 with more frequent screening and to 0.19 (0.12)/100 person-years in 2030 with a 20% (50%) risk-reduction. When combining screening every 3 months with a 50% risk-reduction, HCV incidence would be 0.11/100 person-years in 2030, allowing to get close to the WHO target (90% reduction from 2015 to 2030). Similarly, HCV prevalence would decrease from 2.79% in 2015 to 0.48% in 2030 (vs 0.71% with current practices). CONCLUSION: Combining test-and-treat and risk-reduction strategies could have a marked impact on the HCV epidemic, paving the way to HCV elimination among MSM living with HIV.

Revealing HIV epidemic dynamics and contrasting responses in two WHO Eastern European countries: insights from modeling and data triangulation.

OBJECTIVES: In the early 2000s, Estonia and Latvia experienced a rapidly growing HIV epidemic among people who inject drugs (PWID), and had, with Russia, the highest diagnosis rates in Europe. Understanding epidemic dynamics in both countries and how responses to HIV impacted them is essential to ending injection-driven epidemics. DESIGN: Statistical modeling, programmatic data collection, and triangulation. METHODS: Data on newly diagnosed HIV cases were used in a back-calculation model to estimate, for each country, trends in HIV incidence, time to diagnosis, and undiagnosed infections. Modeled estimates were then triangulated with programmatic data on harm reduction services, HIV testing, and ART. RESULTS: From 2007 to 2016, HIV incidence decreased in Estonia by 61% overall, for all exposure groups, and particularly for male PWID (97%), except men who have sex with men, where it increased by 418%. In Latvia, it increased by 72% overall. Median time to diagnosis decreased for male PWID in Estonia, from 3.5 to 2.6 years, but not in Latvia. In 2016, most new and undiagnosed infections, ∼50% in Latvia and ∼75% in Estonia, affected individuals reporting heterosexual transmission, showing a gradual shift toward heterosexual route as the main reported exposure mode. Coverage of services had been higher in Estonia; for example, by 2016, for PWID, there were >200 needles and syringes distributed per PWID annually, and HIV testing and ART coverage reached ∼50% and 76%, respectively, in Estonia, against respectively less than 100%, 10% and 27% in Latvia. CONCLUSIONS: Estonia has turned the tide of its epidemic - large scale-up of prevention and care programs probably contributed to it - whereas in Latvia it remains very active.

Human Immunodeficiency Virus Continuum of Care in 11 European Union Countries at the End of 2016 Overall and by Key Population: Have We Made Progress?

BACKGROUND: High uptake of antiretroviral treatment (ART) is essential to reduce human immunodeficiency virus (HIV) transmission and related mortality; however, gaps in care exist. We aimed to construct the continuum of HIV care (CoC) in 2016 in 11 European Union (EU) countries, overall and by key population and sex. To estimate progress toward the Joint United Nations Programme on HIV/AIDS (UNAIDS) 90-90-90 target, we compared 2016 to 2013 estimates for the same countries, representing 73% of the population in the region. METHODS: A CoC with the following 4 stages was constructed: number of people living with HIV (PLHIV); proportion of PLHIV diagnosed; proportion of those diagnosed who ever initiated ART; and proportion of those ever treated who achieved viral suppression at their last visit. RESULTS: We estimated that 87% of PLHIV were diagnosed; 92% of those diagnosed had ever initiated ART; and 91% of those ever on ART, or 73% of all PLHIV, were virally suppressed. Corresponding figures for men having sex with men were: 86%, 93%, 93%, 74%; for people who inject drugs: 94%, 88%, 85%, 70%; and for heterosexuals: 86%, 92%, 91%, 72%. The proportion suppressed of all PLHIV ranged from 59% to 86% across countries. CONCLUSIONS: The EU is close to the 90-90-90 target and achieved the UNAIDS target of 73% of all PLHIV virally suppressed, significant progress since 2013 when 60% of all PLHIV were virally suppressed. Strengthening of testing programs and treatment support, along with prevention interventions, are needed to achieve HIV epidemic control.

Summarizing the results and methods of the 2019 Joint United Nations Programme on HIV/AIDS HIV estimates.

: UNAIDS and other partners provide support to countries to develop estimates of HIV and related indicators on an annual basis. These estimates are used to monitor epidemic trends, guide program planning and resource allocation, and inform policy decision-making. The collection of articles in this AIDS supplement provide the headline results for the 2019 UNAIDS estimates and describe the new developments in the methods used to produce these estimates.

Estimates of the HIV undiagnosed population in Belgium reveals higher prevalence for MSM with foreign nationality and for geographic areas hosting big cities.

INTRODUCTION: Increasing our knowledge on geographic areas and key populations most affected by HIV is essential to improve prevention and care and to ensure a more focused HIV response. Here, we estimated the prevalence of undiagnosed HIV infections in Belgium and its distribution across geographic areas and exposure groups. METHODS: We used surveillance data on newly diagnosed HIV cases and a previously developed back-calculation model to estimate number and prevalence rates (per 10000) of undiagnosed HIV infections by exposure group at national and subnational levels. Belgium consists of three regions: Flanders, Brussels-Capital Region and Wallonia. We produced estimates for Brussels-Capital Region and Wallonia. For Flanders, we produced estimates for two sub-regional areas: the province of Antwerp and the other provinces, because Antwerp is the second largest city after Brussels. Population sizes were determined using data from the Belgian Statistical Office and surveys on sexual behaviour and drug use. RESULTS: In Belgium, in 2015, an estimated 2818 (95% confidence interval: 2494 to 3208) individuals were living with undiagnosed HIV, that is, 15% of individuals living with HIV. The Brussels-Capital Region and the province of Antwerp, which host the two biggest cities, accounted for ~60% of the undiagnosed infections, and had the highest undiagnosed prevalence rates per 10000: 12.0 (9.4 to 15.3) and 7.4 (5.6 to 9.8) respectively. Individuals with foreign nationality accounted for 56% of the total number of undiagnosed infections, and were the most affected populations in all areas in terms of undiagnosed prevalence rates. Specifically, men who have sex with men (MSM) with non-European nationality were the most affected population in the province of Antwerp (853.4 (408.2 to 1641.9) undiagnosed infections per 10000), the Brussels-Capital Region (543.9 (289.1 to 1019.1)), and the other provinces of Flanders (691.7 (235.5 to 1442.2)), while in Wallonia, it was heterosexual women with Sub-Saharan African nationality (132.2 (90.6 to 178.5)). CONCLUSIONS: Geographic areas hosting the biggest cities in Belgium accounted for the vast majority of undiagnosed HIV infections and individuals with foreign nationality were the most affected, especially MSM with non-European nationality. This should be accounted for when tailoring prevention and testing programs. Furthermore, MSM with foreign nationality require more attention in Belgium, and certainly more generally in Europe.

Are European HIV cohort data within EuroCoord representative of the diagnosed HIV population?

OBJECTIVE: HIV cohorts are an important source of clinical data for informing public health policies and programmes. However, the generalizability of cohort findings to the wider population of people diagnosed with HIV in each country remains unclear. In this work, we assessed the representativeness of six large national HIV cohorts within Europe. DESIGN AND METHODS: Individual-level cohort data were provided from national cohorts in France, Germany, Greece, Italy, Spain and the United Kingdom. Analysis focused on new HIV diagnoses reported to The European Surveillance System (TESSy) during three time periods (2000-2004, 2005-2009 and 2010-2013), to allow for temporal changes. Cohort and TESSy records were matched and compared by age, sex, transmission mode, region of origin and CD4+ cell count at diagnosis. The probability of being included in each cohort given demographic characteristics was estimated and used to generate weights inversely proportional to the probability of being included. RESULTS: Participating cohorts were generally representative of the national HIV-diagnosed population submitted to TESSy. However, people who inject drugs, those born in a country other than that reporting the data, those with low CD4 cell counts at diagnosis, and those more than 55 years were generally underrepresented in the cohorts examined. CONCLUSION: These European cohorts capture a representative sample of the HIV-diagnosed populations in each country; however some groups may be underrepresented.

HIV testing within general practices in Europe: a mixed-methods systematic review.

BACKGROUND: Late diagnosis of HIV infection remains a key challenge in Europe. It is acknowledged that general practitioners (GPs) may contribute greatly to early case finding, yet there is evidence that many diagnostic opportunities are being missed. To further promote HIV testing in primary care and to increase the utility of available research, the existing evidence has been synthesised in a systematic review adhering to the PRISMA guidelines. METHODS: The databases PubMed, Scopus and Embase were searched for the period 2006-2017. Two authors judged independently on the eligibility of studies. Through a mixed-methods systematic review of 29 studies, we provide a description of HIV testing in general practices in Europe, including barriers and facilitators. RESULTS: The findings of the study show that although various approaches to target patients are used by GPs, most tests are still carried out based on the patient's request. Several barriers obstruct HIV testing in general practice. Included are a lack of communication skills on sexual health, lack of knowledge about HIV testing recommendations and epidemic specificities, difficulties with using the complete list of clinical HIV indicator diseases and lack of experience in delivering and communicating test results. The findings also suggest that the provision of specific training, practical tools and promotion programmes has an impact on the testing performance of GPs. CONCLUSIONS: GPs could have an increased role in provider-initiated HIV-testing for early case finding. To achieve this objective, solutions to the reported barriers should be identified and testing criteria adapted to primary healthcare defined. Providing guidance and training to better identify priority groups for HIV testing, as well as information on the HIV epidemic's characteristics, will be fundamental to increasing awareness and testing by GPs.

Brief Report: Per Sex-Act Risk of HIV Transmission Under Antiretroviral Treatment: A Data-Driven Approach.

BACKGROUND: Before the completion of HPTN 052, PARTNER, and Opposites Attract studies, data were lacking to directly estimate HIV transmission risk under effective combined antiretroviral treatment (cART). Rather, estimates were obtained by extrapolating a dose-response relationship between viral load and risk of HIV transmission, observed among untreated individuals, to treated individuals. Presently, data have accumulated from 9 clinical studies for a direct validation of this extrapolation. METHODS: Using estimates of per sex-act risk of HIV transmission on effective cART obtained by extrapolation, sexual behavior data, and a simple mathematical model, we estimated the number of seroconversions that should have been observed in HIV-serodiscordant couples where the HIV-positive partner was on cART across the 9 studies. We compared this with the number of seroconversions actually observed. Next, we directly estimated the risk of HIV transmission on effective cART, using Bayesian statistics to combine all available data. RESULTS: We found that at least 4.7 (uncertainty bounds: 1.7-12.6) and 35.1 (uncertainty bounds: 13.2-92.0) seroconversions should have been observed among, respectively, heterosexual and men who have sex with men (MSM) serodiscordant couples. This is not validated by observations across the studies, which reported at most 1 seroconversion among heterosexual couples and 0 for MSM. Combining all available data, we found that the maximum per sex-act risk of HIV transmission under effective cART is 3.9:100,000 for heterosexuals and 4.4:100,000 for MSM. CONCLUSIONS: Data have accumulated to render obsolete estimates of the risk of HIV transmission on cART obtained by extrapolation. Direct estimates are substantially lower and should be used in practice.

Substantial Heterogeneity in Progress Toward Reaching the 90-90-90 HIV Target in the WHO European Region.

BACKGROUND: Achieving the UNAIDS 90-90-90 target by 2020 is expected to end the HIV epidemic by 2030. We report on progress in the WHO European Region in meeting this target. METHODS: The European Centre for Disease Prevention and Control (ECDC) sent questionnaires to 55 countries in 2016. We report estimates for 4 stages of the continuum of HIV care (living with HIV, diagnosed, treated, and virally suppressed), corresponding to the Joint United Nations Programme on HIV and AIDS (UNAIDS) target and explore differences by subregion and challenges with reporting data. FINDINGS: Forty-four countries provided data for ≥1 stage, and 29 for all 4 stages. Estimated HIV prevalence was 0.19% (range 0.02%-0.84%, n = 37 countries providing stage 1 data). The proportion diagnosed of people living with HIV ranged from 38% to 98% (n = 37 reporting number of people living with HIV and diagnosed). The proportion on ART of those diagnosed ranged from 27% to 96% (n = 40 reporting numbers diagnosed and treated), and viral suppression rates ranged from 32% to 97% (n = 31 providing numbers treated and virally suppressed). The overall continuum of care estimate for 29 countries with complete data was 81-84-88, which differed by subregion: 84-88-90, 84-69-62, and 57-45-57 for the western, central, and eastern subregions, respectively. Challenges in reporting data included absence of a single data source for all stages, shortage of expertise, and lack of financial and human resources. CONCLUSIONS: There is an urgent need to strengthen HIV testing programs throughout Europe, particularly in the eastern subregion, and to remove constraints hampering access to testing and care. Recent changes to treatment guidelines should help reduce the numbers diagnosed not treated.

Revealing geographical and population heterogeneity in HIV incidence, undiagnosed HIV prevalence and time to diagnosis to improve prevention and care: estimates for France.

INTRODUCTION: To close gaps in HIV prevention and care, knowledge about locations and populations most affected by HIV is essential. Here, we provide subnational and sub-population estimates of three key HIV epidemiological indicators, which have been unavailable for most settings. METHODS: We used surveillance data on newly diagnosed HIV cases from 2004 to 2014 and back-calculation modelling to estimate in France, at national and subnational levels, by exposure group and country of birth: the numbers of new HIV infections, the times to diagnosis, the numbers of undiagnosed HIV infections. The denominators used for rate calculations at national and subnational levels were based on population size (aged 18 to 64) estimates produced by the French National Institute of Statistics and Economic Studies and the latest national surveys on sexual behaviour and drug use. RESULTS: We estimated that, in 2014, national HIV incidence was 0.17‰ (95% confidence intervals (CI): 0.16 to 0.18) or 6607 (95% CI: 6057 to 7196) adults, undiagnosed HIV prevalence was 0.64‰ (95% CI: 0.57 to 0.70) or 24,197 (95% CI: 22,296 to 25,944) adults and median time to diagnosis over the 2011 to 2014 period was 3.3 years (interquartile range: 1.2 to 5.7). Three mainland regions, including the Paris region, out of the 27 French regions accounted for 56% of the total number of new and undiagnosed infections. Incidence and undiagnosed prevalence rates were 2- to 10-fold higher than the national rates in three overseas regions and in the Paris region (p-values < 0.001). Rates of incidence and undiagnosed prevalence were higher than the national rates for the following populations (p-values < 0.001): born-abroad men who have sex with men (MSM) (respectively, 108- and 78-fold), French-born MSM (62- and 44-fold), born-abroad persons who inject drugs (14- and 18-fold), sub-Saharan African-born heterosexuals (women 15- and 15-fold, men 11- and 13-fold). Importantly, affected populations varied from one region to another, and in regions apparently less impacted by HIV, some populations could be as impacted as those living in most impacted regions. CONCLUSIONS: In France, some regions and populations have been most impacted by HIV. Subnational and sub-population estimates of key indicators are not only essential to adapt, design implement and evaluate tailored HIV interventions in France, but also elsewhere where similar heterogeneity is likely to exist.

Prevention of treatable infectious diseases: A game-theoretic approach.

We model outcomes of voluntary prevention using an imperfect vaccine, which confers protection only to a fraction of vaccinees for a limited duration. Our mathematical model combines a single-player game for the individual-level decision to get vaccinated, and a compartmental model for the epidemic dynamics. Mathematical analysis yields a characterization for the effective vaccination coverage, as a function of the relative cost of prevention versus treatment; note that cost may involve monetary as well as non-monetary aspects. Three behaviors are possible. First, the relative cost may be too high, so individuals do not get vaccinated. Second, the relative cost may be moderate, such that some individuals get vaccinated and voluntary vaccination alleviates the epidemic. In this case, the vaccination coverage grows steadily with decreasing relative cost of vaccination versus treatment. Unlike previous studies, we find a third case where relative cost is sufficiently low so epidemics may be averted through the use of prevention, even for an imperfect vaccine. However, we also found that disease elimination is only temporary-as no equilibrium exists for the individual strategy in this third case-and, with increasing perceived cost of vaccination versus treatment, the situation may be reversed toward the epidemic edge, where the effective reproductive number is 1. Thus, maintaining relative cost sufficiently low will be the main challenge to maintain disease elimination. Furthermore, our model offers insight on vaccine parameters, which are otherwise difficult to estimate. We apply our findings to the epidemiology of measles.