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.

Psychosocial factors involved in the very rare 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.

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.

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

Background

In 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.

Aim

We 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.

Methods

We 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.

Results

Eighty-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.

Conclusion

This 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.

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.

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.

[HIV prevention with PrEP: Challenges and prospects]

Pre-exposure prophlaxis (PrEP) is the use of antiretroviral drugs by uninfected people to prevent human immunodeficiency virus (HIV) infection. PrEP is used by people who are at substantial risk of being exposed to HIV. Numerous clinical trials have confirmed its effectiveness in reducing HIV acquisition and PrEP has been approved and allowed in several countries including France. However, PrEP uptake remains low as concerns about increase in sexual risk behaviour with PrEP use in the wake of a growing epidemic of sexually transmitted infections, and fear of drug resistance have been expressed. As a result, the difference between the proportion of people on PrEP and the proportion of people who would be very likely to use PrEP if they could access it -otherwise known as the PrEP gap- remains high. Nowadays, studies continue to explore long-term effects of PrEP as well as expand the array of available technologies and regimens.

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.

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.

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.

Risk of HIV transmission during combined ART initiation for HIV-infected persons with severe immunosuppression

Background

Individuals presenting for care with severe immunosuppression typically have high plasma HIV viral load (pVL) and may transmit HIV before and after initiation of combination antiretroviral therapies (cART).

Patients and methods

Using risk equations and data collected in the IMEA 040 DATA trial on sexual behaviour and pVL level of 84 HIV-infected patients (23 women), we estimated monthly rates of HIV transmission for each virologically unsuppressed participant (pVL >50 copies/mL) who reported sex with HIV-negative or unknown serostatus (HNUS) partners at cART initiation, 24 weeks (W24) and W48 after; rates were considered negligible for other participants.

Results

At cART initiation, median pVL was 5.4 log10 copies/mL. The percentage of virologically unsuppressed patients decreased, from 100% at cART initiation to 27% (95% CI 16%-43%) for heterosexuals and 8% (95% CI 2%-22%) for MSM at W48 (P < 0.001). The percentage of patients reporting sex with HNUS partners increased between cART initiation and W48, from 23% (95% CI 10%-42%) to 42% (95% CI 25%-61%) for heterosexuals (P = 0.042) and from 41% (95% CI 21%-64%) to 73% (95% CI 52%-88%) for MSM (P = 0.004). Median monthly HIV transmission rates were 0.0540 (IQR 0.0339-0.0742) for MSM and 0.0018 (IQR 0.0014-0.0191) for heterosexuals at cART initiation, and were reduced by 95% (95% CI 87%-100%) for heterosexuals and 98% (95% CI 95%-100%) for MSM as early as W24.

Conclusions

Risk of onward transmission for severely immunosuppressed individuals is high before and within the first weeks of cART, and persists, at a substantially reduced level, beyond 24 weeks of cART for some individuals. Earlier cART and protecting HIV-negative partners until full viral suppression is achieved could reduce HIV transmission.

Monitoring the HIV continuum of care in key populations across Europe and Central Asia

OBJECTIVES

The aim of the study was to measure and compare national continuum of HIV care estimates in Europe and Central Asia in three key subpopulations: men who have sex with men (MSM), people who inject drugs (PWID) and migrants.

METHODS

Responses to a 2016 European Centre for Disease Prevention and Control (ECDC) survey of 55 European and Central Asian countries were used to describe continuums of HIV care for the subpopulations. Data were analysed using three frameworks: Joint United Nations Programme on HIV/AIDS (UNAIDS) 90-90-90 targets; breakpoint analysis identifying reductions between adjacent continuum stages; quadrant analysis categorizing countries using 90% cut-offs for continuum stages.

RESULTS

Overall, 29 of 48 countries reported national data for all HIV continuum stages (numbers living with HIV, diagnosed, receiving treatment and virally suppressed). Six countries reported all stages for MSM, seven for PWID and two for migrants. Thirty-one countries did not report data for MSM (34 for PWID and 41 for migrants). In countries that provided key-population data, overall, 63%, 40% and 41% of MSM, PWID and migrants living with HIV were virally suppressed, respectively (compared with 68%, 65% and 68% nationally, for countries reporting key-population data). Variation was observed between countries, with higher outcomes in subpopulations in Western Europe compared with Eastern Europe and Central Asia.

CONCLUSIONS

Few reporting countries can produce the continuum of HIV care for the three key populations. Where data are available, differences exist in outcomes between the general and key populations. While MSM broadly mirror national outcomes (in the West), PWID and migrants experience poorer treatment and viral suppression. Countries must develop continuum measures for key populations to identify and address inequalities.

The Human Immunodeficiency Virus Continuum of Care in European Union Countries in 2013: Data and Challenges

BACKGROUND.

The Joint United Nations Programme on HIV/AIDS (UNAIDS) has set a "90-90-90" target to curb the human immunodeficiency virus (HIV) epidemic by 2020, but methods used to assess whether countries have reached this target are not standardized, hindering comparisons.

METHODS.

Through a collaboration formed by the European Centre for Disease Prevention and Control (ECDC) with European HIV cohorts and surveillance agencies, we constructed a standardized, 4-stage continuum of HIV care for 11 European Union countries for 2013. Stages were defined as (1) number of people living with HIV in the country by end of 2013; (2) proportion of stage 1 ever diagnosed; (3) proportion of stage 2 that ever initiated ART; and (4) proportion of stage 3 who became virally suppressed (≤200 copies/mL). Case surveillance data were used primarily to derive stages 1 (using back-calculation models) and 2, and cohort data for stages 3 and 4.

RESULTS.

In 2013, 674500 people in the 11 countries were estimated to be living with HIV, ranging from 5500 to 153400 in each country. Overall HIV prevalence was 0.22% (range, 0.09%-0.36%). Overall proportions of each previous stage were 84% diagnosed, 84% on ART, and 85% virally suppressed (60% of people living with HIV). Two countries achieved ≥90% for all stages, and more than half had reached ≥90% for at least 1 stage.

CONCLUSIONS.

European Union countries are nearing the 90-90-90 target. Reducing the proportion undiagnosed remains the greatest barrier to achieving this target, suggesting that further efforts are needed to improve HIV testing rates. Standardizing methods to derive comparable continuums of care remains a challenge.

Sub-Saharan African migrants living with HIV acquired after migration, France, ANRS PARCOURS study, 2012 to 2013

We estimated the proportion of migrants from sub-Saharan Africa who acquired human immunodeficiency virus (HIV) while living in France. Life-event and clinical information was collected in 2012 and 2013 from a random sample of HIV-infected outpatients born in sub-Saharan Africa and living in the Paris region. We assumed HIV infection in France if at least one of the following was fulfilled: (i) HIV diagnosis at least 11 years after arrival in France, (ii) at least one negative HIV test in France, (iii) sexual debut after arrival in France. Otherwise, time of HIV infection was based on statistical modelling of first CD4(+) T-cell count; infection in France was assumed if more than 50% (median scenario) or more than 95% (conservative scenario) of modelled infection times occurred after migration. We estimated that 49% of 898 HIV-infected adults born in sub-Saharan Africa (95% confidence interval (CI): 45-53) in the median and 35% (95% CI: 31-39) in the conservative scenario acquired HIV while living in France. This proportion was higher in men than women (44% (95% CI: 37-51) vs 30% (95% CI: 25-35); conservative scenario) and increased with length of stay in France. These high proportions highlight the need for improved HIV policies targeting migrants.

New indicators for delay in initiation of antiretroviral treatment: estimates for Cameroon

Objective

To propose two new indicators for monitoring access to antiretroviral treatment (ART) for human immunodeficiency virus (HIV); (i) the time from HIV seroconversion to ART initiation, and (ii) the time from ART eligibility to initiation, referred to as delay in ART initiation. To estimate values of these indicators in Cameroon.

Methods

We used linear regression to model the natural decline in CD4+ T-lymphocyte (CD4+ cell) numbers in HIV-infected individuals over time. The model was fitted using data from a cohort of 351 people in Côte d’Ivoire. We used the model to estimate the time from seroconversion to ART initiation and the delay in ART initiation in a representative sample of 4154 HIV-infected people who started ART in Cameroon between 2007 and 2010.

Findings

In Cameroon, the median CD4+ cell counts at ART initiation increased from 140 cells/μl (interquartile range, IQR: 66 to 210) in 2007–2009 to 163 cells/μl (IQR: 73 to 260) in 2010. The estimated average time from seroconversion to ART initiation decreased from 10.4 years (95% confidence interval, CI: 10.3 to 10.5) to 9.8 years (95% CI: 9.6 to 10.0). Delay in ART initiation increased from 3.4 years (95% CI: 3.1 to 3.7) to 5.8 years (95% CI: 5.6 to 6.2).

Conclusion

The estimated time to initiate ART and the delay in ART initiation indicate that progress in Cameroon is insufficient. These indicators should help monitor whether public health interventions to accelerate ART initiation are successful.

[Overview of the HIV epidemics in France and worldwide ]

In 2012, an estimated 35.3 million people were living with HIV worldwide and new HIV infections (2.3 million) were down 20% compared to 2001. Over the past year, tremendous progress has been achieved in the fight against HIV, including expanded access to antiretroviral therapy (ART) and services to prevent mother-to-child transmission of HIV. However, progress is uneven. The regions most affected by HIV, Sub-Saharan Africa and the Caribbean, have seen a significant increase in ART coverage and drop in new HIV infections, while for other regions, such as the Middle East, North Africa, Eastern Europe and Central Asia, HIV trends have become worrisome. In many high-income countries, such as France, HIV epidemics are far from over, especially among men who have sex with men, where the HIV epidemic remains uncontrolled. Global, rapid scale-up of ART programs significantly decreased HIV/AIDS-related morbidity and mortality but has not been successful in preventing late HIV diagnosis. Reducing the time interval between HIV infection and diagnosis remains one of the biggest challenges that all HIV-affected countries have to face to further reduce HIV/AIDS-related mortality and control the HIV epidemic.

Heterosexual risk of HIV transmission per sexual act under combined antiretroviral therapy: systematic review and bayesian modeling

BACKGROUND

Although essential for patient counseling and quality of life of human immunodeficiency virus (HIV)-infected individuals, the risk of HIV transmission during 1 unprotected sex act with an HIV-infected person under combination antiretroviral therapy (cART) remains unknown.

METHODS

We reviewed systematically the literature for studies on HIV transmission among heterosexual HIV-serodiscordant couples, where the infected partner was on cART, with regular virological monitoring, reporting on condom use and sexual activity. We used Bayesian statistics to combine data from selected studies, to investigate the per-act risk of HIV transmission through unprotected sex with an HIV-infected person on cART for >6 months.

RESULTS

At most, 1 HIV transmission, over an estimated 113 480 sex acts, of which 17% were not condom protected, was reported within 1672 HIV-serodiscordant couples where the index partner had been treated for >6 months. Data were insufficient to determine whether the reported transmission occurred before or after 6 months of cART. We estimated the upper-bound per-act risk of HIV transmission at either 8.7 or 13:100 000, depending on whether the transmission occurred before or after 6 months of cART. These estimates applied whether or not index partners were virally suppressed. Estimating an upper-bound risk <1:100 000 would require observing no HIV transmission while collecting >12 times the available amount of data.

CONCLUSIONS

Available data do not support zero risk of HIV transmission under cART. The per-act risk of HIV transmission through unprotected sex with HIV-infected individuals on cART in comprehensive care for >6 months (whether or not virally suppressed) is <13:100 000. Estimating a 10-fold lower upper-bound risk may be unfeasible due to high condom use among HIV-serodiscordant couples in most research studies.

Factors associated with late antiretroviral therapy initiation in Cameroon: a representative multilevel analysis

OBJECTIVES

Many people living with HIV/AIDS in resource-limited settings begin antiretroviral therapy (ART) at low CD4 counts. Here, we investigated the simultaneous effect of individual-, facility- and regional-level factors on late ART initiation.

METHODS

We conducted a survey in a nationally representative sample of 55 HIV treatment facilities in Cameroon. Medical records of 4935 patients >15 years of age who initiated ART in the month of October during the period 2007-10 were reviewed to gather individual characteristics. Late ART initiation was defined as CD4 count ≤ 100 cells/mm(3). Facility- and regional-level characteristics were also collected. Two-level regression logistic models were used to identify factors associated with late ART initiation.

RESULTS

Late ART initiation was associated with being a male younger than 45 years versus female younger than 45 years [adjusted OR (AOR) = 1.5, 95% CI: 1.3-1.7] and initiating ART in the period 2007-09 versus 2010 (AOR = 1.2, 95% CI: 1.0-1.4). Late initiation was more likely in central than in district hospitals (AOR = 1.3, 95% CI: 1.1-1.6) and in hospitals without a mother-to-child transmission programme (AOR = 1.9, 95% CI: 1.3-2.8). Living in a region with a higher comprehensive knowledge of HIV/AIDS was associated with not initiating ART late (AOR = 0.8, 95% CI: 0.6-1.0).

CONCLUSIONS

This study shows that risk factors associated with late ART initiation operate at multiple levels and that multilevel interventions are therefore necessary to promote earlier HIV testing and treatment.

Modeling dynamic interactions between pre-exposure prophylaxis interventions & treatment programs: predicting HIV transmission & resistance

Clinical trials have recently demonstrated the effectiveness of Pre-Exposure Prophylaxis (PrEP) in preventing HIV infection. Consequently, PrEP may soon be used for epidemic control. We model the dynamic interactions that will occur between treatment programs and potential PrEP interventions in resource-constrained countries. We determine the consequences for HIV transmission and drug resistance. We use response hypersurface modeling to predict the effect of PrEP on decreasing transmission as a function of effectiveness, adherence and coverage. We predict PrEP will increase need for second-line therapies (SLT) for treatment-naïve individuals, but could significantly decrease need for SLT for treatment-experienced individuals. If the rollout of PrEP is carefully planned it could increase the sustainability of treatment programs. If not, need for SLT could increase and the sustainability of treatment programs could be compromised. Our results show the optimal strategy for rolling out PrEP in resource-constrained countries is to begin around the "worst" treatment programs.

HIV, transmitted drug resistance, and the paradox of preexposure prophylaxis

The administration of antiretrovirals before HIV exposure to prevent infection (i.e., preexposure prophylaxis; PrEP) is under evaluation in clinical trials. Because PrEP is based on antiretrovirals, there is considerable concern that it could substantially increase transmitted resistance, particularly in resource-rich countries. Here we use a mathematical model to predict the effect of PrEP interventions on the HIV epidemic in the men-who-have-sex-with-men community in San Francisco. The model is calibrated using Monte Carlo filtering and analyzed by constructing nonlinear response hypersurfaces. We predict PrEP interventions could substantially reduce transmission but significantly increase the proportion of new infections caused by resistant strains. Two mechanisms can cause this increase. If risk compensation occurs, the proportion increases due to increasing transmission of resistant strains and decreasing transmission of wild-type strains. If risk behavior remains stable, the increase occurs because of reduced transmission of resistant strains coupled with an even greater reduction in transmission of wild-type strains. We define this as the paradox of PrEP (i.e., resistance appears to be increasing, but is actually decreasing). We determine this paradox is likely to occur if the efficacy of PrEP regimens against wild-type strains is greater than 30% and the relative efficacy against resistant strains is greater than 0.2 but less than the efficacy against wild-type. Our modeling shows, if risk behavior increases, that it is a valid concern that PrEP could significantly increase transmitted resistance. However, if risk behavior remains stable, we find the concern is unfounded and PrEP interventions are likely to decrease transmitted resistance.

Complementary approach of data analysis and modeling to estimate the pattern of the BSE epidemic: the example of France

Clinical surveillance was the only way to detect bovine spongiform encephalopathy (BSE) until July 2000 in France. From the 103 cases identified as such between 1991 and June 2000, we used a back-calculation method to reconstruct the longitudinal trend of BSE infections. Between July 1987 and June 1997, an estimated 51,300 (CI =[24,300-84,700]) cattle were infected in France. The comprehensive surveillance of BSE with rapid tests, set up in France since 2001 at the abattoir and fallen plant, allowed study of the relative exposure of the successive birth cohorts with nonconditional logistic regression models adjusted for possible confounding variables. The results were in agreement with those of the back-calculation model, estimating a decrease of the BSE exposure from the birth cohort July 1995-June 1996 that matched with the decrease of the infection after June 1996. In view of the long incubation period of BSE, it is not possible to precisely assess the impact of any control measure before several years. Modeling was therefore used to estimate prospectively the efficiency of the ban of meat and bone meal extended to all farm species in November 2000. Using parameters about age at infection and incubation time estimated earlier, we assessed the minimum time to first detection if infections still occurred. We have waited up to June 2007 to know if less than 100 infections occurred among French cattle during the 6 months following January 2001.

BSE risk assessment as a basis for updating French screening policy

The current French bovine spongiform encephalopathy (BSE) surveillance system, based on rapid testing of all cattle over 24 months of age and on clinical diagnosis, detects all clinical cases and some preclinical cases of BSE. Several indicators point to a marked shrinkage of the French BSE epidemic in recent years, owing to risk reduction measures. Meat and bone meal, the only known vector of the BSE agent, was banned in feed for all farmed species in November 2000. Thus the surveillance system may be relaxed. The objective of this risk assessment study was to provide information for decisionmakers on the minimum age at which healthy and high-risk cattle now need to be screened with rapid tests. For this purpose, we used the back-calculation method to project the course of the BSE epidemic. We examined the predicted patterns of the number and age distribution of cases of BSE that would be detected by the different existing surveillance streams. Various theoretical sensitivities of rapid tests were explored. Assuming that feed-borne sources of infection no longer exist, and that BSE does not occur spontaneously, our models suggest that it would have been possible to raise the minimum age for rapid tests to 66 months in early 2006, whereas theoretical reasoning, based on the assumption that the total meat and bone meal ban was effective in November 2001, suggests that this age cutoff could only be raised to 48 months in early 2006. These results only apply to cattle born and bred in France. If the situation remains unchanged, the age cutoff could be raised incrementally each year.

Estimating incidence of the French BSE infection using a joint analysis of both asymptomatic and clinical BSE surveillance data

Bovine Spongiform Encephalopathy (BSE) clinical surveillance data were the main source of information to perform back-calculation of BSE infection incidence. Since 2001, systematic BSE screening tests enhanced the clinical surveillance and allowed to detect some preclinical, i.e. asymptomatic, cases of BSE. We propose a method to incorporate additional information provided by screening tests. It was the first time that a back-calculation model was developed for a full BSE clinical surveillance. In the spirit, our approach resembles what it was done in the Acquired Immune Deficiency Syndrome (AIDS) epidemic to incorporate the Human Immunodeficiency Virus (HIV) diagnosis. Nevertheless, in the BSE epidemic, we had to consider different surveillance systems, their peculiarity, and the phenomenon of communicating vessels between these surveillance systems. In addition, both the preclinical sensitivity of tests and the status of BSE cases, asymptomatic or clinical, were not precisely known. We applied the model to the French BSE epidemic in order to obtain an updated estimate of the incidence of BSE infection. Our back-calculation model fitted very well the observed data of each surveillance system. We detected a lengthening of the incubation period and estimated that the number of infections was very small in the late 1990s and zero in July 2001.

How was the French BSE epidemic underestimated?

In a previous study, we showed that estimates of the BSE epidemic in France were censored by cattle mortality and by a lack of diagnosis. Indeed, we estimated that 51 300 cattle were infected by the BSE agent between 1987 and 1997, whereas only 103 clinical BSE cases were detected by the passive surveillance system up to June 2000. The question thus arises as to the part played by each form of censorship in this underestimation. Here, using an updated cattle survival distribution, we estimated that 44 800 cattle were infected by the BSE agent between 1987 and 1997, and that 7100 of them showed clinical signs of BSE up to June 2000, showing the low efficiency of the surveillance system. Moreover, between 2087 and 5980 'infectious' cattle, with clinical or preclinical BSE, entered the human food chain before July 1996, the date of the ban on specified bovine offal.

The unrecognised French BSE epidemic

In France, implementation of systematic screening programs in 2000, as a complement to the mandatory reporting of animals with clinical signs of BSE (passive surveillance), revealed certain limitations of the mandatory system. Indeed, systematic screening showed that some BSE cases were not detected by the clinical surveillance system, implying considerable BSE case under-reporting throughout the epidemic. As the most likely explanation for variant Creutzfeldt-Jakob disease (vCJD) is exposure to the aetiologic agent of BSE, it is essential to reconstruct the French BSE epidemic pattern accounting for this under-reporting. We estimated age- and year-specific incidence rates of BSE by using a back-calculation method. This approach relies on the principle that the number of clinical BSE cases is the consequence of the number of BSE-infected animals after a known incubation time, defined as the time between infection and clinical onset. We generalized this model to take into account epidemiological characteristics of BSE, such as French cattle mortality, BSE case reporting probability, and age-dependent susceptibility and/or exposure to the BSE agent. We confirmed that the average BSE incubation period is five years and that the peak risk of bovine infection occurs between 6 and 12 months of age. The results also showed that the proportion of underreporting is the most influential parameter in the model, and that BSE was substantially underreported until rapid tests were introduced. Indeed, only 103 BSE cases were detected by passive surveillance up to June 2000, while we estimated that there was 301 200 (95% confidence interval (CI) [27 600-837 600]) cattle infected by the BSE agent. Despite uncertainty over the beginning of the epidemic, we showed that the French BSE epidemic in the late 1980s was completely undetected, and only the second wave, after 1990, was observed.