Selection for life-history traits to maximize population growth in an invasive marine species.

Species establishing outside their natural range, negatively impacting local ecosystems, are of increasing global concern. They often display life-history features characteristic for r-selected populations with fast growth and high reproduction rates to achieve positive population growth rates (r) in invaded habitats. Here, we demonstrate substantially earlier maturation at a 2 orders of magnitude lower body mass at first reproduction in invasive compared to native populations of the comb jelly Mnemiopsis leidyi. Empirical results are corroborated by a theoretical model for competing life-history traits that predicts maturation at the smallest possible size to optimize r, while individual lifetime reproductive success (R0 ), optimized in native populations, is near constant over a large range of intermediate maturation sizes. We suggest that high variability in reproductive tactics in native populations is an underappreciated determinant of invasiveness, acting as substrate upon which selection can act during the invasion process.

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.

Impact of environmental covariation in growth and mortality on evolving maturation reaction norms.

Maturation age and size have important fitness consequences through their effects on survival probabilities and body sizes. The evolution of maturation reaction norms in response to environmental covariation in growth and mortality is therefore a key subject of life-history theory. The eco-evolutionary model we present and analyze here incorporates critical features that earlier studies of evolving maturation reaction norms have often neglected: the trade-off between growth and reproduction, source-sink population structure, and population regulation through density-dependent growth and fecundity. We report the following findings. First, the evolutionarily optimal age at maturation can be decomposed into the sum of a density-dependent and a density-independent component. These components measure, respectively, the hypothetical negative age at which an individual's length would be 0 and the delay in maturation relative to this offset. Second, along any growth trajectory, individuals mature earlier when mortality is higher. This allows us to deduce, third, how the shapes of evolutionarily optimal maturation reaction norms depend on the covariation between growth and mortality (positive or negative, linear or curvilinear, and deterministic or probabilistic). Providing eco-evolutionary explanations for many alternative reaction-norm shapes, our results appear to be in good agreement with current empirical knowledge on maturation dynamics.

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.

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.

Looking Beyond the Cascade of HIV Care to End the AIDS Epidemic: Estimation of the Time Interval From HIV Infection to Viral Suppression.

BACKGROUND: Ensuring early universal access to HIV treatment is critical to reach the end of AIDS. The cascade of HIV care has become a critical metric to assess the coverage of treatment and viral suppression, but it does not provide any information on the elapsed times between becoming HIV-infected and reaching viral suppression. METHODS: We estimated the cascade of care, the distribution of times between steps of the care continuum, in France, in 2010, at the national level, overall and by HIV exposure groups, using statistical modelling and large datasets: the national HIV surveillance system, the general social insurance scheme, and the French Hospital Database on HIV. RESULTS: We found that the overall rate of viral suppression was high, with an estimated value of 52% (95% confidence interval: 49 to 54). However, the time intervals from HIV infection to viral suppression were long; overall, the median value was 6.1 years (inter quartile range: 3.6-9.2), and it ranged from ∼5.6 years among men who have sex with men and heterosexual women to 9.6 years among injection drug users. Time lost in achieving viral suppression was mainly due to delays in HIV testing (overall median of 3.4 years), except for injection drug users where it was also due to delayed care entry once diagnosed (∼1 year in median versus <1 month for other groups). CONCLUSIONS: High viral suppression rate can hide large gaps between time of HIV infection and time of viral suppression. Estimates of the flow-time between steps of the care continuum should become priority indicators to identify these gaps and monitor whether interventions are successful in closing them.

Fisheries-induced neutral and adaptive evolution in exploited fish populations and consequences for their adaptive potential.

Fishing may induce neutral and adaptive evolution affecting life-history traits, and molecular evidence has shown that neutral genetic diversity has declined in some exploited populations. Here, we theoretically study the interplay between neutral and adaptive evolution caused by fishing. An individual-based eco-genetic model is devised that includes neutral and functional loci in a realistic ecological setting. In line with theoretical expectations, we find that fishing induces evolution towards slow growth, early maturation at small size and higher reproductive investment. We show, first, that the choice of genetic model (based on either quantitative genetics or gametic inheritance) influences the evolutionary recovery of traits after fishing ceases. Second, we analyse the influence of three factors possibly involved in the lack of evolutionary recovery: the strength of selection, the effect of genetic drift and the loss of adaptive potential. We find that evolutionary recovery is hampered by an association of weak selection differentials with reduced additive genetic variances. Third, the contribution of fisheries-induced selection to the erosion of functional genetic diversity clearly dominates that of genetic drift only for the traits related to maturation. Together, our results highlight the importance of taking into account population genetic variability in predictions of eco-evolutionary dynamics.