Aligning climate scenarios to emissions inventories shifts global benchmarks.

Taking stock of global progress towards achieving the Paris Agreement requires consistently measuring aggregate national actions and pledges against modelled mitigation pathways1. However, national greenhouse gas inventories (NGHGIs) and scientific assessments of anthropogenic emissions follow different accounting conventions for land-based carbon fluxes resulting in a large difference in the present emission estimates2,3, a gap that will evolve over time. Using state-of-the-art methodologies4 and a land carbon-cycle emulator5, we align the Intergovernmental Panel on Climate Change (IPCC)-assessed mitigation pathways with the NGHGIs to make a comparison. We find that the key global mitigation benchmarks become harder to achieve when calculated using the NGHGI conventions, requiring both earlier net-zero CO2 timing and lower cumulative emissions. Furthermore, weakening natural carbon removal processes such as carbon fertilization can mask anthropogenic land-based removal efforts, with the result that land-based carbon fluxes in NGHGIs may ultimately become sources of emissions by 2100. Our results are important for the Global Stocktake6, suggesting that nations will need to increase the collective ambition of their climate targets to remain consistent with the global temperature goals.

Realization of Paris Agreement pledges may limit warming just below 2 °C.

Over the last five years prior to the Glasgow Climate Pact1, 154 Parties have submitted new or updated 2030 mitigation goals in their nationally determined contributions and 76 have put forward longer-term pledges. Quantifications of the pledges before the 2021 United Nations Climate Change Conference (COP26) suggested a less than 50 per cent chance of keeping warming below 2 degrees Celsius2-5. Here we show that warming can be kept just below 2 degrees Celsius if all conditional and unconditional pledges are implemented in full and on time. Peak warming could be limited to 1.9-2.0 degrees Celsius (5%-95% range 1.4-2.8 °C) in the full implementation case-building on a probabilistic characterization of Earth system uncertainties in line with the Working Group I contribution to the Sixth Assessment Report6 of the Intergovernmental Panel on Climate Change (IPCC). We retrospectively project twenty-first-century warming to show how the aggregate level of ambition changed from 2015 to 2021. Our results rely on the extrapolation of time-limited targets beyond 2030 or 2050, characteristics of the IPCC 1.5 °C Special Report (SR1.5) scenario database7 and the full implementation of pledges. More pessimistic assumptions on these factors would lead to higher temperature projections. A second, independent emissions modelling framework projected peak warming of 1.8 degrees Celsius, supporting the finding that realized pledges could limit warming to just below 2 degrees Celsius. Limiting warming not only to 'just below' but to 'well below' 2 degrees Celsius or 1.5 degrees Celsius urgently requires policies and actions to bring about steep emission reductions this decade, aligned with mid-century global net-zero CO2 emissions.

Unextractable fossil fuels in a 1.5 °C world.

Parties to the 2015 Paris Agreement pledged to limit global warming to well below 2 °C and to pursue efforts to limit the temperature increase to 1.5 °C relative to pre-industrial times1. However, fossil fuels continue to dominate the global energy system and a sharp decline in their use must be realized to keep the temperature increase below 1.5 °C (refs. 2-7). Here we use a global energy systems model8 to assess the amount of fossil fuels that would need to be left in the ground, regionally and globally, to allow for a 50 per cent probability of limiting warming to 1.5 °C. By 2050, we find that nearly 60 per cent of oil and fossil methane gas, and 90 per cent of coal must remain unextracted to keep within a 1.5 °C carbon budget. This is a large increase in the unextractable estimates for a 2 °C carbon budget9, particularly for oil, for which an additional 25 per cent of reserves must remain unextracted. Furthermore, we estimate that oil and gas production must decline globally by 3 per cent each year until 2050. This implies that most regions must reach peak production now or during the next decade, rendering many operational and planned fossil fuel projects unviable. We probably present an underestimate of the production changes required, because a greater than 50 per cent probability of limiting warming to 1.5 °C requires more carbon to stay in the ground and because of uncertainties around the timely deployment of negative emission technologies at scale.

Quantification of an efficiency-sovereignty trade-off in climate policy.

The Paris Agreement calls for a cooperative response with the aim of limiting global warming to well below two degrees Celsius above pre-industrial levels while reaffirming the principles of equity and common, but differentiated responsibilities and capabilities1. Although the goal is clear, the approach required to achieve it is not. Cap-and-trade policies using uniform carbon prices could produce cost-effective reductions of global carbon emissions, but tend to impose relatively high mitigation costs on developing and emerging economies. Huge international financial transfers are required to complement cap-and-trade to achieve equal sharing of effort, defined as an equal distribution of mitigation costs as a share of income2,3, and therefore the cap-and-trade policy is often perceived as infringing on national sovereignty2-7. Here we show that a strategy of international financial transfers guided by moderate deviations from uniform carbon pricing could achieve the goal without straining either the economies or sovereignty of nations. We use the integrated assessment model REMIND-MAgPIE to analyse alternative policies: financial transfers in uniform carbon pricing systems, differentiated carbon pricing in the absence of financial transfers, or a hybrid combining financial transfers and differentiated carbon prices. Under uniform carbon prices, a present value of international financial transfers of 4.4 trillion US dollars over the next 80 years to 2100 would be required to equalize effort. By contrast, achieving equal effort without financial transfers requires carbon prices in advanced countries to exceed those in developing countries by a factor of more than 100, leading to efficiency losses of 2.6 trillion US dollars. Hybrid solutions reveal a strongly nonlinear trade-off between cost efficiency and sovereignty: moderate deviations from uniform carbon prices strongly reduce financial transfers at relatively small efficiency losses and moderate financial transfers substantially reduce inefficiencies by narrowing the carbon price spread. We also identify risks and adverse consequences of carbon price differentiation due to market distortions that can undermine environmental sustainability targets8,9. Quantifying the advantages and risks of carbon price differentiation provides insight into climate and sector-specific policy mixes.

Organizational system thinking as a cognitive framework to meet climate targets.

System thinking is a crucial cognitive framework to enable individual pro-environmental behavioral changes. Indeed, a large body of literature has shown a significant and positive association between individuals' system thinking capacities and perceptions of the threat posed by climate change. However, individual behavioral changes play a limited role in addressing climate change compared to large organizations involved in a significantly larger share of economic activities. Do organizations exhibit system thinking capacities? Here, we conjecture that system thinking is a cognitive framework observable at an aggregated group level and, therefore, organizations, not just individuals, can exhibit characteristic levels of system thinking. We conceptualize a definition of organizational system thinking and develop an empirical method to estimate it using a large body of textual data from business organizations. Then, we show that system thinking organizations are more likely to lower emissions and align them with the pathways required to meet the climate targets set by the Paris Agreement. Finally, we discussed the theoretical and policy implication of our study. Overall, our results suggest that system thinking is a relevant organization-level cognitive framework that can help organizations align their emissions with global climate targets.

Naming and shaming as a strategy for enforcing the Paris Agreement: The role of political institutions and public concern.

Enforcement is a challenge for effective international cooperation. In human rights and environmental law, along with many other domains of international cooperation, "naming and shaming" is often used as an enforcement mechanism in the absence of stronger alternatives. Naming and shaming hinges on the ability to identify countries whose efforts are inadequate and effectively shame them toward better behavior. Research on this approach has struggled to identify factors that explain when it influences state behavior in ways that lead to more cooperation. Via survey of a large (N = 910) novel sample of experienced diplomats involved in the design of the Paris Agreement, we find support for the proposition that naming and shaming is most accepted and effective in influencing the behavior of countries that have high-quality political institutions, strong internal concern about climate change, and ambitious and credible international climate commitments. Naming and shaming appears less effective in other countries, so further enforcement mechanisms will be needed for truly global cooperation. We also find that the climate diplomacy experts favor a process of naming and shaming that relies on official intergovernmental actors, in contrast with studies suggesting that NGOs, media, and other private actors are more effective at naming and shaming. We suggest that these tensions-the inability for naming and shaming to work effectively within the countries least motivated for climate action and the preference for namers and shamers that seem least likely to be effective-will become central policy debates around making cooperation on climate change more enforceable.

Assessing the extinction risk of the spontaneous flora in urban tree bases.

As the spatial arrangement of trees planted along streets in cities makes their bases potential ecological corridors for the flora, urban tree bases may be a key contributor to the overall connectivity of the urban ecosystem. However, these tree bases are also a highly fragmented environment in which extinctions are frequent. The goal of this study was to assess the plant species' ability to survive and spread through urban tree bases. To do so, we developed a Bayesian framework to assess the extinction risk of a plant metapopulation using presence/absence data, assuming that the occupancy dynamics was described by a Hidden Markov Model. The novelty of our approach is to take into account the combined effect of low-distance dispersal and the potential presence of a seed bank on the extinction risk. We introduced a metric of the extinction risk and examined its performance over a wide range of metapopulation parameters. We applied our framework to yearly floristic inventories carried out in 1324 tree bases in Paris, France. While local extinction risks were generally high, extinction risks at the street scale varied greatly from one species to another. We identified 10 plant species that could survive and spread through urban tree bases, and three plant traits correlated with the extinction risk at the metapopulation scale: the maximal height, and the beginning and end of the flowering period. Our results suggest that some plant species can use urban tree bases as ecological corridors despite high local extinction risks by forming a seed bank. We also identified other plant traits correlated with the ability to survive in tree bases, related to the action of gardeners. Moreover, our findings demonstrate that our Bayesian estimation framework based on percolation theory has the potential to be extended to more general metapopulations.

Estimating and tracking the remaining carbon budget for stringent climate targets.

Research reported during the past decade has shown that global warming is roughly proportional to the total amount of carbon dioxide released into the atmosphere. This makes it possible to estimate the remaining carbon budget: the total amount of anthropogenic carbon dioxide that can still be emitted into the atmosphere while holding the global average temperature increase to the limit set by the Paris Agreement. However, a wide range of estimates for the remaining carbon budget has been reported, reducing the effectiveness of the remaining carbon budget as a means of setting emission reduction targets that are consistent with the Paris Agreement. Here we present a framework that enables us to track estimates of the remaining carbon budget and to understand how these estimates can improve over time as scientific knowledge advances. We propose that application of this framework may help to reconcile differences between estimates of the remaining carbon budget and may provide a basis for reducing uncertainty in the range of future estimates.

Carbon emissions reductions from Indonesia's moratorium on forest concessions are cost-effective yet contribute little to Paris pledges.

International initiatives for reducing carbon emissions from deforestation and forest degradation (REDD+) could make critical, cost-effective contributions to tropical countries' nationally determined contributions (NDCs). Norway, a key donor of such initiatives, had a REDD+ partnership with Indonesia, offering results-based payments in exchange for emissions reductions calculated against a historical baseline. Central to this partnership was an area-based moratorium on new oil palm, timber, and logging concessions in primary and peatland forests. We evaluate the effectiveness of the moratorium between 2011 and 2018 by applying a matched triple difference strategy to a unique panel dataset. Treated dryland forest inside moratorium areas retained, at most, an average of 0.65% higher forest cover compared to untreated dryland forest outside the moratorium. By contrast, carbon-rich peatland forest was unaffected by the moratorium. Cumulative avoided dryland deforestation from 2011 until 2018 translates into 67.8 million to 86.9 million tons of emissions reductions, implying an effective carbon price below Norway's US$5 per ton price. Based on Norway's price, our estimated cumulative emissions reductions are equivalent to a payment of US$339 million to US$434.5 million. Annually, our estimates suggest a 3 to 4% contribution to Indonesia's NDC commitment of a 29% emissions reduction by 2030. Despite the Indonesia-Norway partnership ending in 2021, reducing emissions from deforestation remains critical for meeting this commitment. Future area-based REDD+ initiatives could build on the moratorium's outcomes by reforming its incentives and institutional arrangements, particularly in peatland forest areas.

Nonreplicating synthetic mRNA vaccines: A journey through the European (Journal of Immunology) history.

The first worldwide article reporting that injections of synthetic nonreplicating mRNA could be used as a vaccine, which originated from a French team located in Paris, was published in the European Journal of Immunology (EJI) in 1993. It relied on work conducted by several research groups in a handful of countries since the 1960s, which put forward the precise description of eukaryotic mRNA and the method to reproduce this molecule in vitro as well as how to transfect it into mammalian cells. Thereafter, the first industrial development of this technology began in Germany in 2000, with the founding of CureVac, which stemmed from another description of a synthetic mRNA vaccine published in EJI in 2000. The first clinical studies investigating mRNA vaccines in humans were performed as collaboration between CureVac and the University of Tübingen in Germany as early as 2003. Finally, the first worldwide approved mRNA vaccine (an anti-COVID-19 vaccine) is based on the mRNA technologies developed by BioNTech since its 2008 foundation in Mainz, Germany, and earlier by the pioneering academic work of its founders. In addition to the past, present, and future of mRNA-based vaccines, the article aims to present the geographical distribution of the early work, how the development of the technology was implemented by several independent and internationally distributed research teams, as well as the controversies on the optimal way to design or formulate and administer mRNA vaccines.

Prospecting for rare earth element (hyper)accumulators in the Paris Herbarium using X-ray fluorescence spectroscopy reveals new distributional and taxon discoveries.

BACKGROUND: Rare earth elements (REEs) are increasingly crucial for modern technologies. Plants could be used as a biogeochemical pathfinder and a tool to extract REEs from deposits. However, a paucity of information on suitable plants for these tasks exists. METHODS: We aimed to discover new REE-(hyper)accumulating plant species by performing an X-ray fluorescence (XRF) survey at the Herbarium of the Muséum national d'Histoire naturelle (MNHN, Paris, France). We selected specific families based on the likelihood of containing REE-hyperaccumulating species, using known taxa that accumulate REEs. A total of 4425 specimens, taken in the two main evolutionary lineages of extant vascular plants, were analysed, including the two fern families Blechnaceae (n = 561) and Gleicheniaceae (n = 1310), and the two flowering plant families Phytolaccaceae (n = 1137) and Juglandaceae (n = 1417). KEY RESULTS: Yttrium (Y) was used as a proxy for REEs for methodological reasons, and a total of 268 specimens belonging to the genera Blechnopsis (n = 149), Dicranopteris (n = 75), Gleichenella (n = 32), Phytolacca (n = 6), Carya (n = 4), Juglans (n = 1) and Sticherus (n = 1) were identified with Y concentrations ranging from the limit of detection (LOD) >49 µg g-1 up to 1424 µg g-1. Subsequently, analysis of fragments of selected specimens by inductively coupled plasma atomic emission spectroscopy (ICP-AES) revealed that this translated to up to 6423 µg total REEs g-1 in Dicranopteris linearis and up to 4278 µg total REEs g-1 in Blechnopsis orientalis which are among the highest values ever recorded for REE hyperaccumulation in plants. It also proved the validity of Y as an indicator for REEs in XRF analysis of herbarium specimens. The presence of manganese (Mn) and zinc (Zn) was also studied by XRF in the selected specimens. Mn was detected in 1440 specimens ranging from the detection limit at 116 µg g-1 up to 3807 µg g-1 whilst Zn was detected in 345 specimens ranging from the detection limit at 77 µg g-1 up to 938 µg g-1. CONCLUSIONS AND IMPLICATIONS: This study led to the discovery of REE accumulation in a range of plant species, substantially higher concentrations in species known to be REE hyperaccumulators, and records of REE hyperaccumulators outside of the well-studied populations in China.

Impacts of Behavioral, Organizational, and Spatial Factors on the Carbon Footprint of Traditional Retail and E-commerce in the Paris Region.

Carbon footprint assessment of retail is necessary to optimize procurement strategies and adopt sustainable shopping habits. However, estimating carbon footprints is a complex task, given the diversity of existing distribution channels. Average values for carbon emissions of "conventional" retail (i.e., purchasing and receiving the product directly at the physical point of sale) found in most studies mask a heterogeneous reality: different retail strategies entail diverse shopping behavior for consumers, as well as varied procurement processes for outlets. In this paper, we propose a methodology to assess greenhouse gas (GHG) impacts of different distribution systems related to the consumption of goods in the Paris Region by coupling traditional transport modeling with a life-cycle assessment (LCA) approach. We model and compare six distribution systems, including five traditional retail formats (hypermarkets, supermarkets, small generalist retail, small food retail, and small nonfood retail) and E-commerce home deliveries. Our model includes warehouse activity, shop and home delivery, shop energy consumption, consumer mobility, and goods packaging. Overall, we conclude that E-commerce emits fewer GHG emissions than retail outlets per kilogram of product purchased. This result is in line with the existing literature on the topic. However, the carbon footprint varies greatly within the case study depending on the characteristics of the logistics procurement processes of outlets, the behavior of shoppers, and spatial characteristics.

The many possible climates from the Paris Agreement's aim of 1.5 °C warming.

The United Nations' Paris Agreement includes the aim of pursuing efforts to limit global warming to only 1.5 °C above pre-industrial levels. However, it is not clear what the resulting climate would look like across the globe and over time. Here we show that trajectories towards a '1.5 °C warmer world' may result in vastly different outcomes at regional scales, owing to variations in the pace and location of climate change and their interactions with society's mitigation, adaptation and vulnerabilities to climate change. Pursuing policies that are considered to be consistent with the 1.5 °C aim will not completely remove the risk of global temperatures being much higher or of some regional extremes reaching dangerous levels for ecosystems and societies over the coming decades.

Gynecological health and uptake of gynecological care after domestic or sexual violence: a qualitative study in an emergency shelter.

BACKGROUND: Domestic and sexual violence have been linked to adverse gynecological and obstetric outcomes. Survivors often find it difficult to verbalize such violence due to feelings of shame and guilt. Vulnerable or socially excluded women are frequently excluded from research, particularly qualitative studies on violence. This study aimed to characterize the perceived impact of domestic or sexual violence on the gynecological health and follow-up among women with complex social situations. METHODS: We analyzed the data following inductive thematic analysis methods. RESULTS: Between April 2022 and January 2023, we conducted 25 semi-structured interviews, lasting on average 90 min (range: 45-180), with women aged between 19 and 52, recruited in an emergency shelter in the Paris area. The women described physical and psychological violence mainly in the domestic sphere, their altered gynecological and mental health and their perception of gynecological care. The levels of uptake of gynecological care were related to the characteristics of the violence and their consequences. The description of gynecological examination was close to the description of coerced marital sexuality which was not considered to be sexual violence. Gynecological examination, likely to trigger embarrassment and discomfort, was always perceived to be necessary and justified, and consent was implied. CONCLUSION: This study can help question the appropriateness of professional practices related to the prevention of violence against women and gynecological examination practices. Any gynecological examination should be carried out within the framework of an equal relationship between caregiver and patient, for the general population and for women with a history of violence. It participates in preventing violence in the context of care, and more widely, in preventing violence against women.

Treatment of Aortoiliac Occlusive Lesions by Aortic Robotic Surgery: Learning Curve and Midterm Outcome.

BACKGROUD: The learning curve and midterm results of aortoiliac occlusive disease (AIOD) revascularization by robot-assisted laparoscopic (RAL) surgery may be known. METHODS: A prospective single-center study was conducted in the vascular surgery department of Georges Pompidou European Hospital (Paris, France). Patients with AIOD treated by RAL from February 2014 to February 2019 were included. Demographic characteristics, past medical history, Trans-Atlantic Inter-Society Consensus (TASC) lesions classifications, mortality, primary and secondary patency, as well as complication rates were collected. Safety was analyzed by the cumulative sum control chart method with a conversion rate of 10%, operative time by cumulative average-time model, and primary and secondary patency by the Kaplan-Meier method. RESULTS: Seventy patients were included, 18 (25.7%) with TASC C lesions and 52 (74.3%) with TASC D lesions. Before discharge, 14 (24.3%) patients had surgical complications. Among them, 10 (14.3%) required at least one reintervention. One (1.4%) patient died during the hospitalization. The learning curve in terms of safety (conversion rate) was 13 cases with an operating time of 220 minutes after 35 patients. During follow-up (median 37 months [21; 49]), 63 patients (91.3%) improved their symptoms, 53 (76.8%) became asymptomatic, and 3 graft limb occlusions occurred. The primary patency at 12, 24, 36, and 48 months was 94%, 92%, 92%, and 92%, respectively, while the secondary patency for the same intervals was 100%, 98.1%, 98.1%, and 98.1%, respectively. CONCLUSIONS: Robotic surgery in AIOD revascularization seems safe and effective; allowing to treat patients with few comorbidities and severe lesions, in a dedicated center experienced in RAL, with excellent patency. Prospective clinical trials should be performed to confirm safety.

The impact of air pollution on the facial skin of Caucasian women using real-life pollutant exposure measurements.

BACKGROUND: To date, studies examining the effect of air pollution on skin characteristics have relied on regional pollution estimates obtained from fixed monitoring sites. Hence, there remains a need to characterize the impact of air pollution in vivo in real-time conditions. We conducted an initial investigation under real-life conditions, with the purpose of characterizing the in vivo impact of various pollutants on the facial skin condition of women living in Paris over a 6-month period. MATERIALS AND METHODS: A smartphone application linked to the Breezometer platform was used to collect participants' individual exposures to pollutants through the recovery of global positioning system (GPS) data over a 6-month period. Daily exposure to fine particulate matter (PM 2.5 µm and PM 10 µm), pollen, and air quality was measured. Facial skin color, roughness, pore, hydration, elasticity, and wrinkle measurements were taken at the end of the 6-month period. Participants' cumulated pollutant exposure over 6 months was calculated. Data were stratified into two groups (lower vs. higher pollutant exposure) for each pollutant. RESULTS: 156 women (20-60 years-old) were recruited, with 124 women completing the study. Higher PM 2.5 µm exposure was associated with altered skin color and increased roughness under the eye. Higher PM 10 µm exposure with increased wrinkles and roughness under the eye, increased pore appearance, and decreased skin hydration. Exposure to poorer air quality was linked with increased forehead wrinkles and decreased skin elasticity, while higher pollen exposure increased skin roughness and crow's feet. CONCLUSION: This study suggests a potential correlation between air pollution and facial skin in real-life conditions. Prolonged exposure to PM, gases, and pollen may be linked to clinical signs of skin ageing. This study highlights the importance of longer monitoring over time in real conditions to characterize the effect of pollution on the skin.

Aedes albopictus is a competent vector of five arboviruses affecting human health, greater Paris, France, 2023.

Aedes albopictus collected in 2023 in the greater Paris area (Île-de-France) were experimentally able to transmit five arboviruses: West Nile virus from 3 days post-infection (dpi), chikungunya virus and Usutu virus from 7 dpi, dengue virus and Zika virus from 21 dpi. Given the growing number of imported dengue cases reported in early 2024 in France, surveillance of Ae. albopictus should be reinforced during the Paris Olympic Games in July, when many international visitors including from endemic countries are expected.

Mpox in children and adolescents and contact follow-up in school settings in greater Paris, France, May 2022 to July 2023.

BackgroundDuring the 2022 mpox outbreak in Europe, primarily affecting men who have sex with men, a limited number of cases among children and adolescents were identified. Paediatric cases from outbreaks in endemic countries have been associated with a higher likelihood of severe illness. Detailed clinical case descriptions and interventions in school settings before 2022 are limited.AimTo describe clinical characteristics of mpox cases among children (< 15 years) and adolescents (15-17 years) in the greater Paris area in France, and infection control measures in schools.MethodsWe describe all notified laboratory-confirmed and non-laboratory-confirmed cases among children and adolescents identified from May 2022 to July 2023, including demographic and clinical characterisation and infection control measures in school settings, i.e. contact tracing, contact vaccination, secondary attack rate and post-exposure vaccination uptake.ResultsNineteen cases were notified (13 children, 6 adolescents). Four adolescent cases reported sexual contact before symptom onset. Ten child cases were secondary cases of adult patients; three cases were cryptic, with vesicles on hands, arms and/or legs and one case additionally presented with genitoanal lesions. Five cases attended school during their infectious period, with 160 at-risk contacts identified, and one secondary case. Five at-risk contacts were vaccinated following exposure.ConclusionCases among children and adolescents are infrequent but require a careful approach to identify the source of infection and ensure infection control measures. We advocate a 'contact warning' strategy vs 'contact tracing' in order to prevent alarm and stigma. Low post-exposure vaccination rates are expected.

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.

Pathogen prioritisation for wastewater surveillance ahead of the Paris 2024 Olympic and Paralympic Games, France.

BackgroundWastewater surveillance is an effective approach to monitor population health, as exemplified by its role throughout the COVID-19 pandemic.AimThis study explores the possibility of extending wastewater surveillance to the Paris 2024 Olympic and Paralympic Games, focusing on identifying priority pathogen targets that are relevant and feasible to monitor in wastewater for these events.MethodsA list of 60 pathogens of interest for general public health surveillance for the Games was compiled. Each pathogen was evaluated against three inclusion criteria: (A) analytical feasibility; (B) relevance, i.e. with regards to the specificities of the event and the characteristics of the pathogen; and (C) added value to inform public health decision-making. Analytical feasibility was assessed through evidence from peer-reviewed publications demonstrating the detectability of pathogens in sewage, refining the initial list to 25 pathogens. Criteria B and C were evaluated via expert opinion using the Delphi method. The panel consisting of some 30 experts proposed five additional pathogens meeting criterion A, totalling 30 pathogens assessed throughout the three-round iterative questionnaire. Pathogens failing to reach 70% group consensus threshold underwent further deliberation by a subgroup of experts.ResultsSix priority targets suitable for wastewater surveillance during the Games were successfully identified: poliovirus, influenza A virus, influenza B virus, mpox virus, SARS-CoV-2 and measles virus.ConclusionThis study introduced a model framework for identifying context-specific wastewater surveillance targets for a mass gathering. Successful implementation of a wastewater surveillance plan for Paris 2024 could incentivise similar monitoring efforts for other mass gatherings globally.