Between the 25th and the 31st of January 2023 an eruption occurred several kilometres East of Epi Island, Vanuatu, an area known to host a submarine volcanic zone including several cones. The largest cone (Epi B) entered regularly in activity in the last century, and images of daily monitoring satellites confirmed its responsibility for the January 2023 eruption. The eruption evolved to Surtseyan on the 31st, producing ash and gas columns reaching more than 100 m above sea level and small pyroclastic surge moving across the water, with subsequent pumice rafts and water discolouration. The eruptive activity is visible on satellite imagery and was well recorded on seismic, hydroacoustic and infrasound stations that are part of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) International Monitoring System (IMS). Although this had no apparent consequences on the nearby communities, a small tsunami was however reported by locals and recorded on the coastal tide gauges of Port Vila 125 km to the south and Luganville 175 km to the north showing maximum amplitude of 5 cm. This data is used to validate the location and timing of the eruption and tentatively propose a tsunami mechanism. As a large part of the Vanuatu population is living in coastal areas, understanding tsunami mechanisms and assessing tsunami hazards associated with submarine eruptions is of main concern. Ultimately, this study aims to bring scientists and risk managers’ attention to a potentially hazardous volcano, through satellite and seismo-acoustic data analysis, numerical simulations of tsunami, and GIS mapping. • Submarine eruption in Vanuatu triggered a tsunami in January 2023 • Space-time origin is determined using satellite images and seismo-acoustic and sea-level data • Tsunami modelling via column collapse mechanism better matches gauge records
INTRODUCTION:Mother-to-child transmission (MTCT) of HIV, syphilis, and hepatitis B virus (HBV) commonly observed in the WHO African region is associated with excess morbidity and mortality. Despite some progress, the coverage of interventions to prevent MTCT of these infections remains insufficient, particularly for syphilis and HBV. To fulfil these gaps and achieve the triple elimination of MTCT of these infections by 2030, the World Health Organization (WHO) advocates for integration of prevention of MTCT (PMTCT) activities for HBV with HIV and syphilis antenatal services. In partnership with the local governments, the TRI-MOM project, conducted in 2 phases, aims to evaluate a simplified (based on inexpensive rapid diagnostic tests), integrated (in maternal and child health services) and coordinated (between the various programs and health care workers) strategy for the triple elimination of HIV, syphilis and HBV MTCT in Burkina Faso and The Gambia. METHODS AND ANALYSIS:The strategy will be implemented in 5 rural and urban health facilities in each country and will include four activities: i) training sessions for healthcare workers working in maternal and child health services, ii) screening of pregnant women of the three infections using rapid diagnostic tests at the first antenatal visit, iii) clinical assessment and treatment of women tested positive for any of the 3 infections, and iv) raising awareness on HIV, Syphilis and HBV PMTCT among pregnant women and empowering those screened positive. 17,000 pregnant women are expected to be screened. The strategy will be evaluated through an interdisciplinary, mixed-methods approach comprising three studies: i) a quantitative and qualitative cross-sectional study conducted both before and after the implementation of the strategy to assess its impact on triple screening coverage in pregnant women; ii) a an intervention study with longitudinal follow-up of pregnant women positive for any of the three infections to assess the coverage of PMTCT measures; and iii) a cost and cost-effectiveness analysis of the project compared to the reference situation in each country, which will rely on a micro costing study to estimate the incremental cost of the strategy per mother/child couple compared with the reference situation in each country, and compare it to the number of avoided infections. ETHICS AND DISSEMINATION:The study protocol has been approved by the competent authorities of the countries participating to the research (the LSHTM/MRCUG Scientific Coordinating Committee, the Gambia Government/MRC Joint Ethics Committee, the LSHTM ethics committee, the Burkinabe National Ethical Committee for Research in Health and the French Commission on Information Technology and Liberties). Results on the feasibility and acceptability of the triple elimination strategy will be disseminated using different media including policy briefs, posters and articles. TRIAL REGISTRATION NUMBER:ClinicalTrials.gov NCT05951751.
Background: HIV incidence in sub-Saharan Africa has declined substantially since 2000 according to epidemic estimates published by UNAIDS. These estimates, derived by fitting mathematical models to national surveillance data, guide HIV programmes and epidemic response strategies. We assessed whether the level and age distribution of HIV incidence from modelled estimates were consistent with empirical HIV incidence observations, and whether incidence levels and trends were systematically different between study types, populations, and age groups. Methods: We conducted an updated systematic review of adult HIV incidence data from sub-Saharan Africa published July 2019-February 2024 by searching Scopus, PubMed, Embase, and OVID databases, and combined with earlier systematic review data. We matched empirical incidence measurements between 1990-2023 to UNAIDS HIV incidence estimates by study area, sex, age group, and year. We used Bayesian mixed-effect Poisson regression to estimate (1) incidence rate ratios (IRR) between empirical observations and matched modelled incidence estimates adjusted for sex, year and study type/population; and (2) time trends in age-specific incidence from population-based cohort studies and household surveys. Results: 3560 HIV empirical incidence measurements were included from 179 studies conducted in 21 countries, comprising 23,000 new infections and 3.1 million person-years. Incidence observations from nationally-representative household surveys (IRR 1.07 95%CI 0.68, 1.67) and population-representative study populations (IRR 0.98 95%CI 0.51, 1.89) were not significantly different from matched modelled estimates, and declined at the same rate as modelled estimates (annual aRR 0.99 95%CI 0.98, 1.01). Studies among pregnant women (IRR 2.60 95%CI 1.58, 4.28), control arms of clinical trials (IRR 3.01 95%CI 1.90, 4.77) and key populations (FSW IRR: 6.46 95%CI 4.18, 10.00; MSM 44.02 95%CI 27.35, 70.87) had significantly higher incidence than modelled total population incidence estimates. Across population cohorts in Eastern and Southern Africa, HIV incidence among adults aged 15-49 declined by 75-90% between 2010-2023, and declined 7% (95%CI 4-10%) faster per year among young adults 15-24 compared to age 25+ years. Modelled incidence declined similarly to cohort data, but did not reflect the aging of the epidemic. Conclusion: Observed incidence in population-representative studies in sub-Saharan Africa has declined steeply. Mathematical models that infer incidence from cross-sectional HIV surveillance data estimated the same incidence level and decline over time as population-representative studies. Studies with non-representative inclusion criteria had significantly higher incidence, including those among pregnant women and most HIV prevention/vaccine efficacy trials. The age pattern of incidence in modelled estimates should be reconsidered to capture the aging of the epidemic indicated by cohort studies. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This research was funded by UNAIDS. OS and JWI-E acknowledge funding support from the Bill and Melinda Gates Foundation (INV-005576), and the MRC Centre for Global Infectious Disease Analysis (reference MR/R015600/1), jointly funded by the UK Medical Research Council (MRC) and the UK Foreign, Commonwealth & Development Office (FCDO), under the MRC/FCDO Concordat agreement and is also part of the EDCTP2 programme supported by the European Union. The study sponsor(s) had no role in study design; in the collection, analysis, and interpretation of data; in the writing of the report; or in the decision to submit the paper for publication. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Research Ethics Committee of Imperial College London gave ethical approval for this work (Reference number: 7045035) I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Analytical datasets are available at https://zenodo.org/records/18482588.
L’équipe Hydrogéologie en société se donne pour objectif de construire un dialogue équilibré entre scientifiques et habitants à propos des eaux souterraines en Mauritanie. Dans les oasis de l’Adrar, cela se traduit par un dispositif de recherche sur la salinisation des eaux, impliquant les oasiens. Après une année de travail sur le terrain, une journée de dialogue a été organisée avec ces derniers, pour favoriser l’échange de connaissances. Nous rendons compte de trois moments parlants de cette journée : une scène de théâtre réalisée avec les oasiens pour expliciter l’histoire du dispositif scientifique ; la présentation de l’état d’avancement du suivi des nappes par les oasiens et un exercice de cartographie des liens entre histoire, géologie et salinité. Ce travail donne à voir l’intensité des échanges de savoirs qui peuvent se nouer entre habitants et scientifiques, mais aussi l’exigence que cela implique en termes d’engagement des différents participants dans l’interaction.
Attempts to establish collaborative groundwater governance (CGG) have so far generally produced limited results in low- and middle-income countries. These shortcomings have been attributed to the high transaction costs associated with such approaches, making them impractical in informal water economies. This paper examines the obstacles to designing and implementing such an approach, through the analysis of a multistakeholder process conducted in a groundwater-depleted area in Northern Morocco. The process brought together farmers, staff members of public organisations, and other stakeholders to explore options for CGG. During the process, farmers created groundwater users associations and together the participants drafted an aquifer contract. The participatory process helped overcome several obstacles to CGG, particularly those related to farmers’ engagement. The finalisation of the aquifer contract was put on hold, however, due to the limited follow-up by state actors, the insufficient coordination among the numerous public actors involved, and weak political support. The study shows that CGG may not be inherently unfit for purpose in at least some low- and middle-income countries. Moreover, the participatory design of CGG can be an opportunity for horizontal dialogue between farmers operating in informal water economies and state administrations.
