Metropolitan France Research Articles

Lead-time-dependent calibration of a flood forecasting model

The hydrological models used for flood forecasting purposes are usually first calibrated in simulation mode and then applied for flood forecasting in combination with some data assimilation procedure allowing to update and correct the model in real-time. Such a two-step procedure may not be the best choice to train model parameters for forecasting purposes. An alternative approach is to calibrate the hydrological model separately for each target lead time in the presence of the updating procedure. However, it is unclear whether this approach can provide the most efficient and the most robust forecasts. We compared in this paper three approaches to calibrate the parameters of a flood forecasting model: calibration in simulation mode (i.e. without data assimilation), lead-time-dependent calibration (i.e. with data assimilation), and a procedure combining both approaches. An hourly flood forecasting model (a parsimonious hydrological model combined with a state updating assimilation procedure) was used to produce forecasts for three lead times on 687 catchments and 40,411 flood events in metropolitan France. The performance of the model calibrated with the three approaches was evaluated according to catchment response times and flood rise times. An analysis of parameter robustness was also carried out. The results showed that lead-time-dependent calibration improves performance for catchments characterised by slow temporal dynamics. However, for catchments with fast temporal dynamics, it leads to degraded performance at short lead times and reduces parameter robustness. We found that the combined calibration approach is the best compromise between parameter robustness and performance at all lead times and for all catchment and flood types.

Factors associated with mosquito-borne disease protective behaviour in metropolitan France

Abstract Background Mosquito-borne diseases (MBD) are increasing and expanding their range throughout metropolitan France. Promoting individual protective behaviour is imperative, but research on its determinants is limited to southern regions. This study examines factors influencing MBD protective behaviour in the metropolitan French population. Methods 2,087 subjects responded to a self-administered online questionnaire in November 2023. The analysis plan was pre-registered. We fitted two mixed effects models to estimate the frequency and count of protective behaviours across sociodemographic groups and to identify which factors predict protective behaviour. Results Frequency of protective behaviour is significantly positively associated with getting bitten by mosquitoes often (β = 3.39; 95% CI: 3.10, 3.69) and sometimes (β = 1.54; 95% CI: 1.31, 1.76) compared to almost never, perceived MBD threat (β = 0.11; 95% CI: 0.06, 0.15), and having financial difficulties (β = 0.23; 95% CI: 0.02, 0.43). Count of protective behaviours is associated with getting bitten by mosquitoes often (β = 0.39; 95% CI: 0.30, 0.49) and sometimes (β = 0.14; 95% CI: 0.05, 0.23), perceived MBD threat (β = 0.02; 95% CI: 0.00, 0.03), MBD knowledge (β = 0.06; 95% CI: 0.04, 0.08), and having a chronic disease (β = 0.08; 95% CI: 0.02, 0.14). Models were adjusted for place of residence, education, and age. No associations were found between sex, having experienced an MBD, or confidence in public authorities to manage health crises. Conclusions This study provides the first insights into MBD protective behaviour and its associated factors considering all metropolitan French regions. Our results highlight several factors which may inform MBD prevention communication and policies focused on increasing individual protective behaviour. Key messages • People often bitten by mosquitoes are more likely to engage in more frequent and a higher number of mosquito-borne disease protective behaviour than people almost never bitten by mosquitoes. • Higher perceived mosquito-borne diseases threat is associated with more frequent and a higher number of mosquito-borne disease protective behaviour.

Occupational class difference in COVID-19 symptoms in France: contribution of work-related exposures

Abstract Background The association between socio-occupational class and SARS-CoV-2 infection remains inconclusive and may depend on the setting and the pandemic stage. Our study aims to quantify self-reported COVID-19 symptoms by occupational class (OC) in spring 2020 in France and explain observed differences using work-related risk factors. Methods We analyzed data from the EpiCoV population-based cohort, comprising 46,849 active workers aged 18-64 in metropolitan France. COVID-19 symptoms were sudden loss of taste/smell, fever with cough, fever with shortness of breath, or fever with chest oppression. Separating regions highly affected by COVID-19 from other regions, we related OC with reporting of COVID-19 symptoms and assessed the mediation effect of work-related SARS-CoV-2 exposures (contact with the public, using public transportation, self-perceived exposure) using the Karlson-Holm-Breen mediation analysis method. Results During the study period, 7.1% of the workers reported COVID-19 symptoms. In both regions, work-related SARS-CoV-2 exposures were related to higher reporting of symptoms, and those exposures were more prevalent in the lowest than in the highest OCs. However, the association of OC with reporting symptoms was not the same in the two regions. In less affected regions, the lowest OC reported COVID-19 symptoms less often than the highest OC, whereas in highly affected regions, symptoms were more frequent in middle OCs, and this was partly explained by work-related SARS-CoV-2 exposures. Conclusions Different socio-occupational patterns of symptoms were observed in the two groups of regions. The situation in the less affected regions, with more reporting in the highest relative to the lowest classes, may be attributable to exposure factors playing a role opposite to that of work-related exposures. Further studies on OC disparities in COVID-19 severity are needed based on hospitalization and mortality. Key messages • During the early pandemic, in regions less affected by COVID-19, the upper occupational class reported more COVID-19 symptoms, whereas the middle class did so in highly affected regions. • Work-related exposure to SARS-CoV-2 mediates the association between occupational class and reporting COVID-19 symptoms to some extent, even when the occupational gradient is reversed.

GIS and statistics to analyze scale change consequences on medical desert classification in France

Abstract Background Accessibility is a crucial way to overcome geographical restrictions and provides a path for alleviating the medical desert. Less attention has been paid to the choice of spatial unit in the effect of healthcare multi-accessibility. Inside the OASES European program, the France team proposes to create medical desert classification at the municipality level. The contribution of this study is to highlight the consequences of the choice of spatial scale on spatial distribution and the discrepancies between medical desert classifications. Methods Analyses were carried out in metropolitan France and overseas departments, at the commune scale and two other supra-communal scales used by public policies in France. For each spatial unit, a multidimensional and professional classification has been conducted using a three-step method: scores, principal component analysis and clustering. To demonstrate the presence of spatial dependence and to measure homogeneity between classifications joint count autocorrelation indicators and Theil’s indexes were applied. Results Our results present 7 classes of municipalities, and 5 classes of EPCI or living territories according to their level of healthcare accessibility, the dynamic of supply, and the needs of the population. Spatial representation of the classification demonstrates greater variability at the municipality level than other supra scales. Informative contrasted classes at the municipality level disappeared in favor of the middle class in all accessibility at supra scales. The results demonstrate that spatial dependence between areas at the municipality level reduced the scale effect. Conclusions Spatial approaches have become increasingly popular since they enable decision-makers to identify priority areas and allocate resources. Recognizing the instability across various scales is therefore crucial for thinking about the optimal unit of data aggregation when investigating the medical desert. Key messages • Choice of the scale is a mix between public policy decisions and data availability. • Contiguity constraint is a way to reduce the loss of information after aggregation.

Territorial health inequalities in breast cancer mortality across France from 1968 to 2017

Abstract Background Territorial health inequalities are of growing concern in countries with universal health systems. From 2003, three successive national cancer plans were launched in France, aiming to improve prevention and treatment. Regions in France are responsible for strategic and financial management of healthcare within their boundaries, which, until 2016, included up to 8 departments. In this study, we analyze the evolution of between and within-region territorial inequalities in breast cancer mortality over 50 years. Methods We used direct and indirect standardization to analyze trends in breast cancer mortality for women aged 25 to 74 years between 1968 and 2017 in each department of metropolitan France. We analyzed the evolution of relative inequalities over time using standard errors of age-adjusted rates. We used multilevel Poisson regression to estimate how much the regional level contributed to territorial variation. Results Over the period 1968 to 1992, breast cancer standardized mortality ratios (SMRs) increased (+16%) while relative territorial inequalities decreased (-21%). After 1997, SMRs decreased (-23%) but territorial inequalities remained unchanged. In 18 out of 22 regions, inequalities were lower at the end than at the start of the study period. Period proved to be the most important determinant of variation in mortality. However, multilevel models also suggested that the regional level explained most of the remaining variation in each period (from 50% to over 80%). Conclusions Over the study period in most French regions, breast cancer mortality has decreased, and so have relative inequalities. Nevertheless, there is evidence that regions have performed differently. The proportion of variation explained by the regional level suggests the continued relevance of the health system on breast cancer mortality. Key messages • Territorial inequality in breast cancer mortality has decreased in France over the 1968-2017 period. • In most regions, disparities between departments have decreased.

Clinical profiles of older adults in French Caribbean nursing homes: a descriptive cross-sectional study.

Nursing homes in the Caribbean are scarce and the characteristics of their residents have not been previously documented. This study aimed to describe the clinical profiles of residents living in nursing homes in Guadeloupe and Martinique (French West Indies). This is a cross-sectional study of the baseline screening data from the KASEHPAD (Karukera Study of Ageing in nursing homes) study. Clinical characteristics and geriatric scale scores, including the Activities of Daily Living (ADL), Mini-Mental State Examination (MMSE), Mini Nutritional Assessment Short-Form (MNA-SF) and Short Physical Performance Battery (SPPB) were collected and analysed. A total of 332 older adults were recruited between September 2020 and November 2022. The mean age of the residents was 81.3 ± 10.1, with a male-female ratio of 1:1. Diabetes was reported in 28.3% of the residents, hypertension in 66.6% and heart disease in 18.4%. Dementia was diagnosed in 52.3% of the residents and 74.9% had a MMSE score ≤18. The prevalence of Parkinson's disease was 9.0%. Additionally, 18.4% were unable to perform any basic activities of daily living (ADL score of 0). The prevalence of physical impairment (SPPB < 8) was 90.0%. One-quarter of the residents were classified as undernourished (MNA-SF score ≤ 7). Residents in Caribbean nursing homes are younger than in metropolitan France, whereas they present quite similar clinical profiles. Notably, a high prevalence of diabetes, cardiovascular diseases and neurodegenerative diseases was observed. This study represents a preliminary effort to address the knowledge gap regarding the aging trajectories of older adults in the Caribbean and could guide the development of future nursing homes in these countries.

Giving a voice to “the silent killer”: a knowledge, attitude and practice study of diabetes among French Guiana’s Parikweneh people

BackgroundThe prevalence of type 2 diabetes (T2D) in the French overseas department of French Guiana, South America, nearly doubles that in its European counterpart, Metropolitan France. This region is demographically diverse and includes several populations of Indigenous Peoples. Although such populations are at particular risk of developing T2D across the Americas, very little is known about their health status in French Guiana, and accurate numbers of diabetic patients do not exist.MethodsIn light of a potential public health crisis, an ethnomedicinal study of diabetes experienced by Indigenous Parikweneh was conducted to provide better insight into the knowledge, attitudes and practices (KAP) related to this quickly emerging disease in French Guiana. Altogether, 75 interviews were conducted with community members and Elders, as well as healthcare professionals and administrators providing services to the Parikweneh population of Macouria and Saint-Georges de l’Oyapock.ResultsInterviews suggest a high incidence of T2D in this population, with cases that have risen quickly since the mid-twentieth century. Parikweneh participants linked the development of the illness to dietary changes, notably through the introduction of new and sweet foods. Recognizing the complexity of diabetes and its symptoms, diabetic patients highlighted the importance of biomedical treatments and follow-ups, though they frequently alternated or used them concomitantly with Parikweneh medicines. With the help of biomedical tools (i.e. glucometer), local medicinal practices mirrored biomedical approaches through dietary adaptation and the use of medicinal animals and plants for glycaemic control and the treatment of complications from the disease.ConclusionParikweneh are appropriating T2D into their knowledge system and adapting their health system in response to this relatively new health concern. A greater understanding of local practices and perceptions relating to T2D among medical staff may therefore be beneficial for meeting patients’ needs, providing greater autonomy in their health path, and improving treatment outcomes.

Early childcare and developmental delay risk at 3.5 years: Insights from the French ELFE cohort.

We tested the association between early childcare attendance in the first three years of life and child development at age 3.5years in the French context, where early childcare is subsidized. In the ELFE (Étude Longitudinale Français depuis l'Enfance) birth cohort study set in metropolitan France, children's development was reported by parents at age 3.5years (n = 11,033) via the Child Development Inventory (CDI) questionnaire. CDI scores were transformed into a development quotient (DQ), with a DQ < 90 corresponding to possible and a DQ < 85 corresponding to a probable developmental delay. Inverse probability weighted multivariable regression models were used to analyse whether early childcare in the first three years of life (centre-based, childminder, informal or parental care) was associated to development delay. Compared to children in exclusive parental care, those in centre-based childcare (CBC) or with a childminder prior to school entry were significantly less likely to experience possible (OR = 0.56, [95% CI = 0.51-0.61] for CBC and OR = 0.77, [95% CI = 0.72-0.83] for childminder attendance) and probable developmental delay (OR = 0.62, [0.58-0.67] for CBC and OR = 0.80 [0.76-0.83] for childminder). Informal childcare attendance was not significantly associated with children's possible nor probable developmental delay ((OR = 0.97, [0.84-1.12]) and (OR = 0.97, [0.82-1.15]), respectively). Conclusions: Overall, our findings add to the existing scientific literature, showing that in the French context, where childcare can start as early as 3months of age, early childcare attendance can contribute to child's development. What's Known on This Subject: • Studies on early childcare attendance and child development have shown mixed results, associations with better psychomotor development mainly being observed in Nordic countries, while some studies in other countries such as the USA showed no or negative associations. What This Study Adds: • In a country with broad and subsidized access to childcare such as France, access to early childhood education can positively contribute to children's psychomotor development. However, we found that access to childcare does not appear to reduce social inequalities in children's psychomotor development.

Association Between COVID-19 and Self-Harm: Nationwide Retrospective Ecological Spatiotemporal Study in Metropolitan France.

The COVID-19 pandemic has not been associated with increases in suicidal behavior at the national, regional, or county level. However, previous studies were not conducted on a finer scale or adjusted for ecological factors. Our objective was to assess the fine-scale spatiotemporal association between self-harm and COVID-19 hospitalizations, while considering ecological factors. Using the French national hospital discharge database, we extracted data on hospitalizations for self-harm of patients older than 10 years (from 2019 to 2021) or for COVID-19 (from 2020 to 2021) in metropolitan France. We first calculated monthly standardized incidence ratios (SIRs) for COVID-19 between March 2020 and December 2021, using a Besag, York, and Mollié spatiotemporal model. Next, we entered the SIRs into an ecological regression in order to test the association between hospital admissions for self-harm and those for COVID-19. Lastly, we adjusted for ecological variables with time lags of 0 to 6 months. Compared with a smoothed SIR of ≤1, smoothed SIRs from 1 to 3, from 3 to 4, and greater than 4 for COVID-19 hospital admissions were associated with a subsequent increase in hospital admissions for self-harm, with a time lag of 2 to 4 months, 4 months, and 6 months, respectively. A high SIR for hospital admissions for COVID-19 was a risk factor for hospital admission for self-harm some months after the epidemic peaks. This finding emphasizes the importance of monitoring and seeking to prevent suicide attempts outside the epidemic peak periods.

New guidelines reduce the risk of hospitalization for adult patients with uncomplicated Plasmodium falciparum malaria: An observational, multicenter, retrospective French study

ObjectivesWe aimed to evaluate the impact of malaria declaration year (before or after 2017) on the frequency of hospitalization in metropolitan France of patients with uncomplicated non-vomiting P.falciparum malaria. Patients and methodsAn observational, multicenter, retrospective study was carried out, using the database from the French National Reference Centre for Malaria. Descriptive analysis and multivariate analysis by logistic regression were performed using the multiple imputation by chained equation method to handle missing data. ResultsMore than 2000 (2184) uncomplicated non-vomiting P.falciparum malaria cases were recorded. Our multivariate analysis showed an association between the year 2018 and reduced risk of hospitalization (OR: 0.89; 95% CI: 0.81–0.97). ConclusionCompared to 2016, during 2018 we observed a trend toward ambulatory care for patients presenting with uncomplicated non-vomiting P.falciparum malaria.

Meteorological factors and rhegmatogenous retinal detachment in metropolitan France

Rhegmatogenous retinal detachment (RRD) is a sight-threatening condition with rising global incidence. Identifying factors contributing to seasonal variations in RRD would allow a better understanding of RRD pathophysiology. We therefore performed a retrospective case series study investigating the relationship between RRD occurrence and meteorological factors throughout metropolitan France (the METEO-POC study), particularly the mean temperature over the preceding 10-day period (T-1). Adult patients having undergone RRD surgery and residing in one of the three most populated urban areas of each French region were included (January 2011–December 2018). The study involved 21,166 patients with idiopathic RRD (61.1% males, mean age 59.8–65.1 years). RRD incidence per 100,000 inhabitants increased from 7.79 to 11.81. RRD occurrence was not significantly associated with mean temperature over T-1 in the majority of urban areas (31/36). In a minority of areas (5/36) we observed correlations between RRD incidence and mean temperature over T-1, however these were extremely weak (r = 0.1–0.2; p < 0.05). No associations were found between RRD incidence and secondary outcomes: mean daily temperature over the 10 days prior T-1, minimum/maximum temperatures, rainfall, duration of sunshine, atmospheric pressure, overall radiation, relative humidity, wind speed. Overall, we found no relationships between meteorological parameters and RRD occurrence.

Implementation of a Novel Epidemiological Surveillance System for Children's Mental Health and Well-Being in France: Protocol for the National "Enabee" Cross-Sectional Study.

Children's mental health, including their well-being, is a major public health concern, as the burden of related disorders may last throughout one's life. Although epidemiological mental health surveillance systems for children and adolescents have been implemented in several countries, they are sorely lacking in France. This study aims to describe the first step of the implementation of a novel surveillance system in France called Enabee (Etude nationale sur le bien-être des enfants), which focuses on the issue of mental health in children. The system aims to (1) describe the temporal trends in the population-based prevalence of the main mental health disorders and well-being in children aged 3 to 11 years, (2) explore their major determinants, and (3) assess mental health care use by this population. To do this, Enabee will rely on results from a recurrent national cross-sectional homonymous study. This paper presents the protocol for the first edition of this study (called Enabee 2022), as well as initial results regarding participation. Enabee 2022 is a national cross-sectional study that was implemented in French schools in 2022. It used a probabilistic, multistage, stratified, and balanced sampling plan as follows: first, schools were randomly drawn and stratified according to the type of school. Up to 4 classes per school were then randomly drawn, and finally, all the pupils within each class were selected. The study covered children from preschool and kindergarten (aged 3 to 6 years, US grading system) to fifth grade (aged 6 to 11 years). Children from first to fifth grades provided a self-assessment of their mental health using 2 validated self-administered questionnaires: the Dominic Interactive (DI) and the KINDL. Parents and teachers completed a web-based questionnaire, including the Strengths and Difficulties Questionnaire. Parents also answered additional questions about their parenting attitudes; their own mental health; known social, economic, and environmental determinants of mental health in children; and their child's life habits. Health, education, and family stakeholders were involved in designing and implementing the study as part of a large consultation group. Data were collected from May 2, 2022, to July 31, 2022, in 399 schools across metropolitan France. Teachers completed questionnaires for 5721 pupils in preschool and kindergarten and for 15,263 pupils from first to fifth grades. Parents completed questionnaires for 3785 children in preschool and kindergarten and for 9227 children from first to fifth grades. Finally, 15,206 children from first to fifth grades completed the self-administered questionnaire. Enabee 2022 constitutes the first milestone in the development of a novel national epidemiological surveillance system, paving the way for improved children's mental health policies in France.

Consent for interventions during childbirth: A national population-based study.

To assess the frequency and determinants of medical interventions during childbirth without women's consent at the population level. The nationwide cross-sectional Enquête Nationale Périnatale 2021 provided a representative sample of women who delivered in metropolitan France with a 2-month postpartum follow-up (n = 7394). Rates and 95% confidence intervals (CI) of interventions during childbirth (oxytocin administration, episiotomy or emergency cesarean section) without consent were calculated. Associations with maternal, obstetric, and organizational characteristics were assessed using robust variance Poisson regressions, after multiple imputation for missing covariates, and weighted to account for 2-month attrition. Women reporting failure to seek consent were 44.7% (CI: 42.6-47.0) for oxytocin administration, 60.2% (CI: 55.4-65.0) for episiotomy, and 36.6% (CI: 33.3-40.0) for emergency cesarean birth. Lack of consent for oxytocin was associated with maternal birth abroad (adjusted prevalence ratio [aPR] 1.20; 95% CI: 1.06-1.36), low education level, and increased cervical dilation at oxytocin initiation, whereas women with a birth plan reported less frequently lack of consent (aPR 0.79; 95% CI: 0.68-0.92). Delivery assisted by an obstetrician was more often associated with lack of consent for episiotomy (aPR 1.46; 95% CI: 1.11-1.94 for spontaneous delivery and aPR 1.39; 95% CI: 1.13-1.72 for instrumental delivery, reference: spontaneous delivery with a midwife). Cesarean for fetal distress was associated with failure to ask for consent for emergency cesarean delivery (aPR 1.58; 95% CI: 1.28-1.96). Women frequently reported that perinatal professionals failed to seek consent for interventions during childbirth. Reorganization of care, particularly in emergency contexts, training focusing on adequate communication and promotion of birth plans are necessary to improve women's involvement in decision making during childbirth.

Challenges of molecular barcode-based identification of earthworm specimens for biodiversity assessment

Specimen identification at the species level is a critical challenge for understanding community structure and conserving biodiversity. The use of mitochondrial DNA barcodes, in addition to morphology, has proven to be a useful tool for earthworm identification, but it has also raised difficulties. Thus, approaches to delineating molecular operational taxonomic units (MOTUs) from cytochrome c oxidase subunit 1 (COI) or 16S rDNA sequence data often reveal more mitochondrial lineages than morphospecies, raising the question of whether these MOTUs should be used as taxonomic entities in community structure studies. Here, we used a newly acquired dataset of 576 COI barcodes of earthworms from Metropolitan France that were clustered in 36 MOTUS, corresponding to 21 morphospecies. We also incorporated data gathered from the literature to investigate this question. In order to match our MOTUs with already-described mitochondrial lineages, we downloaded reference sequences from the GenBank and BOLD platforms. In light of the difficulties encountered in recovering these sequences, we recommend that any new mitochondrial lineage described in a study be named consistently with previous works. Next, we analyzed the biological, ecological, and molecular data available in the literature on the different mitochondrial lineages that matched our MOTUs in order to determine if there was a consensus for species delimitation. Although the study specimens mainly belong to the Lumbricidae, which is one of the most studied families of earthworms, the data are often missing to determine if the MOTUs correspond to different species. Pending revision of the taxonomy, MOTUs for which mitochondrial divergence has been confirmed by morphological differences should be considered distinct taxonomic entities in community structure studies. In the absence of morphological differences and pending more data, we propose to distinguish for these analyses, within sexually reproducing morphospecies, the MOTUs for which mitochondrial divergence has been confirmed by multilocus nuclear data, while in the case of reproduction by parthenogenesis, ecological differences between MOTUs are necessary to consider them as different taxonomic entities.

Mercury exposure and trophic ecology of urban nesting black-legged kittiwakes from France

Seabirds are increasingly used as bioindicators for assessing the chemical contamination of marine ecosystems, including by mercury (Hg) worldwide. However, some geographical areas are still poorly documented, as metropolitan France that is home to 28 seabird species including the black-legged kittiwake Rissa tridactyla, in the part of the southern limit of the North Atlantic range of the species. Here, we investigated Hg contamination and trophic ecology of black-legged kittiwakes breeding in the harbour of Boulogne-sur-Mer, Northern France. Mean blood Hg concentration was 4.81 ± 1.20 μg g−1 dw (dry weight), 3.66 ± 0.75 μg g−1 dw and 0.43 ± 0.07 μg g−1 dw for adult males, adult females, and chicks, respectively. According to Hg toxicity benchmarks for avian blood, 30% of the sampled adults were considered to be at moderate risk to Hg toxicity. Stable isotope and food analyses showed that highest δ15N values (reflecting a higher trophic position) were related to highest blood Hg concentrations in adult birds, and that Atlantic herring (Clupea harengus) and Atlantic mackerel (Scomber scombrus) were the main prey. Adult kittiwakes from Boulogne-sur-Mer showed Hg levels three times higher than those found in Arctic nesting kittiwakes, where sublethal effects have been documented. This study provides a first description of Hg contamination of black-legged kittiwakes breeding in France and calls for future ecotoxicological research to assess the vulnerability of this species in the southern part of its distribution range.

Prevalence of the crayfish plague pathogen in red swamp crayfish populations in western France: How serious is the risk for the native white-clawed crayfish?

The crayfish plague pathogen Aphanomyces astaci has been implicated in a number of mass mortalities and irreversible population declines of native crayfish across Europe. At present, the reservoirs of the pathogen in Europe are mainly populations of invasive North American crayfish species. In southwestern Europe, including France, a particularly widespread invader is the red swamp crayfish Procambarus clarkii. Recent distribution data confirm that P. clarkii is present in at least 75 French departments, i.e. more than 78% of those in metropolitan France. We analysed the prevalence and pathogen load of A. astaci in 42 populations of this species in western France (Nouvelle Aquitaine region), where the species is most densely distributed, particularly in a wide range of environments around the Gironde estuary. The pathogen was detected by two different quantitative PCR assays in more than three quarters of the populations studied (34 out of 42); 163 out of 480 analysed crayfish individuals tested positive for the presence of A. astaci. In most cases, individual infection levels were very low, detectable with quantitative PCR but not sufficient for pathogen genotyping. In seven P. clarkii individuals from four populations, however, we were able to assess A. astaci variation by microsatellite markers and sequencing of mitochondrial markers. All these host specimens carried A. astaci genotype group D, haplotype d1, which has caused the majority of crayfish plague outbreaks in neighbouring Spain. In contrast, the French outbreaks genotyped to date (including eight newly analysed in this study) were mostly caused by strains of genotype group B, specific to the signal crayfish Pacifastacus leniusculus. Haplotype d1 found in P. clarkii was involved in one of the newly characterised outbreaks. Our study confirms that P. clarkii is a potentially important reservoir of the crayfish plague pathogen in France, but not the main source of the pathogen in mass mortalities of A. pallipes, probably due to different ecological requirements of the different invasive host crayfish. However, as P. clarkii continues to spread, the threat posed by this species to native crayfish is likely to increase.

Seroprevalence of human herpes viruses in France, 2018–2022: a multilevel regression and poststratification approach

Background Information related to herpes simplex virus 1 and 2 (HSV-1 and 2), varicella-zoster virus (VZV), Epstein-Barr virus (EBV), and cytomegalovirus (CMV) seroprevalence in France is either lacking, incomplete, or outdated, despite their public health burden. Method We used routinely collected serological data between 2018 and 2022 to estimate HSV-1, HSV-2, VZV, EBV, and CMV seroprevalence in France. To account for demographic differences between our analytic samples and the French population and get estimates for sparsely sampled districts and age classes, we used a multilevel regression and poststratification approach combined with Bayesian model averaging via stacking weights. Results The observed seroprevalence (number of positive tests/number of tests) were 64.6% (93,294/144,424), 16.9% (24,316/144,159), 93.0% (141,419/152,084), 83.4% (63,199/75, 781), and 49.0% (23,276/47,525), respectively, for HSV-1, HSV-2, VZV, EBV, and CMV. Between 2018 and 2022, France had a model-based average (equal-tailed interval at 95%) expected seroprevalence equal to 61.1% (60.7,61.5), 14.5% (14.2,14.81), 89.5% (89.3,89.8), 85.6% (85.2,86.0), and 50.5% (49.3,51.7), respectively, for HSV-1, HSV-2, VZV, EBV, and CMV infections. We found an almost certain lower expected seroprevalence in Metropolitan France than in overseas territories for all viruses but VZV, for which it was almost certainly greater. The expected seroprevalences were likely greater among females for all viruses. Limitations Our results relied on the assumption that individuals were sampled at random conditionally to variables used to build the poststratification table. Implications The analysis highlights spatial and demographic patterns in seroprevalence that should be considered for designing tailored public health policies.

Using supervised machine learning for regional hydrological hazard estimation in metropolitan France

Study regionThis study is carried out for 1929 gauged catchments in France, ranging from 1 to 10,000 km², where quality hydrometric observations are available for flood frequency analysis. Study focusThe regional estimation of hydrological hazards is studied for flood risk management and prevention in hydrology. For gauged catchments, flow quantiles can be estimated from observations using statistical approaches based on suitable probability distributions or simulation approaches based on rainfall-runoff transformation models. For ungauged catchments, the lack of hydrological observations means that we have to extrapolate our knowledge of hazards from gauged catchments to ungauged catchments, using regionalization methods. It is therefore necessary to combine regionalization methods with the implemented hazard estimation approach. In this paper, two popular machine learning methods, Random Forest and Neural Networks, are tested and compared as regionalization methods. A classical regionalization method using multiple linear regression is also applied as a benchmark to evaluate the performance of all configurations. All these regionalization methods are applied to a simulation-based approach (the SHYREG method) and to a statistical-based approach using generalized extreme value distribution (GEV). New hydrological insights•Regionalization approaches based on multiple linear regression have limitations to explain parameters with environmental descriptors in Regional Flood Frequency Analysis (RFFA) domain.•Regionalizing RFFA parameters using Random Forest allows more explanatory variables to be considered through non-linear relationships, resulting in better parameter estimation.•Machine learning techniques can better handle environmental descriptors for regionalization, this providing a notable performance improvement, especially for the statistical approach.•The tested simulation-based approach is less sensitive to the choice of spatial interpolation method than the studied statistical approach.

Métis In the Mainstream: The Ambivalent Blackness and Legacy of Henri Salvador

ABSTRACT Existing studies of musical blackness in France either focus on inter-war jazz or on post-1990 rap and “urban pop.” This article bridges the gap by studying the songs and career of Henri Salvador (1917-2008), a singer and guitarist of Guadeloupean origin who successfully transitioned, in metropolitan France, from the 1930s fashion for Creole music to mainstream pop in the 1950s and beyond. His success as a métis or mixed-race artist straddled racial stereotyping and abstract Frenchness, revealing complexities around race that problematize the relevance of blackness and métissage (French-style multiculturalism) for framing the work of Black pop musicians in France.

Antibiotic prescriptions associated with a diagnosis of acute nasopharyngitis by GPs in France: a retrospective study.

Nasopharyngitis is a common viral infection that has led to an overuse of prescription drugs, in particular antibiotics, which are not indicated for this condition. The purpose of this study was to describe drug prescriptions for patients with a diagnosis of acute rhinopharyngitis in general practices in France. Retrospective study of 1 067 403 prescriptions for a diagnosis of nasopharyngitis issued by 2637 physicians to 754 476 patients living in metropolitan France. The data were sourced from the prescription software, Cegedim, for the period 1 January 2018 to 31 December 2021 and analysed according to patients' and physicians' ages. A total of 2 591 584 medications were prescribed by GPs, with a median of three medications per patient. A total of 171 540 courses of antibiotics were prescribed (16% prescription rates), with amoxicillin being the most frequently prescribed (102 089 prescriptions; 59.5% of antibiotic prescriptions). Amoxicillin prescription increased in extreme age groups (18.2% of visits in those aged 9 years and under, and 10.0% of visits in those aged over 80 years, while patients aged 20-29-years were prescribed amoxicillin in just 2.9% of visits), and more prescriptions are issued by older doctors (GPs older than 70 years prescribed antibiotics in 26.4% of visits versus 3.2% of visits by GPs aged under 29 years). Nasopharyngitis is frequently a cause of therapeutic over-prescriptions including antibiotics, with an antibiotic prescription rate of 16%. Additional research is required to enhance our understanding of factors linked to drug prescriptions.