Education as Risk Factor of Mild Cognitive Impairment: The Link to the Gut Microbiome.

BACKGROUND: With differences apparent in the gut microbiome in mild cognitive impairment (MCI) and dementia, and risk factors of dementia linked to alterations of the gut microbiome, the question remains if gut microbiome characteristics may mediate associations of education with MCI. OBJECTIVES: We sought to examine potential mediation of the association of education and MCI by gut microbiome diversity or composition. DESIGN: Cross-sectional study. SETTING: Luxembourg, the Greater Region (surrounding areas in Belgium, France, Germany). PARTICIPANTS: Control participants of the Luxembourg Parkinson's Study. MEASUREMENTS: Gut microbiome composition, ascertained with 16S rRNA gene amplicon sequencing. Differential abundance, assessed across education groups (0-10, 11-16, 16+ years of education). Alpha diversity (Chao1, Shannon and inverse Simpson indices). Mediation analysis with effect decomposition was conducted with education as exposure, MCI as outcome and gut microbiome metrics as mediators. RESULTS: After exclusion of participants below 50, or with missing data, n=258 participants (n=58 MCI) were included (M [SD] Age=64.6 [8.3] years). Higher education (16+ years) was associated with MCI (Odds ratio natural direct effect=0.35 [95% CI 0.15-0.81]. Streptococcus and Lachnospiraceae-UCG-001 genera were more abundant in higher education. CONCLUSIONS: Education is associated with gut microbiome composition and MCI risk without clear evidence for mediation. However, our results suggest signatures of the gut microbiome that have been identified previously in AD and MCI to be reflected in lower education and suggest education as important covariate in microbiome studies.

Local retail food environment exposure and diet quality in rural and urban adults: A longitudinal analysis of the ORISCAV-LUX cohort study.

Despite growing interest in understanding how food environments shape dietary behaviors, European longitudinal evidence is scarce. We aimed to investigate the associations of 9-year average and change in exposure to local retail food environments with the diet quality of residents in Luxembourg. We used data from 566 adults enrolled in both waves of the nationwide ORISCAV-LUX study (2007-2017). Dietary quality was assessed by the Diet Quality Index-International (DQI-I). Exposure to "healthy" and "less healthy" food outlets was assessed by both absolute and relative GIS-based measurements. The results showed a 56.3% increase in less healthy food outlets over the period. In adjusted linear mixed models, high (vs. low) 9-year average exposure to less healthy food outlets was associated with lower DQI-I, when examining spatial access (ß = -1.25, 95% CI: -2.29, -0.22) and proportions (ß = -1.24, 95% CI: -2.15, -0.33). Stratified analyses showed these associations to be significant only among urban residents. There was no association between change in exposure to less healthy food outlets and DQI-I. Increased exposure to healthy outlets in rural areas, using absolute measurements, was associated with worsened DQI-I. Neighborhood socioeconomic status did not moderate the above associations. Findings suggest that the proliferation of less healthy food outlets may have contributed to the deterioration of the diet quality of urban residents, and support the use of relative measurements to fully capture the healthiness of food environments.

Creation of a pandemic memory by tracing COVID-19 infections and immunity in Luxembourg (CON-VINCE).

BACKGROUND: During the COVID-19 pandemic swift implementation of research cohorts was key. While many studies focused exclusively on infected individuals, population based cohorts are essential for the follow-up of SARS-CoV-2 impact on public health. Here we present the CON-VINCE cohort, estimate the point and period prevalence of the SARS-CoV-2 infection, reflect on the spread within the Luxembourgish population, examine immune responses to SARS-CoV-2 infection and vaccination, and ascertain the impact of the pandemic on population psychological wellbeing at a nationwide level. METHODS: A representative sample of the adult Luxembourgish population was enrolled. The cohort was followed-up for twelve months. SARS-CoV-2 RT-qPCR and serology were conducted at each sampling visit. The surveys included detailed epidemiological, clinical, socio-economic, and psychological data. RESULTS: One thousand eight hundred sixty-five individuals were followed over seven visits (April 2020-June 2021) with the final weighted period prevalence of SARS-CoV-2 infection of 15%. The participants had similar risks of being infected regardless of their gender, age, employment status and education level. Vaccination increased the chances of IgG-S positivity in infected individuals. Depression, anxiety, loneliness and stress levels increased at a point of study when there were strict containment measures, returning to baseline afterwards. CONCLUSION: The data collected in CON-VINCE study allowed obtaining insights into the infection spread in Luxembourg, immunity build-up and the impact of the pandemic on psychological wellbeing of the population. Moreover, the study holds great translational potential, as samples stored at the biobank, together with self-reported questionnaire information, can be exploited in further research. TRIAL REGISTRATION: Trial registration number: NCT04379297, 10 April 2020.

Impact of nirsevimab prophylaxis on paediatric respiratory syncytial virus (RSV)-related hospitalisations during the initial 2023/24 season in Luxembourg.

After Luxembourg introduced nirsevimab immunisation against respiratory syncytial virus (RSV), estimated neonatal coverage was 84% (1,277 doses/1,524 births) in 2023. That year, paediatric RSV-related hospitalisations, especially concerning infants < 6 months old (n = 72) seemed to decrease compared to the same period in 2022 (n = 232). In 2023, hospitalised children's mean age increased (14.4 months vs 7.8 months in 2022; p < 0.001) and hospital-stay length decreased (3.2 days vs 5.1 days; p < 0.001). In infants < 6 months old, intensive-care unit admissions appeared to drop (n = 28 vs 9). This suggests that nirsevimab prophylaxis reduced severe RSV infections, particularly in infants < 6 months old, thereby alleviating healthcare strain.

eDNA-based monitoring of Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans with ddPCR in Luxembourg ponds: taking signals below the Limit of Detection (LOD) into account.

BACKGROUND: Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal) are two pathogenic fungi that are a significant threat to amphibian communities worldwide. European populations are strongly impacted and the monitoring of the presence and spread of these pathogens is crucial for efficient decision-making in conservation management. RESULTS: Here we proposed an environmental DNA (eDNA) monitoring of these two pathogenic agents through droplet digital PCR (ddPCR) based on water samples from 24 ponds in Luxembourg. In addition, amphibians were swabbed in eight of the targeted ponds in order to compare the two approaches at site-level detection. This study allowed the development of a new method taking below-Limit of Detection (LOD) results into account thanks to the statistical comparison of the frequencies of false positives in no template controls (NTC) and below-LOD results in technical replicates. In the eDNA-based approach, the use of this method led to an increase in Bd and Bsal detection of 28 and 50% respectively. In swabbing, this resulted in 8% more positive results for Bd. In some samples, the use of technical replicates allowed to recover above-LOD signals and increase Bd detection by 35 and 33% respectively for eDNA and swabbing, and Bsal detection by 25% for eDNA. CONCLUSIONS: These results confirmed the usefulness of technical replicates to overcome high levels of stochasticity in very low concentration samples even for a highly sensitive technique such as ddPCR. In addition, it showed that below-LOD signals could be consistently recovered and the corresponding amplification events assigned either to positive or negative detection via the method developed here. This methodology might be particularly worth pursuing in pathogenic agents' detection as false negatives could have important adverse consequences. In total, 15 ponds were found positive for Bd and four for Bsal. This study reports the first record of Bsal in Luxembourg.

Programme Dementia Prevention (pdp): A Nationwide Program for Personalized Prevention in Luxembourg.

BACKGROUND: With continuously aging societies, an increase in the number of people with cognitive decline is to be expected. Aside from the development of causative treatments, the successful implementation of prevention strategies is of utmost importance to reduce the high societal burden caused by neurodegenerative diseases leading to dementia among which the most common cause is Alzheimer's disease. OBJECTIVE: The aim of the Luxembourgish "programme dementia prevention (pdp)" is to prevent or at least delay dementia in an at-risk population through personalized multi-domain lifestyle interventions. The current work aims to provide a detailed overview of the methodology and presents initial results regarding the cohort characteristics and the implementation process. METHODS: In the frame of the pdp, an extensive neuropsychological evaluation and risk factor assessment are conducted for each participant. Based on the results, individualized multi-domain lifestyle interventions are suggested. RESULTS: A total number of 450 participants (Mean age = 69.5 years; SD = 10.8) have been screened at different recruitment sites throughout the country, among whom 425 participants (94.4%) met the selection criteria. CONCLUSIONS: We provide evidence supporting the feasibility of implementing a nationwide dementia prevention program and achieving successful recruitment of the target population by establishing a network of different healthcare providers.

The MEDITAGING study: protocol of a two-armed randomized controlled study to compare the effects of the mindfulness-based stress reduction program against a health promotion program in older migrants in Luxembourg.

BACKGROUND: Migration is a phenomenon worldwide, with older migrants, particularly those with fewer socioeconomic resources, having an increased risk of developing adverse cognitive and health outcomes and social isolation. Therefore, it is of utmost importance to validate interventions that promote healthy aging in this population. Previous studies have shown a positive impact of mindfulness based-stress reduction (MBSR) on outcomes such as cognition and sleep. However, only a few studies verified its potential in older adults, especially with vulnerable populations such as migrants. This article presents the protocol of the MEDITAGING study, which is the first to investigate the MBSR effects in migrants aged ≥55 in comparison to a health promotion program. METHODS: MEDITAGING is a two-arm randomized, double-blinded, controlled study, which will include older Portuguese-speaking migrants (n = 90). Participants are randomized to the MBSR or a health promotion program. Both interventions are conducted in groups over a total of 8 weeks, incorporating weekly meetings, an additional 4-hour class, and extra at-home tasks. The health promotion program has the same structure as the MBSR but comprises different activities related to dementia prevention, healthy habits, cognitive stimulation, sleeping, nutrition, watercolor painting, and physical activity. The assessment of executive functioning, physiological stress measures, self-reported questionnaires, and qualitative interviews are conducted at baseline, after 8 weeks (post-intervention), and at a follow-up session (from one to 3 months thereafter). Analyzes will be conducted using a modified intention-to-treat approach (all participants with at least 3 days of participation in the group-sessions and one post-intervention observation). DISCUSSION: This study will test effects of a mindfulness-based intervention against an active control condition in older adult migrants, which few studies have addressed. TRIAL REGISTRATION: ClinicalTrials.gov NCT05615337 (date of registration: 27 September 2022; date of record verification: 14 November 2022).

Risk and protective factors of mental health in children in residential care: A nationwide study from Luxembourg.

BACKGROUND: Children who grow up in residential care are at high risk for mental health problems. Existing studies have focused on negative mental health indicators and risk factors. There has been less emphasis on identifying protective factors, particularly those associated with positive mental health outcomes. OBJECTIVE: This study explores positive and negative dimensions of mental health and their links to risk and protective factors in children who have experienced early adversity and trauma and have been placed in residential care. PARTICIPANTS AND SETTINGS: Children aged 11 to 18 (N = 264) were recruited from residential care homes in Luxembourg, a small, high-income European country. METHODS: The children completed self-report questionnaires on mental health, perceived stress, school pressure, and participation. Residential care workers provided information on demographic factors, developmental and care history, and pre-care experiences of early adversity and trauma. RESULTS: Confirmatory factor analysis indicated that subjective well-being, internalising problems, and externalising problems are separate yet interconnected components of mental health. Multiple Indicators Multiple Causes models showed that individual, contextual, and psychosocial predictors contribute differentially to positive and negative mental health outcomes. CONCLUSIONS: Using a national sample of children in residential care in Luxembourg, this research indicates that subjective well-being, internalising problems, and externalising problems are distinct but related aspects of mental health. 'Child participation' and 'school pressure' displayed strong links with positive mental health outcomes and may serve as a potential path for improving public health interventions for children in care.

Effective tax rates of multinational corporations: Country-level estimates.

Effective tax rates (ETRs) estimated from the income statement data of multinational corporations (MNCs) are useful for comparing MNCs' corporate income taxation across countries. In this paper, we propose a new methodological approach to estimate ETRs as reliably and for as many countries as possible using Orbis' unconsolidated data for the 2011-2015 period. We focus on countries with at least 50 available companies, which results in a sample of 47, mostly European, countries. We estimate the ETR of a country as the ratio of corporate income tax to gross income for all affiliates of MNCs in that country, weighted by gross income. We propose four ETR estimations, including lower and upper bounds, which differ by gross income calculation. We find that ETRs substantially differ from statutory tax rates for some countries. For example, we show that despite similar statutory rates of 28% and 29%, MNCs in Luxembourg paid as little as 1-8% of gross income in taxes, while those in Norway paid as much as 46-67%. Despite being the best available, existing data is still imperfect. We therefore call for better data in the form of MNCs' unconsolidated, public country-by-country reporting data.

Nickel in foodstuffs available on the Luxembourgish market and dietary intake.

Nickel is a food contaminant of natural or anthropogenic origin. Monitoring of contaminants in food in general allows obtaining an overview on the presence of substances that are undesirable to health. The aim of this study was to analyse nickel content in food of non-animal origin and beverages sold in Luxembourg to determine the exposure of the population to this contaminant. In total, 660 samples were analysed in the timeframe from 2017 to 2021. The results demonstrate high concentrations of nickel in cashew nuts, walnuts, hemp and sunflower seeds, dried peas, oregano, and cocoa powder. Surveillance of contaminants in food allows identifying contributors to the chronic and acute exposure of nickel in order to potentially set official maximum levels in European legislation in the future, allowing for better enforcement actions in case of contaminated products and increasing consumer protection.

Douglas-fir plantations impact stream and groundwater chemistry in western Europe: Insights from three case studies in France and Luxembourg.

In rural areas, nitrate concentrations in surface waters most often originate from the leaching of excess N fertilizer in agricultural lands, whereas forested catchments often have good water quality. However, Douglas-fir plantations may induce nitrogen cycle unbalances which may lead to an excess of nitrate production in the soil. We hypothesize that the excess of production of nitrate in the soil and nitrate leaching to streamwater is greater in catchments planted with Douglas fir. We used paired catchments in both France and Luxembourg with different land covers (Douglas-fir, Spruce, Deciduous, Grassland and clearcut) which were monitored over a 3-5 year period in order to assess the effect of Douglas-fir plantations on the chemical composition of surface water. Nitrate concentration in the soil and groundwater were also monitored. The results show that nitrate concentrations in streams draining Douglas-fir catchments were two to ten times higher than in streams draining other land covers, but were similar to the clearcut catchment. Nitrate concentrations under Douglas-fir in groundwater (up to 50 mg L-1) and in the soil were also higher than under all other land covers. Soil nitrate concentration was related to stream nitrate concentration. This suggests that soil processes, through excessive nitrate production under Douglas-fir, are driving the nitrate concentration in the stream water and our hypothesis of a transfer of a fairly large proportion of this excessive production from the soil to the stream is supported. This study also shows that nitrate concentrations in surface and ground waters in rural areas could also originate from Douglas fir forested catchments. The impact of Douglas-fir is nevertheless reduced downstream through a dilution effect: mixing tree species at the catchment scale could thus be a solution to mitigate the effect of Douglas-fir on nitrate concentration in surface waters.

Ten-Year Changes in the Physical Activity and Sedentary Behaviors of Adults: An Analysis of the 2 Cross-Sectional Observation of Cardiovascular Risk Factors in Luxembourg Studies.

BACKGROUND: Monitoring population physical activity (PA) and sedentary behavior over time is important to guide public health actions. The objective of this study was to investigate the changes in PA and sedentary behavior of adult residents in Luxembourg over 10 years. We also investigated variations in change over time across sociodemographic subgroups. METHODS: Two population-based cross-sectional studies of adults living in Luxembourg (Observation of Cardiovascular Risk Factors in Luxembourg [ORISCAV-LUX] [2007-2008] and ORISCAV-LUX 2 [2016-2018]) were considered. Multilevel mixed-effects models were used to investigate changes over time between the studies with regard to self-reported total PA (metabolic equivalent of task-min/week), PA levels (inactive/sufficiently active/highly active), total sitting time, recreational television viewing, and personal computer (PC) use outside of work (in minutes per day). RESULTS: The ORISCAV-LUX study included 1318 participants and the ORISCAV-LUX 2 study involved 1477 participants; 573 adults took part in both studies. The proportion of participants categorized as highly active increased over time by 6.9%. Total PA (761 metabolic equivalent of task-min/wk), television viewing (12 min/d), and PC use outside of work (13 min/d) also increased, whereas the total sitting time decreased by 25 minutes per day. Variations in change over time were observed by sex, country of birth, education, employment status, and perceived financial difficulty. CONCLUSIONS: Over a 10-year period, PA increased and total sitting time decreased in adults living in Luxembourg. With regard to specific sedentary behaviors, television viewing, and PC use outside of work increased. Specific population subgroups will benefit the most from targeted efforts to increase PA and minimize sedentary behavior.

P23-A137†Cross-border cooperation for corneal donation between lions eye bank Saar-Lor-Lux, Trier/Westpfalz in Homburg/Saar and Luxembourg.

PURPOSE: With the increasing demand for corneas, eye banks must optimize and extend their sources of tissue donation. On the other hand, corneal transplantation is a specialized procedure performed in hospitals with high quality standards and ideally an integrated eye bank. In this report we would like to focus on an international win-win-win agreement between the Department of Ophthalmology at Saarland University Medical Center (Homburg/Saar, Germany), the LIONS Eye Bank Saar-Lor-Lux, Trier/Westpfalz and the four major non-university hospitals without corneal transplantation competence in Luxembourg. METHODS: In 2012, at the initiative of the Luxembourgish Ministry of Health and Department of Ophthalmology (Homburg/Saar, Germany), an international agreement was established with the Centre Hospitalier du Luxembourg (Luxembourg). Administrative and legislative rules were developed. Luxembourgish nursing personnel attended a practical training program for corneal excision at the Department of Ophthalmology in Homburg/Saar allowing them to harvest the two first corneal donors on site by themselves during the first year. In the following years two more hospitals, the Centre Hospitalier Emile Mayrisch (Esch-sur-Alzette, Luxembourg) and the Hôpitaux Robert Schuman (Kirchberg, Luxembourg), joined the cooperation. RESULTS: From 2012 until 2021, three hospitals in Luxembourg donated 779 corneas to the LIONS Eye Bank of the Saarland University Medical Center in Homburg/Saar (Germany). In return, 308 Luxembourgish patients have received a corneal transplantation at the Department of Ophthalmology in Homburg/Saar. In 2022, the extension continued and an agreement with a fourth hospital in Luxembourg at the Centre Hospitalier du Nord (Ettelbruck, Luxembourg) was signed providing even more donations. CONCLUSION: The cross-border collaboration for corneal donation and patient treatment has proven to be successful with both numbers of harvested donors and transplanted patients rising. However, international legislation for tissue donation needs to be accurately respected and a quality management system established to provide continuous quality of the donor tissue.

Environmental dynamics of Campylobacter jejuni genotypes circulating in Luxembourg: what is the role of wild birds?

Campylobacter jejuni is the leading cause of bacterial gastroenteritis worldwide, but, unlike other foodborne pathogens, is not commonly reported as causing outbreaks. The population structure of the species is characterized by a high degree of genetic diversity, but the presence of stable clonally derived genotypes persisting in space and time, and potentially leading to diffuse outbreaks, has recently been identified. The spread of these recurring genotypes could be enhanced by wild birds, suspected to act as vectors for a wide range of microorganisms that can be transmissible to other animals or humans. This study assessed the genetic diversity of C. jejuni carriage in wild birds and surface waters to explore a potential link between these environments and the persistence over years of recurring lineages infecting humans in Luxembourg. These lineages corresponded to over 40 % of clinical isolates over a 4 year period from 2018 to 2021. While mainly exotic genotypes were recovered from environmental samples, 4 % of C. jejuni from wild birds corresponded to human recurring genotypes. Among them, a human clinical endemic lineage, occurring for over a decade in Luxembourg, was detected in one bird species, suggesting a possible contribution to the persistence of this clone and its multi-host feature. Whereas 27 % of wild birds were carriers of C. jejuni, confirming their role as spreader or reservoir, only three out of 59 genotypes overlapped with recurring human strains. While direct transmission of C. jejuni infection through wild birds remains questionable, they may play a key role in the environmental spreading of stable clones to livestock, and this issue merits further investigation.

Old age takes its toll: Long-run projections of health-related public expenditure in Luxembourg.

This paper simulates long-term trends in Luxembourg's public expenditure on healthcare and on long-term care. We combine population projections with micro-simulations of individuals' health status that account for their demographic, socio-economic characteristics and their childhood circumstances. Model equations estimated on data from the SHARE survey and from several branches of Social Security provide a rich framework to study policy-relevant applications. We simulate public expenditure on healthcare and long-term care under different scenarios to evaluate the separate contributions of population ageing, costs of producing health-related services, and the distribution of health status across age cohorts. Results suggest that rising per capita expenditure on healthcare will mostly result from production costs, while rising expenditure on long-term care will mostly reflect population ageing.

Nine-year exposure to residential greenness and the risk of metabolic syndrome among Luxembourgish adults: A longitudinal analysis of the ORISCAV-Lux cohort study.

Growing evidence shows a beneficial effect of exposure to greenspace on cardiometabolic health, although limited by the cross-sectional design of most studies. This study examined the long-term associations of residential greenness exposure with metabolic syndrome (MetS) and MetS components within the ORISCAV-LUX study (Wave 1: 2007-2009, Wave 2: 2016-2017, n = 395 adults). Objective exposure to residential greenness was measured in both waves by the Soil-Adjusted Vegetation Index (SAVI) and by Tree Cover Density (TCD). Linear mixed models were fitted to estimate the effect of baseline levels and change in residential greenness on MetS (continuous score: siMS score) and its components (waist circumference, triglycerides, HDL-cholesterol, fasting plasma glucose and systolic blood pressure), respectively. This study provides evidence that an increase in SAVI, but not TCD, may play a role in preventing MetS, as well as improving HDL-cholesterol and fasting plasma glucose levels. Greater baseline SAVI was also associated with lower fasting plasma glucose levels in women and participants living in municipalities with intermediate housing price, and greater baseline TCD was associated with larger waist circumference. Overall, findings suggest a mixed impact of increased greenness on cardiometabolic outcomes. Further longitudinal research is needed to better understand the potential effects of different types of greenness exposure on cardiometabolic outcomes.

Tick findings from subterranean environments in the Central German Uplands and Luxembourg reveal a predominance of male Ixodes hexagonus.

Questing ticks are usually collected by flagging or dragging. Mostly exophilic tick species are caught, such as Ixodes ricinus, the most common tick in Central Europe. In the present study, ticks collected from underground environments in the Grand Duchy of Luxembourg and in the Central German Uplands (Federal States of Hesse, Bavaria, Thuringia, Baden-Wuerttemberg, Rhineland-Palatinate, Saarland and Northrhine-Westphalia) were investigated. Six tick species were revealed among the 396 analyzed specimens: Ixodes ariadnae, Ixodes canisuga, Ixodes hexagonus, I. ricinus, Ixodes trianguliceps, and Dermacentor marginatus. Adults and immatures of I. hexagonus dominated the findings (57% of all specimens), especially in shelters acting as potential resting places of main hosts. Ixodes canisuga and I. trianguliceps were for the first time recorded in Luxembourg, and one nymph of the bat tick I. ariadnae represents only the second report for Germany. Collecting ticks in subterranean environments turned out to be a useful approach to increase knowledge about the occurrence of relatively rare tick species, including those that spend most of their lifetime on their hosts, but detach in such environmental settings.

Real-world experience with isatuximab in the treatment of relapsed-refractory multiple myeloma: a case series from the Grand Duchy of Luxembourg.

BACKGROUND & OBJECTIVE: Anti-CD38 targeting has become an important pillar of the treatment for patients with multiple myeloma (MM). This evolution was spearheaded by daratumumab, but more recently isatuximab became the second CD38-directed monoclonal antibody to receive EMA approval for the treatment of patients with relapsed/refractory (RR) MM. In recent years, real-world studies have become increasingly important to confirm and solidify the clinical potential of novel anti-myeloma therapies. METHODS: This article describes the real-world experience with isatuximab-based therapy in a selection of four RRMM patients treated with an isatuximab-based treatment regimen in the Grand Duchy of Luxembourg. RESULTS: Three of the four cases described in this article consist of heavily pretreated patients who were previously exposed to daratumumab-based therapy. Interestingly, the isatuximab-based therapy provided clinical benefit to all three of these patients illustrating that prior exposure to an anti-CD38 mAb does not preclude a response to isatuximab. As such, these findings further support the design of larger prospective studies looking into the impact of prior daratumumab use on the efficacy of isatuximab-based therapy. In addition, two of the cases included in this report displayed renal insufficiency and the experience with isatuximab in these patients further supports the use of this agent in this setting. CONCLUSION: the clinical cases described illustrate the clinical potential of isatuximab-based treatment for RRMM patient in a real-world setting.

Parasites and their impact on thick-shelled river mussels Unio crassus from two populations in Luxembourg.

The thick-shelled river mussel Unio crassus Philipsson, 1788 is a species native to many European habitats, with declining populations. The impact of parasite communities on health status of this species is poorly understood. In this study, parasites of 30 U. crassus specimens from the Our and Sauer Rivers in Luxembourg were identified morphologically and, in some cases, using molecular genetic methods. The findings were correlated to selected parameters (total length, visceral weight, shell lesions, gonadal stage). The 2 populations did not differ in shell length, visceral weight, number of males and females, gonadal scoring, shell lesions, and the occurrence of glochidia. The prevalence and infestation intensities of detected Trichodina sp., Conchophthirus sp., and freshwater mite larvae did not differ between the 2 populations, whereas the prevalence and infestation intensities of mite eggs, nymphs, and adults were significantly higher in the Sauer River. Rhipidocotyle campanula and European bitterling Rhodeus amarus larvae were only present in the Sauer. Histopathology revealed the destruction of the gonads by R. campanula and tissue damage by the mites. The only significant correlation of the selected parameters was a positive correlation between R. amarus occurrence and total length as well as a negative correlation between R. amarus occurrence and gonadal stage. In the Sauer River, 2 mussels were found to be hermaphrodites.