Sciensano

Wastewater-based epidemiology (WBE) has emerged as a powerful tool for community monitoring, offering a non-invasive, cost-effective means of assessing public health. PCR-based methods, including digital droplet PCR (ddPCR), combined with reverse transcription (RT) for RNA viruses, are widely used for detection of known pathogens in wastewater. Recently, sequencing approaches have gained importance. Targeted amplicon sequencing enables high-sensitivity detection of specific pathogens, while metagenomic sequencing provides untargeted profiling of microbial and viral communities, supporting surveillance of novel pathogens and antimicrobial resistance (AMR). A major challenge across all genomic approaches remains the efficient concentration and extraction of nucleic acids, particularly for low-abundance targets like respiratory viruses. This study aimed to evaluate the fit-for-purpose of concentration and extraction protocols for wastewater surveillance, focussing on their suitability for genomic downstream applications: (RT-)ddPCR, amplicon sequencing and metagenomics. Both RNA (viral pathogens) and DNA (AMR markers) targets were included and experiments were performed on raw and spiked wastewater. The results revealed substantial variability in method performance. Ultrafiltration with a concentrating pipette (InnovaPrep) consistently yielded lower viral concentrations, whereas precipitation-based methods, magnetic capture and a column-based concentration/extraction kit provided higher yield and better sensitivity. PCR inhibitors reduced targeted sequencing efficiency, while metagenomics produced consistent taxonomic profiles across methods. Overall, the study highlights the importance of protocol optimization to improve sensitivity in WBE. Optimization of protocols, particularly for detecting low abundance pathogens and inhibitor removal, remains essential. Broader validation across diverse wastewater matrices and microbial species will be critical to strengthen the role of WBE in public health surveillance.

In this study, we evaluated the performance of FT-IR spectroscopy for clonality assessment of Serratia marcescens by comparing its clustering output to that of whole-genome sequencing (WGS), using core genome single nucleotide polymorphism (cgSNP) analysis as reference. A genetically diverse set of Serratia marcescens clinical isolates was collected from different hospitals in Belgium and measured with FT-IR spectroscopy in biological triplicate to assess reproducibility and in turn build a robust reference set. WGS data of the isolates was available and used to assess the performance of FT-IR spectroscopy. FT-IR spectroscopy showed good overall concordance with WGS (Adjusted Rand Index [ARI] of 0.755), but the level of agreement was insufficient to support the use of a single fixed cut-off value (COV) for clinical outbreak interpretation. To address this, a standardized workflow was developed incorporating multiple COVs to interpret clustering with varying level of confidence. This approach was validated using three unrelated S. marcescens outbreak case studies in neonatal intensive care units. The workflow yielded clustering results that matched WGS-based analyses and allowed clonality assessments within 24 h after isolate recovery. In conclusion, FT-IR spectroscopy can serve as a first-line screening tool to rapidly identify clonal clusters of S. marcescens, reducing turnaround time and limiting the number of isolates requiring confirmatory WGS, thereby considerably lowering overall outbreak investigation costs.

Arthroderma is a taxonomically diverse genus within the dermatophyte family (Onygenales, Arthrodermataceae) comprising primarily geophilic species typically found in animal burrows, where they feed on keratinous debris. In this study, species delineations within the genus were refined according to current taxonomic standards using the extensive array of Arthroderma strains of the BCCM/IHEM fungi collection. The methodology was based on a polyphasic approach including phenotypic analyses, multi-gene phylogenetic inference (comprising the internal transcribed spacer (ITS), β-tubulin (BT), and RNA polymerase II core subunit (RBP2) regions) and MALDI-TOF mass spectrometry. Special attention was given to the highly diverse A. quadrifidum clade which contains both geophilic and potentially zoophilic species, assessing the phylogenetic position of recently described taxa within this group. In total, 77 strains from the BCCM/IHEM collection were (re-)examined. MALDI-TOF mass spectrometry was able to correctly identify 92

Green space offers numerous benefits for health and well-being, yet socioeconomic disparities continue to shape who has access to these benefits. The 3+30+300 guideline aims to reduce this inequity by promoting visible, available, and accessible green for all residents. This study assesses these components of green exposure across Flanders, Belgium, one of the most densely populated and highly urbanized regions in Western Europe, and examines how they intersect with multiple dimensions of socioeconomic deprivation, namely sensitivity and adaptive capacity. Using 264,622 building-level sample points, we quantified tree visibility from street-view imagery, tree canopy cover, and network distance to accessible green space. Median values of 5.0 (urban) and 6.0 (rural) visible trees, 16.1% (urban) and 12.4% (rural) canopy cover, and distances of 367 (urban) and 548 (rural) meters to accessible green were observed. Deprived neighborhoods, particularly those characterized by housing and health deprivation, showed the highest sensitivity to lack of green spaces, while areas with more elderly and higher-income residents had consistently greater exposure. These results suggest that green exposure and socioeconomic susceptibility intersect and reinforce one another, producing compounded distributive injustice. The findings highlight the need for equity-oriented interpretation and implementation of the 3+30+300 guideline and call for targeted greening strategies that address structural environmental and health inequalities.

Group B Streptococcus (GBS) infection is a leading cause of neonatal morbidity. Maternal rectovaginal GBS colonization is a primary risk factor for early onset neonatal GBS infection. In Belgium, pregnant women are screened and, if positive or at risk of transmission, offered intrapartum antibiotic prophylaxis (IAP). We aimed to provide the first comprehensive overview of Belgian data and identify possible risk factors of maternal GBS colonization and neonatal infection. We calculated proportions of maternal screening, colonization and incidence of all neonatal GBS infections and identified their risk factors using log binomial regression from national registries’ data between 2012–2021. Of all women, 90.2