Antimicrobial resistance of Escherichia coli isolated from freshwaters and hospital effluents in Belgium.

The purpose of this work was to evaluate the level of antimicrobial resistant Escherichia coli isolates in freshwaters and hospital effluents in Belgium. The samples were collected from 24 locations along the Ourthe, Vesdre, Amblève and Meuse rivers and in the wastewater effluents of several hospitals. The sampling stations in rivers were classified according to the dominant land covers of the rivers (rural, urban and forest areas). Two sampling campaigns were organized in May and October 2019 to highlight a possible seasonal effect. A total of 938 E. coli strains were isolated on Chromogenic Selective Tryptone Bile X-glucuronide (TBX) and TBX supplemented with amoxicillin (TBX+AMX) media. Disk diffusion assays were performed following the EUCAST's recommendations to assess the antimicrobial resistance against 12 antibiotics. A total of 32·7% of strains were at least resistant to one antibiotic and 24·6% were multiple antimicrobial resistant strains on TBX. The highest resistance rates were found for ampicillin (AMP), amoxicillin coupled with clavulanic acid (AMC) and sulfamethoxazole/trimethoprim (SXT). The lowest resistance rates were observed for meropenem (MEM) and ertapenem (ETP), which are last resort antibiotics. No significant difference was observed between both campaigns for the resistance rate to antibiotics.

Occurrence of greenhouse gases in the aquifers of the Walloon Region (Belgium).

This work aims to (1) identify the most conductive conditions for the generation of greenhouses gases (GHGs) in groundwater (e.g., hydrogeological contexts and geochemical processes) and (2) evaluate the indirect emissions of GHGs from groundwater at a regional scale in Wallonia (Belgium). To this end, nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2) concentrations and the stable isotopes of nitrate (NO3-) and sulphate were monitored in 12 aquifers of the Walloon Region (Belgium). The concentrations of GHGs range from 0.05µg/L to 1631.2µg/L for N2O, 0µg/L to 17.1µg/L for CH4, and 1769 to 100,514ppm for the partial pressure of CO2 (pCO2). The highest average concentrations of N2O and pCO2 are found in a chalky aquifer. The coupled use of statistical techniques and stable isotopes is a useful approach to identify the geochemical conditions that control the occurrence of GHGs in the aquifers of the Walloon Region. The accumulation of N2O is most likely due to nitrification (high concentrations of dissolved oxygen and NO3- and null concentrations of ammonium) and, to a lesser extent, initial denitrification in a few sampling locations (medium concentrations of dissolved oxygen and NO3-). The oxic character found in groundwater is not prone to the accumulation of CH4 in Walloon aquifers. Nevertheless, groundwater is oversaturated with GHGs with respect to atmospheric equilibrium (especially for N2O and pCO2); the fluxes of N2O (0.32kgN2O-NHa-1y-1) and CO2 (27kgCO2Ha-1y-1) from groundwater are much lower than the direct emissions of N2O from agricultural soils and fossil-fuel-related CO2 emissions. Thus, indirect GHG emissions from the aquifers of the Walloon Region are likely to be a minor contributor to atmospheric GHG emissions, but their quantification would help to better constrain the nitrogen and carbon budgets.

HPV vaccination coverage in the federal state of Belgium according to regions and their impact.

Long-term results of the HPV vaccination programs in Australia and Scotland have shown a tremendous impact on the reduction of HPV infection rates and precancerous diseases. Both countries started mass vaccination ten years (Australia) and eight years (Scotland) ago and achieved a vaccination coverage of more than 80 %. Within 20 to 30 years a reduction in cervical cancer by more than 75 % is expected. Furthermore, there will be a reduction in other HPV related cancers like vaginal, vulva, perineal, anal and oropharyngeal cancers. In order to be successful, a high vaccination coverage is needed. In Belgium, the vaccination was introduced in 2010 in the Flemish community and in 2011 in the French community. In the first vaccinated cohorts the coverage in Flemish and French Communities was respectively 84% (2010) and 29% (2012-2013). The latest data suggest that the Flemish Community (Flanders Region) attained a coverage of 91 % while the French Community (Walloon Region) attained a coverage of around 36 %. The regional difference in coverage offers a real-life case. The worst-case scenario could end up with proportionally one half of country having more HPV related cancers than the other half. Currently efforts are performed to increase the coverage rates in both regions and consequently decreasing this difference. Additionally, the updated recommendations regarding the HPV vaccination by the Belgian NITAG (National Immunization Technical Advisory Group) stated that the HPV vaccination should be gender neutral. This could stimulate the vaccination program and increase the coverage. The coverage rate in Flanders is among the highest in the world and the rate in the French Community is increasing. Efforts should be continued in order to maintain trust and increase the coverage rate.

Log-normality of indoor radon data in the Walloon region of Belgium.

The deviations of the distribution of Belgian indoor radon data from the log-normal trend are examined. Simulated data are generated to provide a theoretical frame for understanding these deviations. It is shown that the 3-component structure of indoor radon (radon from subsoil, outdoor air and building materials) generates deviations in the low- and high-concentration tails, but this low-C trend can be almost completely compensated by the effect of measurement uncertainties and by possible small errors in background subtraction. The predicted low-C and high-C deviations are well observed in the Belgian data, when considering the global distribution of all data. The agreement with the log-normal model is improved when considering data organised in homogeneous geological groups. As the deviation from log-normality is often due to the low-C tail for which there is no interest, it is proposed to use the log-normal fit limited to the high-C half of the distribution. With this prescription, the vast majority of the geological groups of data are compatible with the log-normal model, the remaining deviations being mostly due to a few outliers, and rarely to a "fat tail". With very few exceptions, the log-normal modelling of the high-concentration part of indoor radon data is expected to give reasonable results, provided that the data are organised in homogeneous geological groups.

Homogenity of geological units with respect to the radon risk in the Walloon region of Belgium.

In the process of mapping indoor radon risk, an important step is to define geological units well-correlated with indoor radon. The present paper examines this question for the Walloon region of Belgium, using a database of more than 18,000 indoor radon measurements. With a few exceptions like the Carboniferous (to be divided into Tournaisian, Visean and Namurian-Westphalian) and the Tertiary (in which all Series may be treated together), the Series/Epoch stratigraphic level is found to be the most appropriate geological unit to classify the radon risk. A further division according to the geological massif or region is necessary to define units with a reasonable uniformity of the radon risk. In particular, Paleozoic series from Cambrian to Devonian show strong differences between different massifs. Local hot-spots are also observed in the Brabant massif. Finally, 35 geological units are defined according to their radon risk, 6 of which still present a clear weak homogeneity. In the case of 4 of these units (Jurassic, Middle Devonian of Condroz and of Fagne-Famenne, Ordovician of the Stavelot massif) homogeneity is moderate, but the data are strongly inhomogeneous for Visean in Condroz and in the Brabant massif. The 35 geological units are used in an ANOVA analysis, to evaluate the part of indoor radon variability which can be attributed to geology. The result (15.4-17.7%) agrees with the values observed in the UK.