[Lead in drinking water-an old problem, a new EU directive]. / Blei im Trinkwasser ­ ein altes Problem, eine neue EU-Richtlinie.

BACKGROUND: Lead pipes have been used in drinking water installations for a long time. Only since 1973 have their use in new buildings been strongly discouraged; nevertheless, they are still found in old buildings. Furthermore, lead-containing alloys are still used today in components such as fittings. This results in an avoidable pollution of drinking water. The health significance of this pollution is acknowledged by a reduction of the currently valid limit value from 10 µg/l to 5 µg/l by the new EU drinking water directive passed in 2020. This directive provides for a transition period of 15 years. OBJECTIVES: The relevance of a stricter limit value for lead in drinking water will be evaluated based by the results of routine analyses, and the necessary public health measures to prevent exposure of vulnerable groups will be formulated. MATERIAL AND METHODS: A retrospective analysis of routine samples from the city of Bonn, which an accredited drinking water laboratory had examined in the years 1997-2019, was performed. RESULTS: Of the 16,060 samples analyzed, 75.36% were below the quantitative limit of quantification. The median of the quantifiable samples was above the future limit for lead in drinking water in each year considered. No effect of the last transition period of 10 years (2003-2013) could be detected. DISCUSSION: Even though no systematic studies on lead pollution in German municipalities are available, the subject is still highly topical. Lead exposure from drinking water installations is a completely avoidable health risk, but it can only be regulated by consistent enforcement of the applicable rules by the health authorities. The health authorities must be adequately equipped in terms of personnel, material, and financial resources.

Investigation of Three Different UV-C Irradiation Schemes for Bacterial Decontamination of FFP2 Masks to Make Them Reusable.

The effect of filtering face piece grade 2 (FFP2) masks for infection prevention is essential in health care systems; however, it depends on supply chains. Efficient methods to reprocess FFP2 masks may be needed in disasters. Therefore, different UV-C irradiation schemes for bacterial decontamination of used FFP2 masks were investigated.Seventy-eight masks were irradiated with UV light for durations between 3 and 120 seconds and subsequently analyzed for the presence of viable bacteria on the inside. Ten masks served as the control group. Irradiation on the inside of the masks reduced bacteria in proportion to the dose, with an almost complete decontamination after 30 seconds. Outside irradiation reduced the quantity of colonies without time-dependent effects. Both sides of irradiation for a cumulated 30 seconds or more showed almost complete decontamination.Overall, this study suggests that standardized UV irradiation schemes with treatment to both sides might be an efficient and effective method for FFP2 mask decontamination in times of insufficient supplies.

Examining Different Analysis Protocols Targeting Hospital Sanitary Facility Microbiomes.

Indoor spaces exhibit microbial compositions that are distinctly dissimilar from one another and from outdoor spaces. Unique in this regard, and a topic that has only recently come into focus, is the microbiome of hospitals. While the benefits of knowing exactly which microorganisms propagate how and where in hospitals are undoubtedly beneficial for preventing hospital-acquired infections, there are, to date, no standardized procedures on how to best study the hospital microbiome. Our study aimed to investigate the microbiome of hospital sanitary facilities, outlining the extent to which hospital microbiome analyses differ according to sample-preparation protocol. For this purpose, fifty samples were collected from two separate hospitals-from three wards and one hospital laboratory-using two different storage media from which DNA was extracted using two different extraction kits and sequenced with two different primer pairs (V1-V2 and V3-V4). There were no observable differences between the sample-preservation media, small differences in detected taxa between the DNA extraction kits (mainly concerning Propionibacteriaceae), and large differences in detected taxa between the two primer pairs V1-V2 and V3-V4. This analysis also showed that microbial occurrences and compositions can vary greatly from toilets to sinks to showers and across wards and hospitals. In surgical wards, patient toilets appeared to be characterized by lower species richness and diversity than staff toilets. Which sampling sites are the best for which assessments should be analyzed in more depth. The fact that the sample processing methods we investigated (apart from the choice of primers) seem to have changed the results only slightly suggests that comparing hospital microbiome studies is a realistic option. The observed differences in species richness and diversity between patient and staff toilets should be further investigated, as these, if confirmed, could be a result of excreted antimicrobials.

SARS-CoV-2 in Environmental Samples of Quarantined Households.

The role of environmental transmission of SARS-CoV-2 remains unclear. Thus, the aim of this study was to investigate whether viral contamination of air, wastewater, and surfaces in quarantined households result in a higher risk for exposed persons. For this study, a source population of 21 households under quarantine conditions with at least one person who tested positive for SARS-CoV-2 RNA were randomly selected from a community in North Rhine-Westphalia in March 2020. All individuals living in these households participated in this study and provided throat swabs for analysis. Air and wastewater samples and surface swabs were obtained from each household and analysed using qRT-PCR. Positive swabs were further cultured to analyse for viral infectivity. Out of all the 43 tested adults, 26 (60.47%) tested positive using qRT-PCR. All 15 air samples were qRT-PCR-negative. In total, 10 out of 66 wastewater samples were positive for SARS-CoV-2 (15.15%) and 4 out of 119 surface samples (3.36%). No statistically significant correlation between qRT-PCR-positive environmental samples and the extent of the spread of infection between household members was observed. No infectious virus could be propagated under cell culture conditions. Taken together, our study demonstrates a low likelihood of transmission via surfaces. However, to definitively assess the importance of hygienic behavioural measures in the reduction of SARS-CoV-2 transmission, larger studies should be designed to determine the proportionate contribution of smear vs. droplet transmission.

LAMP-Seq enables sensitive, multiplexed COVID-19 diagnostics using molecular barcoding.

Frequent testing of large population groups combined with contact tracing and isolation measures will be crucial for containing Coronavirus Disease 2019 outbreaks. Here we present LAMP-Seq, a modified, highly scalable reverse transcription loop-mediated isothermal amplification (RT-LAMP) method. Unpurified biosamples are barcoded and amplified in a single heat step, and pooled products are analyzed en masse by sequencing. Using commercial reagents, LAMP-Seq has a limit of detection of ~2.2 molecules per µl at 95% confidence and near-perfect specificity for severe acute respiratory syndrome coronavirus 2 given its sequence readout. Clinical validation of an open-source protocol with 676 swab samples, 98 of which were deemed positive by standard RT-qPCR, demonstrated 100% sensitivity in individuals with cycle threshold values of up to 33 and a specificity of 99.7%, at a very low material cost. With a time-to-result of fewer than 24 h, low cost and little new infrastructure requirement, LAMP-Seq can be readily deployed for frequent testing as part of an integrated public health surveillance program.