Characteristics and outcomes of COVID-19 patients presumed to be treated with sotrovimab in NHS hospitals in England.

BACKGROUND: The impact of the constantly evolving severe acute respiratory syndrome coronavirus 2 on the effectiveness of early coronavirus disease 2019 (COVID-19) treatments is unclear. Here, we report characteristics and acute clinical outcomes of patients with COVID-19 treated with a monoclonal antibody (mAb; presumed to be sotrovimab) across six distinct periods covering the emergence and predominance of Omicron subvariants (BA.1, BA.2, and BA.5) in England. METHODS: Retrospective cohort study using data from the Hospital Episode Statistics database from January 1-July 31, 2022. Included patients received a mAb delivered by a National Health Service (NHS) hospital as a day-case, for which the primary diagnosis was COVID-19. Patients were presumed to have received sotrovimab based on NHS data showing that 99.98% of COVID-19-mAb-treated individuals received sotrovimab during the study period. COVID-19-attributable hospitalizations were reported overall and across six distinct periods of Omicron subvariant prevalence. Subgroup analyses were conducted in patients with severe renal disease and active cancer. RESULTS: Among a total of 10,096 patients, 1.0% (n = 96) had a COVID-19-attributable hospitalization, 4.6% (n = 465) had a hospital visit due to any cause, and 0.3% (n = 27) died due to any cause during the acute period. COVID-19-attributable hospitalization rates were consistent among subgroups, and no significant differences were observed across periods of Omicron subvariant predominance. CONCLUSIONS: Levels of COVID-19-attributable hospitalizations and deaths were low in mAb-treated patients and among subgroups. Similar hospitalization rates were observed whilst Omicron BA.1, BA.2, and BA.5 were predominant, despite reported reductions in in vitro neutralization activity of sotrovimab against BA.2 and BA.5.

Delimiting conditions under which natural organic matter can control Fe speciation and size in freshwaters.

Pollutant and nutrient mobility in natural waters is typically controlled by sorption onto the high surface area of colloidal particles, most of which may form by precipitation of Fe(III)(hydr)oxides. Therefore, prediction of the speciation and size of Fe is critical to managing water quality. Prediction from pH and dissolved oxygen (D.O.) saturation can fail because of Fe binding to natural organic matter (N.O.M.) in natural waters. We test the influence of environmental variables -temperature, illumination and mixing order of Fe and N.O.M. with D.O.- on the impact of N.O.M.. Differences in mixing order simulate Fe(II) mixing with N.O.M. in groundwater prior to emerging, in comparison to Fe(II) emerging into oxic surface waters containing N.O.M.. Fe speciation and size were measured in waters containing N.O.M. with and without D.O., but also a water to which N.O.M. and then D.O. were added sequentially. Without D.O. free Fe(II) bound to N.O.M. and became a filterable particle. Binding increased with pH and at 7.5 was sufficient for Fe speciation in oxic waters to become influenced by whether mixing had been sequential or simultaneous. Therefore, at high pH Fe speciation in oxic surface waters requires knowledge of N.O.M. content of this water and upstream groundwaters. Cold (10 °C) decreased anoxic binding of Fe(II) to N.O.M. and both cold and darkness alsodecreased Fe binding to N.O.M. under oxic conditions, because in both cases Fe(III)(hydr)oxide surfaces out-compete N.O.M. for binding Fe. Cold and darkness therefore overwhelm the effect of mixing order on oxic Fe speciation, and cold even makes the presence or absence of N.O.M. irrelevant. In the cold or dark, prediction of Fe speciation and size in surface waters may not require knowledge of N.O.M. content of upstream groundwaters. Furthermore, when cold, prediction may not even require knowledge of N.O.M. content of the surface waters.

Characteristics of nano-plastics in bottled drinking water.

Plastic pollution in water is threatening the environment and human health. Previous relevant studies mainly focus on macro and micro plastic pollutions and their characteristics. Little is known about the extent and characteristics of nano-scale plastics in our drinking water systems, mainly due to difficulties in their isolation and analysis. These nano-plastics may pose higher risk to human health than micro-plastics. Here we report the collection and analysis of organic nanoparticles from commercial bottled water of two brands. Novel nano-plastic particle imaging and molecular structure analysis techniques have been applied. The findings show the existence of organic nanoparticles, and a likely source has been identified to be the degradation of plastic water bottles.

Size Fractionation of Dissolved Organic Nitrogen in Peatland Fluvial Systems.

Understanding the nature and fate of nitrogen (N) in freshwater systems is crucial for assessing the risk of eutrophication. However, there is a paucity of information on the characterization of fluvial N in upland peat-dominated environments. Here, we employ a combination of field sampling and tangential flow ultrafiltration (TFU) to investigate the concentrations and fluxes of low molecular weight (LMW) and high molecular weight (HMW) dissolved organic N (DON) in a peatland stream-reservoir system in the south Pennines (UK). Our TFU results show that ∼26% of DON concentration is LMW DON and represents an estimated fluvial flux of 3.07 ± 22 kg N ha-1 during the study period. Our mass balance results reveal that the reservoir retains 71% of LMW DON input, which accounts for ∼25% retention of bioavailable (dissolved inorganic N + LMW DON) N. Our study suggests that current understanding of inorganic N as the sole source of bioavailable N with eutrophic significance in upland freshwaters requires a reappraisal. Evaluation of ecosystem response to increased loading of N needs to include a consideration of LMW DON.

Subsurface interactions of Fe(II) with humic acid or landfill leachate do not control subsequent iron(III) (hydr)oxide production at the surface.

At least 93% of Fe(II) remained free, as defined by ferrozine assay under anoxic conditions in the presence of humic acid (HA) and two simulated landfill leachates of different maturities. However, tangential flow ultrafiltration showed a weaker but more extensive interaction of Fe with organic carbon (OC); 90% of Fe associated with the less mature leachate. Despite the existence of this weak interaction under anoxic conditions, there was no difference in iron(III) (hydr)oxide production whether HA was added prior to or coincident with the oxidation of Fe(II) on exposure to oxic conditions. Under oxic conditions ferrozine showed that more Fe(II) bound to OC, up to 50% to HA. However, this occurs via oxidation of Fe(II) to Fe(III), which is bound and then thermally reduced. This affinity for Fe(III) and the ability to carry out thermal reduction both increase with the maturity of the OC. The rate at which ferrozine-defined free Fe(II) was lost on exposure to dissolved oxygen was also enhanced by the more mature OC, while it was slowed by acetogenic leachate. The slowing must be a consequence of the filtration-defined Fe(II)/OC interaction.

Toxicity of aluminium in natural waters controlled by type rather than quantity of natural organic matter.

Extension of the conditions under which Al toxicity is tested is required. Environmentally representative preparation of waters is used in investigating roles of alginate (AA) and humic acids (HA) in partitioning of Al (0.5 mg L(-1)), subsequent uptake and accumulation by and toxicity to Lymnaea stagnalis. HA and AA did not alter precipitation of Al(OH)3, but altered subsequent behaviour of Al. High (40 mg L(-1)) HA concentrations, and to a lesser extent AA, prevented settling and availability for benthic grazing but made deposited Al more likely to be ingested. HA detoxified but AA increased toxicity relative to Al alone. Low concentration (4 mg L(-1)) AA and HA do not change partitioning but increase uptake; they both detoxify, but AA less than HA. The study shows OC:Al ratio is critical in predicting Al behaviour in natural waters, also uptake is mediated by snail behaviour, not solely a function of concentration and form of Al. Therefore, predicting Al behaviour will be subject to errors in determining relevant water composition and response of biota to the new speciation. However, with respect to toxicity, rather than other aspects of Al behaviour, different ratios of HA and Al are insignificant compared to whether AA is present rather than HA.

Oxidation state and size of Fe controlled by organic matter in natural waters.

In a well mixed-stream, in which the iron/organic carbon (OC) ratio varied from 0.333 to 0.05 with sampling point and discharge, 40-70% of the Fe load was found to be present as lightly bound Fe(II). In laboratory simulations of streamwater, after 24 h of aeration at pH 6.5, and with an Fe/OC concentration ratio of 0.417, 97% of Fe(II) was converted to Fe(III) (hydr)oxides, while at a ratio of 0.083, 87% of Fe(ll) remained unoxidized. The particle size distribution of Fe contained < 0.2 microm fractions only when OC was present and comparison of Fe and OC size distributions suggested that there was more than one mechanism by which colloidal Fe was produced. At high Fe/ OC ratios, < 0.2 microm fractions may be predominantly Fe(III) (hydr)oxides stabilized by OC, but at low ratios, they must consist of otherwise soluble Fe(ll) attached to < 0.2 microm OC. The recognition in the field of the consequences of processes demonstrated in the laboratory suggests that OC may be a predominant control of both size and oxidation state of Fe in many natural waters.

Experimental studies of the influence of grain size, oxygen availability and organic carbon availability on bioclogging in porous media.

Changes in the hydraulic properties of porous material due to bioclogging have been observed in many laboratory simulations and field studies. Because such changes in hydraulic properties influence the movement of fluids and contaminants, microbial ecology data are required for improved transport modeling. Here we investigate the effects of environmental variables previously shown to influence bioclogging, specifically oxygen availability, sediment grain size, and organic carbon (nutrient) concentration on the hydraulic properties of simulated subsurface environments. Our study provides evidence of a different clogging mechanism for aerobic and anaerobic microbial communities under high organic carbon concentrations (400 mg L(-1)). This work also suggests that the clogging mechanism operating in anaerobic microbial communities is more sensitive to carbon availability than that in the aerobic microbial communities. We found that grain size does have an effect on clogging, but it appears that there is a threshold carbon concentration, and therefore biomass, below which these effects are insignificant. Differences between the microbial communities that developed under different oxygenation conditions were detected using 16s rRNA analysis.

Microbial controls on metal mobility under the low nutrient fluxes found throughout the subsurface.

Laboratory simulations and field studies of the shallow subsurface have shown that microbes and their extracellular products can influence the mobility of toxic metals from waste disposal sites. Modelling the transport of contaminants in groundwater may, therefore, require the input of microbial ecology data in addition to geochemical data, thus increasing the costs and the uncertainty of predictions. However, whether microbial effects on contaminant mobility occur extensively in the natural subsurface is unknown because the conditions under which they have been observed hitherto are generally unrepresentative of the average subsurface environment. Here, we show that microbial activity affects the mobility of a toxic trace metal (Cu) under the relatively low nutrient fluxes that dominate subsurface systems. More particularly, we show that under these low nutrient conditions, microbes and microbial products can immobilize metal but may themselves be subject to subsequent mobilization, thus complicating the pattern of metal storage and release. Our results show that the capability of microbes in the subsurface to change both the capacity of porous media to store metal, and the behaviour of metal that is released, is not restricted to the well researched environments close to sites of waste disposal. We anticipate our simulations will be a starting point for generating input data for transport models, and specifying the mechanism of metal remobilisation in environments more representative of the subsurface generally.