Geo-referenced simulations of E. coli in a sub-catchment of the Vecht River using a probabilistic approach.

The proportion of wild swimmers at non-official bathing sites has increased during the Covid-19 pandemic. Bathing water quality at designated sites is monitored through analysis of the concentration of fecal indicator bacteria such as E. coli. However, non-official sites are generally not monitored. In a previous work, steady state modelling of E. coli was achieved at catchment scale, enabling a comparison of expected concentrations along an entire catchment for longtime average. However, E. coli concentrations can vary over several orders of magnitude at the same monitoring site throughout the year. To capture the temporal variability of E. coli concentrations on the catchment scale, we extended the existing deterministic E. coli sub-module of the GREAT-ER (Geo-referenced Exposure Assessment tool for European Rivers) model for probabilistic Monte-Carlo simulations. Here, selected model parameters are represented by probability distributions instead of fixed values. Wastewater treatment plant (WWTP) emissions and diffuse emissions were parameterized using selected data from a previous monitoring campaign (calibration data set) and in-stream processes were modeled using literature data. Comparison of simulation results with monitoring data (evaluation data set) indicates that predicted E. coli concentrations well-represent median measured concentrations, although the range of predicted concentrations is slightly larger than the observed concentration variability. The parameters with the largest influence on the range of predicted concentrations are flow rate and E. coli removal efficiency in WWTPs. A comparison of predicted 90th percentiles with the threshold for sufficient bathing water quality (according to the EU Bathing Water Directive) indicates that year-round swimming at sites influenced by WWTP effluents is advisable almost nowhere in the study area. A refinement of the model can be achieved if quantitative relationships between the WWTP removal efficiency and both, the treatment technologies as well as the operating parameters are further established.

Mega festivals like MahaKumbh, a largest mass congregation, facilitated the transmission of SARS-CoV-2 to humans and endangered animals via contaminated water.

Our surrounding environment has been influenced by the COVID-19 pandemic situation. The second wave of COVID-19 in India has proven to be more devastating and aggressive than the first wave of the pandemic, which led to recognizing India as one of the world's topmost worst-hit nations considering >4000 fatalities reported in a single day in May 2021. Such "resurgence and acceleration" of COVID-19 transmission has been fuelled by the MahaKumbh festival and political mass gathering (elections rallies) events, where the COVID-19 protocols have been ignored by millions of pilgrims/followers. The present review discusses only the consequences of this year's MahaKumbh festivals, the largest religious mass gathering on earth, which was held during the COVID-19 pandemic in India, and its impact on both the spread of SARS-CoV-2 among participants and their families and its influence on the quality of the river Ganga. This article tries to give readers outside of India an overview of how much impact of any such single large gathering of any relgion in any part of the world can drive coronavirus infections and effectively commence the second/third wave outbreak with this case study. Furthermore, the religious large scale celebration are widely accepted through out the world that have played a significant role in the spread of the pandemic into remote villages and towns all over the subcontinent/world, thus affecting many areas with insufficient healthcare facilities that have been relatively spared. This review also highlights the potential risk of transmission from infected humans into the aquatic environment of the river Ganga. Besides the obvious relevance of SARS-CoV-2, a large variety of other water-related disease vectors (bacteria, viruses, and protozoa) stemming from visitors to the religious congregation were introduced into the upstream regions of the Ganga river. Their sheer number is assumed to have had a severe influence on its delicate ecosystem, including endangered mammals such as the river Dolphins. The detailed epidemiological and clinical study on transmission routes of SARS-CoV-2 is the need of the hour to understand the pathogenesis of RNA virus infection and prevent the massive spreading of such infectious respiratory diseases. An interdisciplinary approach, rooted in evidence-based efficient learning, contextual strategies, and a streamlined unified approach should be adopted to help in the development of a proactive prevention model during future MahaKumbh festival (and similar religious gatherings) instead of just "picking up the pieces" in a conventional post-event model.

Extended Ecological Restoration of Bacterial Communities in the Godavari River During the COVID-19 Lockdown Period: a Spatiotemporal Meta-analysis.

The unprecedented COVID-19 pandemic has had major impact on human health worldwide. Whilst national and international COVID-19 lockdown and travel restriction measures have had widespread negative impact on economies and mental health, they may have beneficial effect on the environment, reducing air and water pollution. Mass bathing events (MBE) also known as Kumbh Mela are known to cause perturbations of the ecosystem affecting resilient bacterial populations within water of rivers in India. Lockdowns and travel restrictions provide a unique opportunity to evaluate the impact of minimum anthropogenic activity on the river water ecosystem and changes in bacterial populations including antibiotic-resistant strains. We performed a spatiotemporal meta-analysis of bacterial communities of the Godavari River, India. Targeted metagenomics revealed a 0.87-fold increase in the bacterial diversity during the restricted activity of lockdown. A significant increase in the resilient phyla, viz. Proteobacteria (70.6%), Bacteroidetes (22.5%), Verrucomicrobia (1.8%), Actinobacteria (1.2%) and Cyanobacteria (1.1%), was observed. There was minimal incorporation of allochthonous bacterial communities of human origin. Functional profiling using imputed metagenomics showed reduction in infection and drug resistance genes by - 0.71-fold and - 0.64-fold, respectively. These observations may collectively indicate the positive implications of COVID-19 lockdown measures which restrict MBE, allowing restoration of the river ecosystem and minimise the associated public health risk.