ABSTRACT
The quality of wastewater and the socioeconomic aspects of the life of the population are shown to be interrelated. It is proposed to use municipal wastewater to diagnose the health of the population, to assess the feeding preferences of city dwellers, the use of alcohol, tobacco, medicines, and drugs, to assess the exposure of the population to the effect of hazardous chemicals (PAH, pesticides, preserving agents, plasticizers, etc.), and to timely reveal deceases (including COVID-19). The authors proposed several biomarkers, which are recommended to use to monitor the water-resource system as a component of the urban ecosystem.
ABSTRACT
Continuity of key water, sanitation, and hygiene (WASH) infrastructure and WASH practices—for example, hand hygiene—are among several critical community preventive and mitigation measures to reduce transmission of infectious diseases, including COVID-19 and other respiratory diseases. WASH guidance for COVID-19 prevention may combine existing WASH standards and new COVID-19 guidance. Many existing WASH tools can also be modified for targeted WASH assessments during the COVID-19 pandemic. We partnered with local organizations to develop and deploy tools to assess WASH conditions and practices and subsequently implement, monitor, and evaluate WASH interventions to mitigate COVID-19 in low- and middle-income countries in Latin America and the Caribbean and Africa, focusing on healthcare, community institution, and household settings and hand hygiene specifically. Employing mixed-methods assessments, we observed gaps in access to hand hygiene materials specifically despite most of those settings having access to improved, often onsite, water supplies. Across countries, adherence to hand hygiene among healthcare providers was about twice as high after patient contact compared to before patient contact. Poor or non-existent management of handwashing stations and alcohol-based hand rub (ABHR) was common, especially in community institutions. Markets and points of entry (internal or external border crossings) represent congregation spaces, critical for COVID-19 mitigation, where globally-recognized WASH standards are needed. Development, evaluation, deployment, and refinement of new and existing standards can help ensure WASH aspects of community mitigation efforts that remain accessible and functional to enable inclusive preventive behaviors.
ABSTRACT
We developed and implemented a framework for examining how molecular assay sensitivity for a viral RNA genome target affects its utility for wastewater-based epidemiology. We applied this framework to digital droplet RT-PCR measurements of SARS-CoV-2 and Pepper Mild Mottle Virus genes in wastewater. Measurements were made using 10 replicate wells which allowed for high assay sensitivity, and therefore enabled detection of SARS-CoV-2 RNA even when COVID-19 incidence rates were relatively low (~10−5). We then used a computational downsampling approach to determine how using fewer replicate wells to measure the wastewater concentration reduced assay sensitivity and how the resultant reduction affected the ability to detect SARS-CoV-2 RNA at various COVID-19 incidence rates. When percent of positive droplets was between 0.024% and 0.5% (as was the case for SARS-CoV-2 genes during the Delta surge), measurements obtained with 3 or more wells were similar to those obtained using 10. When percent of positive droplets was less than 0.024% (as was the case prior to the Delta surge), then 6 or more wells were needed to obtain similar results as those obtained using 10 wells. When COVID-19 incidence rate is low (~ 10−5), as it was before the Delta surge and SARS-CoV-2 gene concentrations are <104 cp/g, using 6 wells will yield a detectable concentration 90% of the time. Overall, results support an adaptive approach where assay sensitivity is increased by running 6 or more wells during periods of low SARS-CoV-2 gene concentrations, and 3 or more wells during periods of high SARS-CoV-2 gene concentrations.
ABSTRACT
Shared water facilities are widespread in resource-poor settings within low- and middle-income countries. Since gathering water is essential, shared water sites may act as an important COVID-19 transmission pathway, despite stay-at-home recommendations. This analysis explores conditions under which shared water facility utilization may influence COVID-19 transmission. We developed two SEIR transmission models to explore COVID-19 dynamics. The first describes an urban setting, where multiple water sites are shared within a community, and the second describes a rural setting, where a single water site is shared among communities. We explored COVID-19 mitigation strategies including social distancing and adding additional water sites. Increased water site availability and social distancing independently attenuate attack rate and peak outbreak size through density reduction. In combination, these conditions result in interactive risk reductions. When water sharing intensity is high, risks are high regardless of the degree of social distancing. Even moderate reductions in water sharing can enhance the effectiveness of social distancing. In rural contexts, we observe similar but weaker effects. Enforced social distancing and density reduction at shared water sites can be an effective and relatively inexpensive mitigation effort to reduce the risk of COVID-19 transmission. Building additional water sites is more expensive but can increase the effectiveness of social distancing efforts at the water sites. As respiratory pathogen outbreaks—and potentially novel pandemics—will continue, infrastructure planning should consider the health benefits associated with respiratory transmission reduction when prioritizing investments.
ABSTRACT
Wastewater-based testing for SARS-CoV-2 is a novel tool for public health monitoring, but additional laboratory capacity is needed to provide routine monitoring at all locations where it has the potential to be useful. Few standardization practices for SARS-CoV-2 wastewater analysis currently exist, and quality assurance/quality control procedures may vary across laboratories. Alongside counterparts at many academic institutions, we built out a laboratory for routine monitoring of wastewater at the University of California, Berkeley. Here, we detail our group's establishment of a wastewater testing laboratory including standard operating procedures, laboratory buildout and workflow, and a quality assurance plan. We present a complete data analysis pipeline and quality scoring framework and discuss the data reporting process. We hope that this information will aid others at research institutions, public health departments, and wastewater agencies in developing programs to support wastewater monitoring for public health decision-making.
ABSTRACT
This paper reflects on the work that was done to establish a national wastewater pathogen surveillance system in New Zealand in response to the COVID-19 pandemic. After a short review of the wastewater literature, a timeline of SARS-CoV-2 is described to situate the work in a country that effectively eliminated COVID-19 from the community, but at the time of writing had a population that was more exposed than in other countries. The paper then turns to describe three broad categories of research needed to establish the COVID-19 wastewater surveillance system: monitoring, data analysis and ethics. Some of the work covers familiar ground for those trained in science, technology, engineering and mathematics, such as the spatial location and temporal frequency of field sampling. Other work sits more comfortably with those trained in the humanities and social science, such as population mobility and the ethics of surveillance. The message that comes from our experience is the need to work together, which takes courage, empathy and patience as we learn to accept each other's epistemological foundations and modus operandi.
ABSTRACT
There are a range of spatial scales addressed in the papers, from the individual building scale to the cargo ship (Coxon et al., 'Exploring opportunities for sewage testing on cargo ships as a tool to screen seafarers for COVID-19'), subcatchment to sewershed (Nicoll et al., 'Neighbourhood-scale wastewater-based epidemiology for COVID-19'), and city to national (Gilpin et al., A pilot study of wastewater monitoring for SARS-CoV-2 in New Zealand' and Trowsdale et al., 'Establishing New Zealand's national pathogen surveillance system using wastewater-based epidemiology');and all the papers make use of the international literature to provide context for what is a global pandemic. Marrying such information with environmental water samples collected on a daily or weekly basis is problematic. Repurposing data also raises important ethical questions of ownership, confidentiality and responsibility that need to be asked to ensure what we scientists do is both good and right (Price and Trowsdale, 'The ethics of wastewater surveillance for public health').
ABSTRACT
The COVID-19 pandemic has fuelled interest in the use of wastewater analysis for public health surveillance. Hydrologists, engineers, environmental scientists, microbiologists, public health experts and those in other disciplines have been tasked with the implementation of national-scale surveillance and the resultant data have been used for decision making at the highest levels of government. The widespread surveillance of communities is not without its concerns, however. This paper explores the ethics of surveillance drawing on the literature and our experiences with wastewater analysis. Consent is not typically required for wastewater surveillance, which can exacerbate perceptions of risk and undermine public trust. Seemingly innocuous communication of surveillance data can stigmatise communities and perpetuate inequities. There are tensions between the desire for the rapid delivery of information and the time needed to build confidence in surveillance data. There are also limitations and uncertainties in the science of wastewater surveillance, and these add to the pressures of communication for and with decision makers. Media representations can be problematic and perpetuate social stigma. On a positive note, the transdisciplinary nature of wastewater surveillance presents an opportunity to work across and beyond traditional disciplinary boundaries to address the ethics of surveillance, which, we expect, will be especially important as wastewater surveillance becomes further mainstreamed, particularly under the auspices of surveillance capitalism.
ABSTRACT
Auckland is New Zealand's largest city and is the main international entry point to New Zealand, with most of the nation's Managed Isolation and Quarantine Facilities. Consequently, it is the place most likely for a COVID-19 outbreak to occur and, accordingly, has been the focus of efforts to monitor SARS-CoV-2 via wastewater-based epidemiology. Historically, wastewater-based epidemiology has mainly been applied at the catchment or sewershed scale, with samples collected at wastewater treatment plants. COVID-19 has necessitated a re-evaluation of this broad-scale approach to wastewaterbased epidemiology in New Zealand, where there is a need for more detailed information to better target the public health response. Using Auckland as a case study, this paper assesses the spatial and temporal extent of the city's wastewater network to inform the selection of strategic neighbourhoodscale sampling sites for wastewater-based epidemiology. Sample site selection criteria included topology and connectivity of the sewer network, the capacity to record sewer flow, limited rain infiltration, resident population, and accessibility. Six sites were identified that provide an immediate opportunity for neighbourhood-scale monitoring. Reflecting on the analysis required for selecting appropriate monitoring locations, the paper moves to critically discuss the key unknowns and research needs associated with conducting neighbourhoodscale wastewater-based epidemiology. Population mobility poses challenges for estimating population size and for capturing a positive SARS-CoV-2 signal in wastewater at this scale. There is a need to determine the full spectrum of residence times within the sewer network to design representative sampling and the implications of disregarding residence times in the current sampling regimes are poorly understood. Hydraulic models require refinement to accurately account for variable residence times and topological features in the network (e.g., holding tanks and pumping stations). Addressing these challenges is urgent and ongoing to realise the benefits of neighbourhood-scale wastewater-based epidemiology in response to COVID-19 and beyond.
ABSTRACT
Surveillance of municipal wastewater for RNA of SARS-CoV-2, the causative agent of coronavirus disease (COVID-19), is well documented around the world. However, unlike most countries where wastewater surveillance was initially employed during 2020, New Zealand was in the fortunate position of having very few COVID-19 cases, generally confined to Managed Isolation and Quarantine facilities. As such, the prevalence of SARS-CoV-2 RNA in wastewater was likely much lower than seen in other countries. A nine-week pilot study was undertaken to assess the feasibility of detecting SARSCoV-2 RNA in wastewater in New Zealand. Wastewater from 18 catchments across New Zealand was monitored, including six that contained Managed Isolation and Quarantine facilities. Testing both in regions known to have COVID-19 cases and regions where detection was not expected (catchments not containing Managed Isolation and Quarantine facilities) allowed the sensitivity and specificity of detection methods to be assessed. SARS-CoV-2 RNA was detected in seven out of the nine weeks of this study in the Auckland South Western Interceptor catchment, which contained a dedicated isolation facility to which confirmed cases from Auckland, Hamilton and Rotorua were transferred. In weeks two and three of sampling, SARS-CoV-2 RNA was detected in the Christchurch catchment. This coincided with up to 14 COVID-19 cases likely to be shedding high levels of virus (PCR Cq value < 20) in the Managed Isolation and Quarantine facilities. Samples from the seven other weeks were negative despite up to 35 infected cases present at any one time. However, on any of these test dates eight cases or fewer had a PCR Cq value < 30 and were within 10 days of symptom onset or positive PCR test date. Sample inhibition and non-specificity were not observed to be issues. The results of this pilot study underpinned recommendations that wastewater monitoring for SARS-CoV-2 RNA be incorporated as a surveillance tool in New Zealand's COVID-19 response.
ABSTRACT
Stringent border controls and surveillance measures have been an essential part of the New Zealand Government's response to the coronavirus disease 2019 (COVID-19) pandemic, particularly its elimination strategy, which requires all infected individuals arriving at the border to be identified and isolated to prevent incursions and community transmission. The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus that causes COVID-19 is shed in the faeces and other bodily secretions of infected people, and municipal wastewater-based surveillance for SARS-CoV-2 has been extensively utilised at both localised and community scales. This review article explores whether testing the sewage from cargo ships arriving at the New Zealand maritime border could be used in a similar way, serving as a screening mechanism to help protect the border. Whilst considerable knowledge gaps remain regarding the prevalence, onset and kinetics of faecal shedding of SARS-CoV-2, the available data suggest approximately half of infected individuals shed detectable levels of RNA in their stool, with the onset of shedding starting anywhere between the first and fifth week of illness. Engineering and health and safety considerations are also discussed. We conclude that testing sewage from ships is unlikely to detect cases of COVID-19 amongst crew with the reliability required by an elimination strategy, particularly given individual-level nasopharyngeal testing is readily administered to the relatively small crew aboard these vessels. However, other opportunities for testing sewage from ships for SARS-CoV-2 may exist, such as when border settings are relaxed and/or individual-level testing is not practical or warranted (e.g., cruise ships), or in surveillance for other pathogens.
ABSTRACT
Changes in the atmospheric electricity characteristics (AECs) during the spring of 2020 in the urban, suburban, and very low human impact areas (Irkutsk, Irkutsk oblast;Voeikovo, Leningrad oblast;Tiksi, Republic of Sakha) are considered. Based on the AEC data, a theoretical assessment of the change in aerosol concentrations at these sites was carried out. Apparently, the decline in economic activity associated with the measures to prevent the expansion of COVID-19 significantly decreased the concentration of airborne particles in cities and suburban regions.
ABSTRACT
Changes in the atmospheric composition during different periods of 2020 in Moscow which were associated with the COVID-19 pandemic preventing measures as well as corresponding pollutant emission reduction, are investigated. Surface concentrations of nitrogen dioxide (NO2), carbon monoxide (CO), ozone (O3), aerosol fraction (PM10), and meteorological parameters during different periods of 2020 were compared with similar data for the previous five years. The analysis of ground-based measurements, as well as of high-resolution satellite distributions of CO and NO2 indicated that the concentration of major pollutants and its spatial distribution in the Moscow region were significantly affected by both restrictive measures and abnormal meteorological conditions in 2020.
ABSTRACT
The results of numerical modeling of air pollution using CHIMERE and COSMO-ART chemical transport models are presented. The modeling was performed according to the scenarios of the 50–60% reduction of emissions from anthropogenic sources in the Moscow region during the period of March–July 2020. Scenario calculations of pollutant concentrations were compared with baseline simulations using regionally adapted inventory of anthropogenic pollutant emissions to the atmosphere. The most significant decrease in the concentrations of NO2 and CO was reproduced by the models when emissions from two sectoral sources (vehicles and nonindustrial plants) were reduced. The PM10 drop was mostly influenced by the reduction of emissions from industrial combustion. With the total reduction of emissions from anthropogenic sources as compared to the baseline calculations, the pollutant concentration decreased by 44–54% for NO2, by 38–44% for CO, and by 26–39% for PM10. This generally coincides with the quantitative estimates of the pollution level drop obtained by other authors. The greatest effect of reducing pollutant emissions into the atmosphere was found during the episodes of adverse weather conditions for air purification, when the simulated and observed pollution level increases by 3–5 times as compared to the conditions of intense pollutant dispersion.