Detection, fate and inactivation of pathogenic norovirus employing settlement and UV treatment in wastewater treatment facilities

Advancing Public Health Surveillance: Integrating Modeling and GIS in the Wastewater-Based Epidemiology of Viruses, a Narrative Review

This review article will present a comprehensive examination of the use of modeling, spatial analysis, and geographic information systems (GIS) in the surveillance of viruses in wastewater. With the advent of global health challenges like the COVID-19 pandemic, wastewater surveillance has emerged as a crucial tool for the early detection and management of viral outbreaks. This review will explore the application of various modeling techniques that enable the prediction and understanding of virus concentrations and spread patterns in wastewater systems. It highlights the role of spatial analysis in mapping the geographic distribution of viral loads, providing insights into the dynamics of virus transmission within communities. The integration of GIS in wastewater surveillance will be explored, emphasizing the utility of such systems in visualizing data, enhancing sampling site selection, and ensuring equitable monitoring across diverse populations. The review will also discuss the innovative combination of GIS with remote sensing data and predictive modeling, offering a multi-faceted approach to understand virus spread. Challenges such as data quality, privacy concerns, and the necessity for interdisciplinary collaboration will be addressed. This review concludes by underscoring the transformative potential of these analytical tools in public health, advocating for continued research and innovation to strengthen preparedness and response strategies for future viral threats. This article aims to provide a foundational understanding for researchers and public health officials, fostering advancements in the field of wastewater-based epidemiology.

Viruses in Wastewater-A Concern for Public Health and the Environment

Wastewater monitoring provides essential information about water quality and the degree of contamination. Monitoring these waters helps identify and manage risks to public health, prevent the spread of disease, and protect the environment. Standardizing the appropriate and most accurate methods for the isolation and identification of viruses in wastewater is necessary. This review aims to present the major classes of viruses in wastewater, as well as the methods of concentration, isolation, and identification of viruses in wastewater to assess public health risks and implement corrective measures to prevent and control viral infections. Last but not least, we propose to evaluate the current strategies in wastewater treatment as well as new alternative methods of water disinfection.

Research Progress on Biological Accumulation, Detection and Inactivation Technologies of Norovirus in Oysters

Noroviruses (NoVs) are major foodborne pathogens that cause acute gastroenteritis. Oysters are significant carriers of this pathogen, and disease transmission from the consumption of NoVs-infected oysters occurs worldwide. The review discusses the mechanism of NoVs bioaccumulation in oysters, particularly the binding of histo-blood group antigen-like (HBGA-like) molecules to NoVs in oysters. The review explores the factors that influence NoVs bioaccumulation in oysters, including temperature, precipitation and water contamination. The review also discusses the detection methods of NoVs in live oysters and analyzes the inactivation effects of high hydrostatic pressure, irradiation treatment and plasma treatment on NoVs. These non-thermal processing treatments can remove NoVs efficiently while retaining the original flavor of oysters. However, further research is needed to reduce the cost of these technologies to achieve large-scale commercial applications. The review aims to provide novel insights to reduce the bioaccumulation of NoVs in oysters and serve as a reference for the development of new, rapid and effective methods for detecting and inactivating NoVs in live oysters.

Current decontamination challenges and potentially complementary solutions to safeguard the vulnerable seafood industry from recalcitrant human norovirus in live shellfish: Quo Vadis?

Safeguarding the seafood industry is important given its contribution to supporting our growing global population. However, shellfish are filter feeders that bioaccumulate microbial contaminants in their tissue from wastewater discharged into the same coastal growing environments leading to significant human disease outbreaks unless appropriately mitigated. Removal or inactivation of enteric viruses is very challenging particularly as human norovirus (hNoV) binds to specific histo-blood ligands in live oyster tissue that are consumed raw or lightly cooked. The regulatory framework that sets out use of clean seawater and UV disinfection is appropriate for bacterial decontamination at the post-harvest land-based depuration (cleaning) stage. However, additional non-thermal technologies are required to eliminate hNoV in live shellfish (particularly oysters) where published genomic studies report that low-pressure UV has limited effectiveness in inactivating hNoV. The use of the standard genomic detection method (ISO 15, 216-1:2017) is not appropriate for assessing the loss of infectious hNoV in treated live shellfish. The use of surrogate viral infectivity methods appear to offer some insight into the loss of hNoV infectiousness in live shellfish during decontamination. This paper reviews the use of existing and potentially other combinational treatment approaches to enhance the removal or inactivation of enteric viruses in live shellfish. The use of alternative and complementary novel diagnostic approaches to discern viable hNoV are discussed. The effectiveness and virological safety of new affordable hNoV intervention(s) require testing and validating at commercial shellfish production in conjunction with laboratory-based research. Appropriate risk management planning should encompass key stakeholders including local government and the wastewater industry. Gaining a mechanistic understanding of the relationship between hNoV response at molecular and structural levels in individually treated oysters as a unit will inform predictive modeling and appropriate treatment technologies. Global warming of coastal growing environments may introduce additional contaminant challenges (such as invasive species); thus, underscoring need to develop real-time ecosystem monitoring of growing environments to alert shellfish producers to appropriately mitigate these threats.

Bacteriophage-based biocontrol technology to enhance the efficiency of wastewater treatment and reduce targeted bacterial biofilms

Wastewater treatment is an essential process for public health and a sustainable ecosystem. Inadequate wastewater treatment can lead to the release of organic and inorganic pollutants and pathogenic bacteria into the receiving waters which could be further utilized for recreation purposes. The interaction between bacteriophage and bacteria in a wastewater treatment plant plays a major role in maintaining the treatment process. Phage therapy has been proposed as an alternative to conventional treatment methods as bacteriophages can be used on specific targets and leave useful bacteria unharmed. The bacterial species, which are responsible for bulking, foaming, and biofilm formation in a wastewater treatment plant (WWTP) have been identified and their respective phages are isolated to control their growth. Phages with lytic life cycles are preferred to lysogenic. Lytic phages can kill the specific target as they lyse the cell, infect most of the hosts, and have an immediate effect on controlling problems caused by bacteria in a WWTP. The bacteriophages such as T7, SPI1, GTE7, PhaxI, MAG1, MAG2, ϕPh_Se01, ϕPh_Se02, and Bxb1 have been investigated for the removal of bacterial biofilms from wastewater. Novel experimental setups have improved the efficiency of phage therapy in small-scale and pilot-scale experiments. Much more in-depth knowledge of the microbial community and their interaction would help promote the usage of phage therapy in large-scale wastewater treatments. This paper has covered the recent advancements in phage therapy as an effective biocontrol of pathogenic bacteria in the wastewater treatment process and has looked at certain shortcomings that have to be improved.

Digital transformation of peatland eco-innovations ('Paludiculture'): Enabling a paradigm shift towards the real-time sustainable production of 'green-friendly' products and services

The world is heading in the wrong direction on carbon emissions where we are not on track to limit global warming to 1.5 °C; Ireland is among the countries where overall emissions have continued to rise. The development of wettable peatland products and services (termed 'Paludiculture') present significant opportunities for enabling a transition away from peat-harvesting (fossil fuels) to developing 'green' eco-innovations. However, this must be balanced with sustainable carbon sequestration and environmental protection. This complex transition from 'brown to green' must be met in real time by enabling digital technologies across the full value chain. This will potentially necessitate creation of new green-business models with the potential to support disruptive innovation. This timely paper describes digital transformation of paludiculture-based eco-innovation that will potentially lead to a paradigm shift towards using smart digital technologies to address efficiency of products and services along with future-proofing for climate change. Digital transform of paludiculture also aligns with the 'Industry 5.0 - a human-centric solution'. However, companies supporting peatland innovation may lack necessary standards, data-sharing or capabilities that can also affect viable business model propositions that can jeopardize economic, political and social sustainability. Digital solutions may reduce costs, increase productivity, improve produce develop, and achieve faster time to market for paludiculture. Digitisation also enables information systems to be open, interoperable, and user-friendly. This constitutes the first study to describe the digital transformation of paludiculture, both vertically and horizontally, in order to inform sustainability that includes process automation via AI, machine learning, IoT-Cloud informed sensors and robotics, virtual and augmented reality, and blockchain for cyber-physical systems. Thus, the aim of this paper is to describe the applicability of digital transformation to actualize the benefits and opportunities of paludiculture activities and enterprises in the Irish midlands with a global orientation.

Illuminating Human Norovirus: A Perspective on Disinfection of Water and Surfaces Using UVC, Norovirus Model Organisms, and Radiation Safety Considerations

Human noroviruses (HuNoVs) are a major cause of gastroenteritis and are associated with high morbidity because of their ability to survive in the environment and small inoculum size required for infection. Norovirus is transmitted through water, food, high touch-surfaces, and human-to-human contact. Ultraviolet Subtype C (UVC) light-emitting diodes (LEDs) can disrupt the norovirus transmission chain for water, food, and surfaces. Here, we illuminate considerations to be adhered to when picking norovirus surrogates for disinfection studies and shine light on effective use of UVC for norovirus infection control in water and air and validation for such systems and explore the blind spot of radiation safety considerations when using UVC disinfection strategies. This perspective also discusses the promise of UVC for norovirus mitigation to save and ease life.

The novel SARS-CoV-2 pandemic: Possible environmental transmission, detection, persistence and fate during wastewater and water treatment

The contagious SARS-CoV-2 virus, responsible for COVID-19 disease, has infected over 27 million people across the globe within a few months. While literature on SARS-CoV-2 indicates that its transmission may occur predominantly via aerosolization of virus-laden droplets, the possibility of alternate routes of transmission and/or reinfection via the environment requires considerable scientific attention. This review aims to collate information on possible transmission routes of this virus, to ascertain its fate in the environment. Concomitant with the presence of SARS-CoV-2 viral RNA in faeces and saliva of infected patients, studies also indicated its occurrence in raw wastewater, primary sludge and river water. Therefore sewerage system could be a possible route of virus outbreak, a possible tool to assess viral community spread and future surveillance technique. Hence, this review looked into detection, occurrence and fate of SARS-CoV-2 during primary, secondary, and tertiary wastewater and water treatment processes based on published literature on SARS-CoV and other enveloped viruses. The review also highlights the need for focused research on occurrence and fate of SARS-CoV-2 in various environmental matrices. Utilization of this information in environmental transmission models developed for other enveloped and enteric viruses can facilitate risk assessment studies. Preliminary research efforts with SARS-CoV-2 and established scientific reports on other coronaviruses indicate that the threat of virus transmission from the aquatic environment may be currently non-existent. However, the presence of viral RNA in wastewater provides an early warning that highlights the need for effective sewage treatment to prevent a future outbreak of SARS-CoV-2.

SARS-CoV-2 in environmental perspective: Occurrence, persistence, surveillance, inactivation and challenges

The unprecedented global spread of the severe acute respiratory syndrome (SARS) caused by SARS-CoV-2 is depicting the distressing pandemic consequence on human health, economy as well as ecosystem services. So far novel coronavirus (CoV) outbreaks were associated with SARS-CoV-2 (2019), middle east respiratory syndrome coronavirus (MERS-CoV, 2012), and SARS-CoV-1 (2003) events. CoV relates to the enveloped family of Betacoronavirus (βCoV) with positive-sense single-stranded RNA (+ssRNA). Knowing well the persistence, transmission, and spread of SARS-CoV-2 through proximity, the faecal-oral route is now emerging as a major environmental concern to community transmission. The replication and persistence of CoV in the gastrointestinal (GI) tract and shedding through stools is indicating a potential transmission route to the environment settings. Despite of the evidence, based on fewer reports on SARS-CoV-2 occurrence and persistence in wastewater/sewage/water, the transmission of the infective virus to the community is yet to be established. In this realm, this communication attempted to review the possible influx route of the enteric enveloped viral transmission in the environmental settings with reference to its occurrence, persistence, detection, and inactivation based on the published literature so far. The possibilities of airborne transmission through enteric virus-laden aerosols, environmental factors that may influence the viral transmission, and disinfection methods (conventional and emerging) as well as the inactivation mechanism with reference to the enveloped virus were reviewed. The need for wastewater epidemiology (WBE) studies for surveillance as well as for early warning signal was elaborated. This communication will provide a basis to understand the SARS-CoV-2 as well as other viruses in the context of the environmental engineering perspective to design effective strategies to counter the enteric virus transmission and also serves as a working paper for researchers, policy makers and regulators.

Occurrence, fates and potential treatment approaches for removal of viruses from wastewater: A review with emphasis on SARS-CoV-2

The world is combating the emergence of Coronavirus disease 2019 (COVID-19) caused by novel coronavirus; severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Further, due to the presence of SARS-CoV-2 in sewage and stool samples, its transmission through water routes cannot be neglected. Thus, the efficient treatment of wastewater is a matter of utmost importance. The conventional wastewater treatment processes demonstrate a wide variability in absolute removal of viruses from wastewater, thereby posing a severe threat to human health and environment. The fate of SARS-CoV-2 in the wastewater treatment plants and its removal during various treatment stages remains unexplored and demands immediate attention; particularly, where treated effluent is utilised as reclaimed water. Consequently, understanding the prevalence of pathogenic viruses in untreated/treated waters and their removal techniques has become the topical issue of the scientific community. The key objective of the present study is to provide an insight into the distribution of viruses in wastewater, as well as the prevalence of SARS-CoV-2, and its possible transmission by the faecal-oral route. The review also gives a detailed account of the major waterborne and non-waterborne viruses, and environmental factors governing the survival of viruses. Furthermore, a comprehensive description of the potential methods (physical, chemical, and biological) for removal of viruses from wastewater has been presented. The present study also intends to analyse the research trends in microalgae-mediated virus removal and, inactivation. The review also addresses the UN SDG 'Clean Water and Sanitation' as it is aimed at providing pathogenically safe water for recycling purposes.

Concentration methods for the quantification of coronavirus and other potentially pandemic enveloped virus from wastewater

As the novel SARS-CoV-2 was detected in faeces, environmental researchers have been using centrifugal ultrafiltration, polyethylene glycol precipitation and aluminium hydroxide flocculation to describe its presence in wastewater samples. High recoveries (up to 65%) are described with electronegative filtration when using surrogate viruses, but few literature reports recovery efficiencies using accurate quantification of enveloped viruses. Considering that every single virus will have a different behaviour during viral concentration, it is recommended to use an enveloped virus, and if possible, a betacoronaviruses as murine hepatitis virus, as a surrogate. In this review, we show new data from a newly available technology that provides a quick ultrafiltration protocol for SARS-CoV-2. Wastewater surveillance is an efficient system for the evaluation of the relative prevalence of SARS-CoV-2 infections in a community, and there is the need of using reliable concentration methods for an accurate and sensitive quantification of the virus in water.

Challenges and solutions for addressing critical shortage of supply chain for personal and protective equipment (PPE) arising from Coronavirus disease (COVID19) pandemic - Case study from the Republic of Ireland

Coronavirus (COVID-19) is highly infectious agent that causes fatal respiratory illnesses, which is of great global public health concern. Currently, there is no effective vaccine for tackling this COVID19 pandemic where disease countermeasures rely upon preventing or slowing person-to-person transmission. Specifically, there is increasing efforts to prevent or reduce transmission to front-line healthcare workers (HCW). However, there is growing international concern regarding the shortage in supply chain of critical one-time-use personal and protective equipment (PPE). PPE are heat sensitive and are not, by their manufacturer's design, intended for reprocessing. Most conventional sterilization technologies used in hospitals, or in terminal medical device sterilization providers, cannot effectively reprocess PPE due to the nature and severity of sterilization modalities. Contingency planning for PPE stock shortage is important. Solutions in the Republic of Ireland include use of smart communication channels to improve supply chain, bespoke production of PPE to meets gaps, along with least preferred option, use of sterilization or high-level disinfection for PPE reprocessing. Reprocessing PPE must consider material composition, functionality post treatment, along with appropriate disinfection. Following original manufacturer of PPE and regulatory guidance is important. Technologies deployed in the US, and for deployment in the Republic of Ireland, are eco-friendly, namely vaporised hydrogen peroxide (VH2O2), such as for filtering facepiece respirators and UV irradiation and High-level liquid disinfection (Actichlor+) is also been pursed in Ireland. Safeguarding supply chain of PPE will sustain vital healthcare provision and will help reduce mortality.

Novel use of peatlands as future locations for the sustainable intensification of freshwater aquaculture production - A case study from the Republic of Ireland

There has been an increasing interest in enhancing freshwater aquaculture processes without hindering the progress of the Water Framework Directive. This constitutes the first study to describe a new concept in integrated multitrophic aquaculture (IMTA) that uses cutaway peatlands (bogs) to farm rainbow trout and Eurasian perch with associated organic status that is powered by wind energy and utilizes algae and duckweed to treat rearing water. Approximately 5% of Ireland comprises bogs that support natural ecosystems where there is a pressing need to develop alternative innovation to that of burning peat in order to reduce Ireland's carbon emissions. Specifically, this study evaluates water quality from this new IMTA where intake and terminal holding tank samples were evaluated from May to August 2019. Physicochemical parameters (temperature, pH, nitrogen, phosphorus, oxygen, suspended solids, hardness and alkalinity), and ecotoxicological bioassays (Pseudokirchneriella subcapitata and Daphnia pulex), were used to investigate the potential effects that introducing aquaculture processes may have on peatlands. Nitrite (P < 0.001), nitrate (P = 0.016), and chemical oxygen demand (P = 0.011), were the only physicochemical parameters that differed significantly between the intake and holding tank water indicating that water quality for the most part remained unchanged. Low levels of toxicity were observed between the bioassays suggested the introduction of the processes into the bog were unlikely to cause adverse effects on the ecosystem and the organisms therein. Observations were similar to or lower than those reported previously by other researchers for intensive flow-through aquaculture processes that discharge to receiving water. Findings from this study support the use of peatlands as future locations for integrated aquaculture processes.

Inactivation and Loss of Infectivity of Enterovirus 70 by Solar Irradiation

Enterovirus 70 (EV70) is an emerging viral pathogen that remains viable in final treated effluent. Solar irradiation is, therefore, explored as a low-cost natural disinfection strategy to mitigate potential concerns. EV70 was exposed to simulated sunlight for 24 h at a fluence rate of 28.67 J/cm2/h in three different water matrices, namely, phosphate-buffered saline (PBS), treated wastewater effluent, and chlorinated effluent. In the presence of sunlight, EV70 decreased in infectivity by 1.7 log, 1.0 log, and 1.3 log in PBS, effluent, and chlorinated effluent, respectively. Irradiated EV70 was further introduced to host cell lines and was unable to infect the cell lines. In contrast, EV70 in dark microcosms replicated to titers 13.5, 3.3, and 4.2 times the initial inoculum. The reduction in EV70 infectivity was accompanied by a reduction in viral binding capacity to Vero cells. In addition, genome sequencing analysis revealed five nonsynonymous nucleotide substitutions in irradiated viruses after 10 days of infection in Vero cells, resulting in amino acid substitutions: Lys14Glu in the VP4 protein, Ala201Val in VP2, Gly71Ser in VP3, Glu50Gln in VP1, and Ile47Leu in 3Cpro. Overall, solar irradiation resulted in EV70 inactivation and an inhibition of viral activity in all parameters studied.

DairyWater: striving for sustainability within the dairy processing industry in the Republic of Ireland

This Review describes the objectives and methodology of the DairyWater project as it aims to aid the Irish dairy processing industry in achieving sustainability as it expands. With the abolition of European milk quotas in March 2015, the Republic of Ireland saw a surge in milk production. The DairyWater project was established in anticipation of this expansion of the Irish dairy sector in order to develop innovative solutions for the efficient management of water consumption, wastewater treatment and the resulting energy use within the country's dairy processing industry. Therefore, the project can be divided into three main thematic areas: dairy wastewater treatment technologies and microbial analysis, water re-use and rainwater harvesting and environmental assessment. In order to ensure the project remains as relevant as possible to the industry, a project advisory board containing key industry stakeholders has been established. To date, a number of large scale studies, using data obtained directly from the Irish dairy industry, have been performed. Additionally, pilot-scale wastewater treatment (intermittently aerated sequencing batch reactor) and tertiary treatment (flow-through pulsed ultraviolet system) technologies have been demonstrated within the project. Further details on selected aspects of the project are discussed in greater detail in the subsequent cluster of research communications.

Critical Review on the Public Health Impact of Norovirus Contamination in Shellfish and the Environment: A UK Perspective

We review the risk of norovirus (NoV) infection to the human population from consumption of contaminated shellfish. From a UK perspective, risk is apportioned for different vectors of NoV infection within the population. NoV spreads mainly by person-to-person contact or via unsanitary food handling. NoV also enters the coastal zone via wastewater discharges resulting in contamination of shellfish waters. Typically, NoV persists in the marine environment for several days, with its presence strongly linked to human population density, wastewater discharge rate, and efficacy of wastewater treatment. Shellfish bioaccumulate NoV and current post-harvest depuration is inefficient in its removal. While NoV can be inactivated by cooking (e.g. mussels), consumption of contaminated raw shellfish (e.g. oysters) represents a risk to human health. Consumption of contaminated food accounts for 3-11% of NoV cases in the UK (~74,000 cases/year), of which 16% are attributable to oyster consumption (11,800 cases/year). However, environmental and human factors influencing NoV infectivity remain poorly understood. Lack of standard methods for accurate quantification of infective and non-infective (damaged) NoV particles represent a major barrier, hampering identification of an appropriate lower NoV contamination limit for shellfish. Future management strategies may include shellfish quality assessment (at point of harvest or at point of supply) or harvesting controls. However, poor understanding of NoV inactivation in shellfish and the environment currently limits accurate apportionment and risk assessment for NoV and hence the identification of appropriate shellfish or environmental quality standards.

Environmental indicators for human norovirus outbreaks

Norovirus is the most common cause of outbreaks of non-bacterial gastroenteritis in human. While the winter seasonality of norovirus outbreaks has been widely reported, the association between norovirus outbreak epidemics and environmental factors remains not fully understood. This literature review is intended to improve understanding of environmental factors governing norovirus outbreaks and how the factors affect norovirus transmission. To that end, a large number of studies (67) from countries around the world were critically reviewed and discussed. Results of the literature review show that temperature, humidity, and rainfall are the most important environmental variables governing the norovirus epidemic cycle. It was found that low temperature between -6.6 and 20 °C, relative humidity between 10 and 66 %, and rainfall from 1 day to 3 months before an outbreak are effective ranges of the environmental factors, which favor the prevalence of norovirus. Some other environmental factors might have an association with the cycle of norovirus epidemics. However, further investigations are needed to understand effects of the other factors on norovirus incidence. The findings of this literature review improve our understanding of the relationship between norovirus outbreaks and environmental factors and provide the direction for future research on norovirus outbreaks.