SARS-CoV-2 RNA detection of hospital isolation wards hygiene monitoring during the Coronavirus Disease 2019 outbreak in a Chinese hospital

A wastewater-based epidemiology tool for COVID-19 surveillance in Portugal

The presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in wastewater produced interest in its use for sentinel surveillance at a community level and as a complementary approach to syndromic surveillance. With this work, we set the foundations for wastewater-based epidemiology (WBE) in Portugal by monitoring the trends of SARS-CoV-2 RNA circulation in the community, on a nationwide perspective during different epidemiological phases of the pandemic. The Charité assays (E_Sarbecco, RdRP, and N_Sarbecco) were applied to monitor, over 32-weeks (April to December 2020), the dynamics of SARS-CoV-2 RNA at the inlet of five wastewater treatment plants (WWTP), which together serve more than two million people in Portugal. Raw wastewater from three Coronavirus disease 2019 (COVID-19) reference hospitals was also analyzed during this period. In total, more than 600 samples were tested. For the first weeks, detection of SARS-CoV-2 RNA was sporadic, with concentrations varying from 103 to 105 genome copies per liter (GC/L). Prevalence of SARS-CoV-2 RNA increased steeply by the end of May into late June, mainly in Lisboa e Vale do Tejo region (LVT), during the reopening phase. After the summer, with the reopening of schools in mid-September and return to partial face-to-face work, a pronounced increase of SARS-CoV-2 RNA in wastewater was detected. In the LVT area, SARS-CoV-2 RNA load agreed with reported trends in hotspots of infection. Synchrony between trends of SARS-CoV-2 RNA in raw wastewater and daily new COVID-19 cases highlights the value of WBE as a surveillance tool, particularly after the phasing out of the epidemiological curve and when hotspots of disease re-emerge in the population which might be difficult to spot based solely on syndromic surveillance and contact tracing. This is the first study crossing several epidemiological stages highlighting the long-term use of WBE for SARS-CoV-2.

SARS-CoV-2 Environmental contamination in hospital rooms is uncommon using viral culture techniques

We assessed environmental contamination of inpatient rooms housing COVID-19 patients in a dedicated COVID-19 unit. Contamination with SARS-CoV-2 was found on 5.5% (19/347) of surfaces via RT-PCR and 0.3% (1/347) of surfaces via cell culture. Environmental contamination is uncommon in hospitals rooms; RNA presence is not a specific indicator of infectious virus.

Assessment method for new sustainability indicators providing pandemic resilience for residential buildings

The method presented in this paper aims to support the sustainability assessment methods of residential buildings under pandemic conditions. The main purpose of the study is to review existing criteria of the well-known assessment tools and then to suggest a set of assessment measures for the emerging pandemic-resilient indicators. Current sustainability assessment methodologies mostly focus on the conventional sustainability pillars (Environmental, Social, Economic), whereas the proposed emerging sustainability assessment indicators include changes in sustainability requirements brought by the current pandemic. Firstly, a set of indicators with possible measures was identified; then, we reviewed several existing green building certification systems to identify their gaps and developed a foundation for each indicator. Finally, several round table discussions involving various stakeholders (e.g., engineers, designers, health care experts, academics) were conducted to consolidate the identified measures. The findings of the present study indicate that certain pandemic-resilient indicators are not fully addressed by existing assessment tools, pointing out the importance of the development of new measures to make them more suitable to use under pandemic conditions. Thus, the present study contributes to the building assessment methods by proposing a set of emerging assessment indicators with measures, which can be used by various professionals that would contribute to more sustainable buildings in upcoming pandemics.•A 5-point scale was used to assess the indicators, and various stakeholders in a previous study identified their weights.•The methodology introduces new pandemic-related indicators into the conventional sustainability concept.•The assessment measures are rapid and economically efficient to apply for any residential building.

Field study of the indoor environments for preventing the spread of the SARS-CoV-2 in Seoul

Despite the prolonged global spread of COVID-19, few studies have investigated the environmental influence on the spread of SARS-CoV-2 RNA with a metropolitan scale, particularly the detection of SARS-CoV-2 after disinfection at multi-use facilities. Between February 2020 and January 2021, 1,769 indoor air samples and object surfaces were tested at 231 multi-use facilities where confirmed cases were known to have occurred in Seoul, to determine whether SARS-CoV-2 RNA could be detected even after disinfection. Samples were collected by air scanner and swab pipette and detected by real-time RT-PCR. As a result, 10 (0.56%) positive samples were detected despite disinfection. The common environmental features of all 10 were surfaces that contained moisture and windowless buildings. With the aim of preventing the spread of COVID-19, from January to February 2021, we next conducted 643 preemptive tests before the outbreak of infections at 22 multi-use facilities where cluster infections were frequent. From these preemptive inspections, we obtained five (0.78%) positive results from two facilities, which enabled us to disinfect the buildings and give all the users a COVID-19 test. Based on the study purpose of finding and investigating cases of positive detection even after disinfection in the field through long-term environmental detection in a large city, our preemptive investigation results helped to prevent the spread of infectious diseases by confirming the potential existence of an asymptomatic patient.

Design characteristics on the indoor and outdoor air environments of the COVID-19 emergency hospital

According to the discussion of the design method and operational effect for Wuhan Huoshenshan Hospital, this paper summarized the design control points of indoor and outdoor environment of COVID-19 emergency hospital. Based on the design of Wuhan Huoshenshan Hospital, this paper analyzed and discussed the site design, building layout, three-zones and two-passages, the design scheme of the ventilation and air conditioning system for negative pressure ward and negative pressure isolation ward, air distribution, as well as some other key designs for COVID-19 emergency hospital. The design points were summarized and refined. The design methods and technology requirements of the COVID-19 emergency hospital were provided in this study, such as ventilation and air conditioning system setting, ventilation quantity of wards, pressure gradient control measures among different areas, upper and lower air distribution, filter setting mode and distance of air inlet and outlet, which could benefit to provide references for the design of similar projects in the future.

First evidence of SARS-CoV-2 genome detection in zebra mussel (Dreissena polymorpha)

The uses of bivalve molluscs in environmental biomonitoring have recently gained momentum due to their ability to indicate and concentrate human pathogenic microorganisms. In the context of the health crisis caused by the COVID-19 epidemic, the objective of this study was to determine if the SARS-CoV-2 ribonucleic acid genome can be detected in zebra mussels (Dreissena polymorpha) exposed to raw and treated urban wastewaters from two separate plants to support its interest as bioindicator of the SARS-CoV-2 genome contamination in water. The zebra mussels were exposed to treated wastewater through caging at the outlet of two plants located in France, as well as to raw wastewater in controlled conditions. Within their digestive tissues, our results showed that SARS-CoV-2 genome was detected in zebra mussels, whether in raw and treated wastewaters. Moreover, the detection of the SARS-CoV-2 genome in such bivalve molluscans appeared even with low concentrations in raw wastewaters. This is the first detection of the SARS-CoV-2 genome in the tissues of a sentinel species exposed to raw and treated urban wastewaters. Despite the need for development for quantitative approaches, these results support the importance of such invertebrate organisms, especially zebra mussel, for the active surveillance of pathogenic microorganisms and their indicators in environmental waters.

Risk Analysis by Failure Modes, Effects and Criticality Analysis and Biosafety Management During Collective Air Medical Evacuation of Critically Ill Coronavirus Disease 2019 Patients

In March 2020, coronavirus disease 2019 (COVID-19) caused an overwhelming pandemic. To relieve overloaded intensive care units in the most affected regions, the French Ministry of Defence triggered collective air medical evacuations (medevacs) on board an Airbus A330 Multi Role Tanker Transport of the French Air Force. Such a collective air medevac is a big challenge regarding biosafety; until now, only evacuations of a single symptomatic patient with an emergent communicable disease, such as Ebola virus disease, have been conducted. However, the COVID-19 pandemic required collective medevacs for critically ill patients and involved a virus that little is known about still. Thus, we performed a complete risk analysis using a process map and FMECA (Failure Modes, Effects and Criticality Analysis) to assess the risk and implement mitigation measures for health workers, flight crew, and the environment. We report the biosafety management experienced during 6 flights with a total of 36 critically ill COVID-19-positive patients transferred with no casualties while preserving both staffs and aircraft.

Challenges and emerging perspectives of an international SARS-CoV-2 epidemiological surveillance in wastewater

SARS-CoV-2 is a new type of coronavirus capable to infect humans and cause the severe acute respiratory syndrome COVID-19, a disease that has been causing huge impacts across the Earth. COVID-19 patients, including mild, pre-symptomatic and asymptomatic cases, were often seen to contain infectious fragments of SARS-CoV-2 in feces and urine samples. Therefore, studies to detect the new coronavirus in wastewater, which collect and concentrate human excreta, have been extremely useful as a viral tracking tool in communities. This type of monitoring, in addition to serve as a non-invasive early warning of COVID-19 outbreaks, would provide better predictions about the SARS-CoV-2 spread and strongly contribute to maintenance the global health. Although current methods to detect viruses in wastewater, based on molecular RT-PCR and RT-qPCR techniques, were considered as reliable and provided accurate qualitative and quantitative results, they have been facing considerable challenges concerning the SARS-CoV-2 surveillance. In this review, the methods used to detect the SARS-CoV-2 in wastewater and the challenges to implement an international viral monitoring network were described. The article also addressed the emerging perspectives associated with the SARS-CoV-2 epidemiological surveillance in this environment and the importance of a worldwide collaboration to generate and disseminate the detection results.

Surface contamination with SARS-CoV-2: A systematic review

Little is known about contaminated surfaces as a route of transmission for SARS-CoV- 2 and a systematic review is missing and urgently needed to provide guidelines for future research studies. As such, the aim of the present study was to review the current scientific knowledge and to summarize the existing studies in which SARS-CoV-2 has been detected in inanimate surfaces. This systematic review includes studies since the emergence of SARS-CoV-2, available in PubMed/MEDLINE and Scopus. Duplicate publications were removed, and exclusion criteria was applied to eliminate unrelated studies, resulting in 37 eligible publications. The present study provides the first overview of SARS-CoV-2 detection in surfaces. The highest detection rates occurred in hospitals and healthcare facilities with COVID-19 patients. Contamination with SARS-CoV-2 on surfaces was detected in a wide range of facilities and surfaces. There is a lack of studies performing viability testing for SARS-CoV-2 recovered from surfaces, and consequently it is not yet possible to assess the potential for transmission via surfaces.

Surface and air contamination with SARS-CoV-2 from hospitalized COVID-19 patients in Toronto, Canada, March-May 2020

Background

We determined the burden of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in air and on surfaces in rooms of patients hospitalized with coronavirus disease 2019 (COVID-19) and investigated patient characteristics associated with SARS-CoV-2 environmental contamination.

Methods

Nasopharyngeal swabs, surface, and air samples were collected from the rooms of 78 inpatients with COVID-19 at 6 acute care hospitals in Toronto from March to May 2020. Samples were tested for SARS-CoV-2 ribonucleic acid (RNA), cultured to determine potential infectivity, and whole viral genomes were sequenced. Association between patient factors and detection of SARS-CoV-2 RNA in surface samples were investigated.

Results

Severe acute respiratory syndrome coronavirus 2 RNA was detected from surfaces (125 of 474 samples; 42 of 78 patients) and air (3 of 146 samples; 3 of 45 patients); 17% (6 of 36) of surface samples from 3 patients yielded viable virus. Viral sequences from nasopharyngeal and surface samples clustered by patient. Multivariable analysis indicated hypoxia at admission, polymerase chain reaction-positive nasopharyngeal swab (cycle threshold of ≤30) on or after surface sampling date, higher Charlson comorbidity score, and shorter time from onset of illness to sampling date were significantly associated with detection of SARS-CoV-2 RNA in surface samples.

Conclusions

The infrequent recovery of infectious SARS-CoV-2 virus from the environment suggests that the risk to healthcare workers from air and near-patient surfaces in acute care hospital wards is likely limited.

The existence, spread, and strategies for environmental monitoring and control of SARS-CoV-2 in environmental media

Coronavirus disease 2019 (COVID-19) is the most influential infectious disease to emerge in the early 21st century. The outbreak of COVID-19 has caused a great many deaths and has had a negative impact on the world's economic development. The etiological agent of COVID-19 is severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2, which is highly infectious and variable, can be transmitted through different environmental media (gaseous, liquid, and solid). There are many unanswered questions surrounding this virus. This review summarizes the current knowledge on the latest global COVID-19 epidemic situation, SARS-CoV-2 variants, the progress in SARS-CoV-2 vaccine use, and the existence and spread of SARS-CoV-2 in gaseous, liquid, and solid media, with particular emphasis on the prevention and control of further spread of the disease. This review aims to help people worldwide to become more familiar with the transmission characteristics of SARS-CoV-2 in environmental media, so as targeted measures to fight the epidemic, reduce deaths, and restore the economy can be implemented under the pressure of global SARS-CoV-2 vaccine shortages.

Potential of an Eco-Sustainable Probiotic-Cleaning Formulation in Reducing Infectivity of Enveloped Viruses

The COVID-19 pandemic has deeply influenced sanitization procedures, and high-level disinfection has been massively used to prevent SARS-CoV-2 spread, with potential negative impact on the environment and on the threat of antimicrobial resistance (AMR). Aiming to overcome these concerns, yet preserving the effectiveness of sanitization against enveloped viruses, we assessed the antiviral properties of the Probiotic Cleaning Hygiene System (PCHS), an eco-sustainable probiotic-based detergent previously proven to stably abate pathogen contamination and AMR. PCHS (diluted 1:10, 1:50 and 1:100) was tested in comparison to common disinfectants (70% ethanol and 0.5% sodium hypochlorite), in suspension and carrier tests, according with the European UNI EN 14476:2019 and UNI EN 16777:2019 standards. Human alpha- and beta-coronaviruses hCoV-229E and SARS-CoV-2, human herpesvirus type 1, human and animal influenza viruses, and vaccinia virus were included in the study. The results showed that PCHS was able to inactivate 99.99% of all tested viruses within 1-2 h of contact, both in suspension and on surface. Notably, while control disinfectants became inactive within 2 h after application, the PCHS antiviral action persisted up to 24 h post-application, suggesting that its use may effectively allow a continuous prevention of virus spread via contaminated environment, without worsening environmental pollution and AMR concern.

Environmental Surveillance and Transmission Risk Assessments for SARS-CoV-2 in a Fitness Center

Fitness centers are considered high risk for SARS-CoV-2 transmission due to their high human occupancy and the type of activity taking place in them, especially when individuals pre-symptomatic or asymptomatic for COVID-19 exercise in the facilities. In this study, air (N=21) and surface (N=8) samples were collected at a fitness center through five sampling events from August to November 2020 after the reopening restrictions were lifted in Florida. The total attendance was ~2500 patrons during our air and environmental sampling work. Air samples were collected using stationary and personal bioaerosol samplers. Moistened flocked nylon swabs were used to collect samples from high-touch surfaces. We did not detect SARS-CoV-2 by rRT-PCR analyses in any air or surface sample. A simplified infection risk model based on the Wells-Riley equation predicts that the probability of infection in this fitness center was 1.77% following its ventilation system upgrades based on CDC guidelines, and that risk was further reduced to 0.89% when patrons used face masks. Our model also predicts that a combination of high ventilation, minimal air recirculation, air filtration, and UV sterilization of recirculated air reduced the infection risk up to 94% compared to poorly ventilated facilities. Amongst these measures, high ventilation with outdoor air is most critical in reducing the airborne transmission of SARS-CoV-2. For buildings that cannot avoid air recirculation due to energy costs, the use of high filtration and/or air disinfection devices are alternatives to reducing the probability of acquiring SARS-CoV-2 through inhalation exposure. In contrast to the perceived ranking of high risk, the infection risk in fitness centers that follow CDC reopening guidance, including implementation of engineering and administrative controls, and use of personal protective equipment, can be low, and these facilities can offer a relatively safe venue for patrons to exercise.

Technical framework for wastewater-based epidemiology of SARS-CoV-2

Wastewater-based epidemiology (WBE) is expected to become a powerful tool to monitor the dissemination of SARS-CoV-2 at the community level, which has attracted the attention of scholars all over the world. However, there is not yet a standard protocol to guide its implementation. In this paper, we proposed a comprehensive technical and theoretical framework of relative quantification via qPCR for determining the virus abundance in wastewater and estimating the infection ratio in corresponding communities, which is expected to achieve horizontal and vertical comparability of the data using a human-specific biomarker as the internal reference. Critical factors affecting the virus detectability and the estimation of infection ratio include virus concentration methods, lag-period, per capita virus shedding amount, sewage generation rate, temperature-related decay kinetics of virus/biomarker in wastewater, and hydraulic retention time (HRT), etc. Theoretical simulation shows that the main factors affecting the detectability of virus in sewage are per capita virus shedding amount and sewage generation rate. While the decay of SARS-CoV-2 RNA in sewage is a relatively slow process, which may have limited impact on its detection. Under the ideal condition of high per capita virus shedding amount and low sewage generation rate, it is expected to detect a single infected person within 400,000 people.

Infection Control in the Era of COVID-19: A Narrative Review

COVID-19 quickly became a pandemic causing millions of infections and mortalities. It required real-time adjustments to healthcare systems and infection prevention and control (IPC) measures to limit the spread and protect healthcare providers and hospitalized patients. IPC guidelines were adopted and developed based on experience gained during the MERS-CoV and SARS-CoV outbreaks. The aim of this narrative review is to summarize current evidence on IPC in healthcare settings and patients with COVID-19 to prevent nosocomial infections during the actual pandemic. A search was run on PubMed using the terms (‘COVID-19’ [Mesh]) AND (‘Infection Control’ [Mesh]) between 2019 and 2021. We identified 86 studies that were in accordance with our aim and summarized them under certain themes as they related to COVID-19 infection control measures. All the guidelines recommend early diagnosis and rapid isolation of COVID-19 patients. The necessary precautions should be taken comprising the whole process, starting with an infectious disease plan, administrative and engineering controls, triage, and PPE training. Guidelines should target modes of transmission, droplet, aerosol, and oral–fecal, while recommending control precautions. Healthcare facilities must promptly implement a multidisciplinary defense system to combat the outbreak.

The first case study of wastewater-based epidemiology of COVID-19 in Hong Kong

Early detection and surveillance of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) virus are key pre-requisites for the effective control of coronavirus disease (COVID-19). So far, sewage testing has been increasingly employed as an alternative surveillance tool for this disease. However, sampling site characteristics impact the testing results and should be addressed in the early use stage of this emerging tool. In this study, we implemented the sewage testing for SARS-CoV-2 virus across sampling sites with different sewage system characteristics. We first validated a testing method using "positive" samples from a hospital treating COVID-19 patients. This method was used to test 107 sewage samples collected during the third wave of the COVID-19 outbreak in Hong Kong (from June 8 to September 29, 2020), covering sampling sites associated with a COVID-19 hospital, public housing estates, and conventional sewage treatment facilities. The highest viral titer of 1975 copy/mL in sewage was observed in a sample collected from the isolation ward of the COVID-19 hospital. Sewage sampling at individual buildings detected the virus 2 days before the first cases were identified. Sequencing of the detected viral fragment confirmed an identical nucleotide sequence to that of the SARS-CoV-2 isolated from human samples. The virus was also detected in sewage treatment facilities, which serve populations of approximately 40,000 to more than one million people.

Contamination of Air and Surfaces in Workplaces with SARS-CoV-2 Virus: A Systematic Review

OBJECTIVES

This systematic review aimed to evaluate the evidence for air and surface contamination of workplace environments with SARS-CoV-2 RNA and the quality of the methods used to identify actions necessary to improve the quality of the data.

METHODS

We searched Web of Science and Google Scholar until 24 December 2020 for relevant articles and extracted data on methodology and results.

RESULTS

The vast majority of data come from healthcare settings, with typically around 6% of samples having detectable concentrations of SARS-CoV-2 RNA and almost none of the samples collected had viable virus. There were a wide variety of methods used to measure airborne virus, although surface sampling was generally undertaken using nylon flocked swabs. Overall, the quality of the measurements was poor. Only a small number of studies reported the airborne concentration of SARS-CoV-2 virus RNA, mostly just reporting the detectable concentration values without reference to the detection limit. Imputing the geometric mean air concentration assuming the limit of detection was the lowest reported value, suggests typical concentrations in healthcare settings may be around 0.01 SARS-CoV-2 virus RNA copies m-3. Data on surface virus loading per unit area were mostly unavailable.

CONCLUSIONS

The reliability of the reported data is uncertain. The methods used for measuring SARS-CoV-2 and other respiratory viruses in work environments should be standardized to facilitate more consistent interpretation of contamination and to help reliably estimate worker exposure.

Investigating Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Surface and Air Contamination in an Acute Healthcare Setting During the Peak of the Coronavirus Disease 2019 (COVID-19) Pandemic in London

BACKGROUND

We evaluated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) surface and air contamination during the coronavirus disease 2019 (COVID-19) pandemic in London.

METHODS

Prospective, cross-sectional, observational study in a multisite London hospital. Air and surface samples were collected from 7 clinical areas occupied by patients with COVID-19 and a public area of the hospital. Three or four 1.0-m3 air samples were collected in each area using an active air sampler. Surface samples were collected by swabbing items in the immediate vicinity of each air sample. SARS-CoV-2 was detected using reverse-transcription quantitative polymerase chain reaction (PCR) and viral culture; the limit of detection for culturing SARS-CoV-2 from surfaces was determined.

RESULTS

Viral RNA was detected on 114 of 218 (52.3%) surfaces and in 14 of 31 (38.7%) air samples, but no virus was cultured. Viral RNA was more likely to be found in areas immediately occupied by COVID-19 patients than in other areas (67 of 105 [63.8%] vs 29 of 64 [45.3%]; odds ratio, 0.5; 95% confidence interval, 0.2-0.9; P = .025, χ2 test). The high PCR cycle threshold value for all samples (>30) indicated that the virus would not be culturable.

CONCLUSIONS

Our findings of extensive viral RNA contamination of surfaces and air across a range of acute healthcare settings in the absence of cultured virus underlines the potential risk from environmental contamination in managing COVID-19 and the need for effective use of personal protective equipment, physical distancing, and hand/surface hygiene.

The impact of coronavirus SARS-CoV-2 (COVID-19) in water: potential risks

This review summarizes research data on SARS-CoV-2 in water environments. A literature survey was conducted using the electronic databases Science Direct, Scopus, and Springer. This complete research included and discussed relevant studies that involve the (1) introduction, (2) definition and features of coronavirus, (2.1) structure and classification, (3) effects on public health, (4) transmission, (5) detection methods, (6) impact of COVID-19 on the water sector (drinking water, cycle water, surface water, wastewater), (6.5) wastewater treatment, and (7) future trends. The results show contamination of clean water sources, and community drinking water is vulnerable. Additionally, there is evidence that sputum, feces, and urine contain SARS-CoV-2, which can maintain its viability in sewage and the urban-rural water cycle to move towards seawater or freshwater; thus, the risk associated with contracting COVID-19 from contact with untreated water or inadequately treated wastewater is high. Moreover, viral loads have been detected in surface water, although the risk is lower for countries that efficiently treat their wastewater. Further investigation is immediately required to determine the persistence and mobility of SARS-CoV-2 in polluted water and sewage as well as the possible potential of disease transmission via drinking water. Conventional wastewater treatment systems have been shown to be effective in removing the virus, which plays an important role in pandemic control. Monitoring of this virus in water is extremely important as it can provide information on the prevalence and distribution of the COVID-19 pandemic in different communities as well as possible infection dynamics to prevent future outbreaks.

Factors Affecting COVID-19 Transmission and Modelling of Close Contact Tracing Strategies

BACKGROUND

Close contact tracing is an essential measure that countries are applying to combat the epidemic of COVID-19. The purpose of contact tracing is to rapidly identify potentially infected individuals and prevent further spread of the disease. In this study, based on the factors affecting the COVID-19 transmission, a scoring protocol is provided for close contact tracing.

METHODS

First, the factors affecting the COVID-19 transmission in close contacts were identified by a rapid review of the literature. Data were gathered by searching the Embase, PubMed, Google Scholar, and Scopus databases. Then, by formulating and scoring the identified factors with two sessions of the expert panel, close contact transmission risk score determined, and a protocol for contacts tracing was designed.

RESULTS

Close contact transmission risk depends on the contact environment characteristics, the infectivity (virus shedding) of the sentinel case, and contact characteristics. Based on these factors, the close contact transmission risk score and contact tracing protocol were prepared.

CONCLUSION

The close contact transmission risk scores will provide the ability to contact classifications and developing specific tracing strategies for them. Given that there are not any specific treatments for COVID-19 and lack of universal vaccination, applying nonpharmaceutical measures such as contact tracing along with physical distancing is very crucial. Therefore, we recommended this model to the evaluation of exposure risk and contact tracing.

Effervescent ferrate(VI)-based tablets as an effective means for removal SARS-CoV-2 RNA, pharmaceuticals and resistant bacteria from wastewater

Waterborne pathogens including viruses, bacteria and micropollutants secreted from population can spread through the sewerage system. In this study, the efficiency of unique effervescent ferrate-based tablets was evaluated for total RNA and DNA removal, disinfection and degradation of micropollutants in hospital wastewater. For the purpose of testing, proposed tablets (based on citric acid or sodium dihydrogen phosphate) were used for various types of hospital wastewater with specific biological and chemical contamination. Total RNA destruction efficiency using tablets was 70-100% depending on the type of acidic component. DNA destruction efficiency was lower on the level 51-94% depending on the type of acidic component. In addition, our study confirms that effervescent ferrate-based tablets are able to efficiently remove of SARS-CoV-2 RNA from wastewater. Degradation of often detected micropollutants (antiepileptic, antidepressant, antihistamine, hypertensive and their metabolites) was dependent on the type of detected pharmaceuticals and on the acidic component used. Sodium dihydrogen phosphate based tablet appeared to be more effective than citric acid based tablet and removed some pharmaceuticals with efficiency higher than 97%. Last but not least, the disinfection ability was also verified. Tableted ferrates were confirmed to be an effective disinfectant and no resistant microorganisms were observed after treatment. Total and antibiotic resistant bacteria (coliforms and enterococci) were determined by cultivation on diagnostic selective agar growth media.

Targeted wastewater surveillance of SARS-CoV-2 on a university campus for COVID-19 outbreak detection and mitigation

Targeted wastewater surveillance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been proposed by the United States Centers for Disease Control and Prevention's National Wastewater Surveillance System as a complementary approach to clinical surveillance to detect the presence of Coronavirus Disease 2019 (COVID-19) at high-density facilities and institutions such as university campuses, nursing homes, and correctional facilities. In this study we evaluated the efficacy of targeted wastewater surveillance of SARS-CoV-2 RNA together with individual-level testing for outbreak mitigation on a university campus during Fall 2020 semester. Wastewater samples (n = 117) were collected weekly from manholes or sewer cleanouts that receive wastewater inputs from dormitories, community-use buildings, and a COVID-19 isolation dormitory. Quantitative RT-PCR N1 and N2 assays were used to measure SARS-CoV-2 nucleocapsid genes in wastewater. Due to varying human waste input in different buildings, pepper mild mottle virus (PMMV) RNA was also measured in all samples and used to normalize SARS-CoV-2 N1 and N2 RNA wastewater concentrations. In this study, temporal trends of SARS-CoV-2 in wastewater samples mirrored trends in COVID-19 cases detected on campus. Normalizing SARS-CoV-2 RNA concentrations using human fecal indicator, PMMV enhanced the correlation between N1 and N2 gene abundances in wastewater with COVID-19 cases. N1 and N2 genes were significant predictors of COVID-19 cases in dormitories, and the N2 gene was significantly correlated with the number of detected COVID-19 cases in dormitories. By implementing several public health surveillance programs include targeted wastewater surveillance, individual-level testing, contact tracing, and quarantine/isolation facilities, university health administrators could act decisively during an outbreak on campus, resulting in rapid decline of newly detected COVID-19 cases. Wastewater surveillance of SARS-CoV-2 is a proactive outbreak monitoring tool for university campuses seeking to continue higher education practices in person during the COVID-19 pandemic.

The role of airborne particles and environmental considerations in the transmission of SARS-CoV-2

Corona Virus Disease 2019 (COVID-19) caused by the novel coronavirus, results in an acute respiratory condition coronavirus 2 (SARS-CoV-2) and is highly infectious. The recent spread of this virus has caused a global pandemic. Currently, the transmission routes of SARS-CoV-2 are being established, especially the role of environmental transmission. Here we review the environmental transmission routes and persistence of SARS-CoV-2. Recent studies have established that the transmission of this virus may occur, amongst others, in the air, water, soil, cold-chain, biota, and surface contact. It has also been found that the survival potential of the SARS-CoV-2 virus is dependent on different environmental conditions and pollution. Potentially important pathways include aerosol and fecal matter. Particulate matter may also be a carrier for SARS-CoV-2. Since microscopic particles can be easily absorbed by humans, more attention must be focused on the dissemination of these particles. These considerations are required to evolve a theoretical platform for epidemic control and to minimize the global threat from future epidemics.

Capacity of existing wastewater treatment plants to treat SARS-CoV-2. A review

Water is one of many viral transmission routes, and the presence of Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2) in wastewater has brought attention to its treatment. SARS CoV-2 primarily transmits in the air but the persistence of the virus in the water possibly can serve as a secondary source even though current studies do not show this. In this paper, an evaluation of the current literature with regards to the treatment of SARS-CoV-2 in wastewater treatment plant (WWTP) effluents and biosolids is presented. Treatment efficiencies of WWTPs are compared for viral load reduction on the basis of publicly available data. The results of this evaluation indicate that existing WWTPs are effectively removing 1-6 log10 viable SARS-CoV-2. However, sludge and biosolids provide an umbrella of protection from treatment and inactivation to the virus. Hence, sludge treatment factors like high temperature, pH changes, and predatory microorganisms can effectively inactivate SARS-CoV-2.

Methods Evaluation for Rapid Concentration and Quantification of SARS-CoV-2 in Raw Wastewater Using Droplet Digital and Quantitative RT-PCR

Wastewater surveillance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emerging public health tool to understand the spread of Coronavirus Disease 2019 (COVID-19) in communities. The performance of different virus concentration methods and PCR methods needs to be evaluated to ascertain their suitability for use in the detection of SARS-CoV-2 in wastewater. We evaluated ultrafiltration and polyethylene glycol (PEG) precipitation methods to concentrate SARS-CoV-2 from sewage in wastewater treatment plants and upstream in the wastewater network (e.g., manholes, lift stations). Recovery of viruses by different concentration methods was determined using Phi6 bacteriophage as a surrogate for enveloped viruses. Additionally, the presence of SARS-CoV-2 in all wastewater samples was determined using reverse transcription quantitative PCR (RT-qPCR) and reverse transcription droplet digital PCR (RT-ddPCR), targeting three genetic markers (N1, N2 and E). Using spiked samples, the Phi6 recoveries were estimated at 2.6-11.6% using ultrafiltration-based methods and 22.2-51.5% using PEG precipitation. There was no significant difference in recovery efficiencies (p < 0.05) between the PEG procedure with and without a 16 h overnight incubation, demonstrating the feasibility of obtaining same day results. The SARS-CoV-2 genetic markers were more often detected by RT-ddPCR than RT-qPCR with higher sensitivity and precision. While all three SARS-CoV-2 genetic markers were detected using RT-ddPCR, the levels of E gene were almost below the limit of detection using RT-qPCR. Collectively, our study suggested PEG precipitation is an effective low-cost procedure which allows a large number of samples to be processed simultaneously in a routine wastewater monitoring for SARS-CoV-2. RT-ddPCR can be implemented for the absolute quantification of SARS-CoV-2 genetic markers in different wastewater matrices.

Monitoring the presence and persistence of SARS-CoV-2 in water-food-environmental compartments: State of the knowledge and research needs

The recent spread of severe acute respiratory syndrome coronavirus (SAR-CoV-2) and the accompanied coronavirus disease 2019 (COVID-19) has continued ceaselessly despite the implementations of popular measures, which include social distancing and outdoor face masking as recommended by the World Health Organization. Due to the unstable nature of the virus, leading to the emergence of new variants that are claimed to be more and rapidly transmissible, there is a need for further consideration of the alternative potential pathways of the virus transmissions to provide the needed and effective control measures. This review aims to address this important issue by examining the transmission pathways of SARS-CoV-2 via indirect contacts such as fomites and aerosols, extending to water, food, and other environmental compartments. This is essentially required to shed more light regarding the speculation of the virus spread through these media as the available information regarding this is fragmented in the literature. The existing state of the information on the presence and persistence of SARS-CoV-2 in water-food-environmental compartments is essential for cause-and-effect relationships of human interactions and environmental samples to safeguard the possible transmission and associated risks through these media. Furthermore, the integration of effective remedial measures previously used to tackle the viral outbreaks and pandemics, and the development of new sustainable measures targeting at monitoring and curbing the spread of SARS-CoV-2 were emphasized. This study concluded that alternative transmission pathways via human interactions with environmental samples should not be ignored due to the evolving of more infectious and transmissible SARS-CoV-2 variants.

Environmental Surface Contamination with SARS-CoV-2: Toilets as the Most Contaminated Surfaces in COVID-19 Referral Hospital

INTRODUCTION

The possibility of surface transmission in hospitals with high density of COVID- 19 patients is unneglectable. The aim of this study is to determine the extent of surface contamination in coronavirus central hospital of Ilam province in western Iran.

MATERIALS AND METHODS

In this experimental study, 205 samples were taken from environmental surfaces in hospital. SARS-CoV-2 RNA detected by Real-time RT-PCR.

RESULTS

121 out of 205 (50.02%) samples were positive. The most contaminated objects were toilet sites (5/5,100% ICU; 5/5, 100% isolation wards).

CONCLUSION

High surface contamination with SARS-CoV-2 proposes the surface as a potential route of transmission.

Wastewater Based Epidemiology Perspective as a Faster Protocol for Detecting Coronavirus RNA in Human Populations: A Review with Specific Reference to SARS-CoV-2 Virus

Wastewater-based epidemiology (WBE) has a long history of identifying a variety of viruses from poliovirus to coronaviruses, including novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The presence and detection of SARS-CoV-2 in human feces and its passage into the water bodies are significant public health challenges. Hence, the hot issue of WBE of SARS-CoV-2 in the coronavirus respiratory disease (COVID-19) pandemic is a matter of utmost importance (e.g., SARS-CoV-1). The present review discusses the background, state of the art, actual status, and prospects of WBE, as well as the detection and quantification protocols of SARS-CoV-2 in wastewater. The SARS-CoV-2 detection studies have been performed in different water matrixes such as influent and effluent of wastewater treatment plants, suburban pumping stations, hospital wastewater, and sewer networks around the globe except for Antarctica. The findings revealed that all WBE studies were in accordance with clinical and epidemiological data, which correlates the presence of SARS-CoV-2 ribonucleic acid (RNA) with the number of new daily positive cases officially reported. This last was confirmed via Reverse Transcriptase-quantitative Polymerase Chain Reaction (RT-qPCR) testing which unfortunately is not suitable for real-time surveillance. In addition, WBE concept may act as a faster protocol to alert the public health authorities to take administrative orders (possible re-emerging infections) due to the impracticality of testing all citizens in a short time with limited diagnostic facilities. A comprehensive and integrated review covering all steps starting from sampling to molecular detection of SARS-CoV-2 in wastewater has been made to guide for the development well-defined and reliable protocols.

Coronavirus in water media: Analysis, fate, disinfection and epidemiological applications

Considerable attention has been recently given to possible transmission of SARS-CoV-2 via water media. This review addresses this issue and examines the fate of coronaviruses (CoVs) in water systems, with particular attention to the recently available information on the novel SARS-CoV-2. The methods for the determination of viable virus particles and quantification of CoVs and, in particular, of SARS-CoV-2 in water and wastewater are discussed with particular regard to the methods of concentration and to the emerging methods of detection. The analysis of the environmental stability of CoVs, with particular regard of SARS-CoV-2, and the efficacy of the disinfection methods are extensively reviewed as well. This information provides a broad view of the state-of-the-art for researchers involved in the investigation of CoVs in aquatic systems, and poses the basis for further analyses and discussions on the risk associated to the presence of SARS-CoV-2 in water media. The examined data indicates that detection of the virus in wastewater and natural water bodies provides a potentially powerful tool for quantitative microbiological risk assessment (QMRA) and for wastewater-based epidemiology (WBE) for the evaluation of the level of circulation of the virus in a population. Assays of the viable virions in water media provide information on the integrity, capability of replication (in suitable host species) and on the potential infectivity. Challenges and critical issues relevant to the detection of coronaviruses in different water matrixes with both direct and surrogate methods as well as in the implementation of epidemiological tools are presented and critically discussed.

The first detection of SARS-CoV-2 RNA in the wastewater of Tehran, Iran

Following the official announcement of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) worldwide pandemic spread by WHO on March 11, 2020, more than 300,000 COVID-19 cases reported in Iran resulting in approximately 17,000 deaths as of August 2, 2020. In the present survey, we investigated the presence of SARS-CoV-2 RNA in raw and treated wastewater samples in Tehran, Iran. Untreated and treated wastewater samples were gathered from four wastewater treatment plants over a month period from June to July 2020. Firstly, an adsorption-elution concentration method was tested using an avian coronavirus (infectious bronchitis virus, IBV). Then, the method was effectively employed to survey the presence of SARS-CoV-2 genome in influent and effluent wastewater samples. SARS-CoV-2 RNA was found in 8 out of 10 treated wastewater samples utilizing a reverse transcription-quantitative polymerase chain reaction (RT-qPCR) test to detect ORF1ab and N genes. Moreover, the rate of positivity in wastewater samples increased in last sample collection that shows circulation of SARS-CoV-2 was increased among the population. In addition, the high values detected in effluent wastewater from local wastewater treatment plants have several implications in health and ecology that should be further assessed.

Water science under the global epidemic of COVID-19: Bibliometric tracking on COVID-19 publication and further research needs

There are overwhelming increases of studies and over 200,000 publications related to all the aspects of COVID-19. Among them, 262 papers were published by authors from 67 countries regarding COVID-19 with water science and technology. Although the transmission routes of SARS-CoV-2 in water cycle have not been proved, the water and wastewater play an important role in the control of COVID-19 pandemic. Accordingly, it is scholarly relevant and interesting to look into publications of COVID-19 in water science and technology to track the investigations for moving forward in the years to come. It is believed that, through the literature survey, the question on what we know and what we do not know about COVID-19 so far can be clear, thus providing useful information for helping curbing the epidemic from water sector. This forms the basis of the current study. As such, a bibliometric analysis was conducted. It reveals that wastewater-based epidemiology (WBE) has recently gained global attention with the source and survival characteristics of coronavirus in the aquatic environment; the methodology of virus detection; the water hygiene; and the impact of the COVID-19 pandemic on the water ecosystem being the main topics in 2020. Various studies have shown that drinking water is safety whereas wastewater may be a potential risk during this pandemic. From the perspective of the water cycle, the scopes for further research needs are discussed and proposed, which could enhance the important role and value of water science in warning, monitoring, and predicting COVID-19 during epidemic outbreaks.

Sewage Systems Surveillance for SARS-CoV-2: Identification of Knowledge Gaps, Emerging Threats, and Future Research Needs

The etiological agent for novel coronavirus (COVID-19, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), not only affects the human respiratory system, but also the gastrointestinal tract resulting in gastrointestinal manifestations. The high rate of asymptomatic infected individuals has challenged the estimation of infection spread based on patients' surveillance, and thus alternative approaches such as wastewater-based epidemiology (WBE) have been proposed. Accordingly, the number of publications on this topic has increased substantially. The present systematic review thus aimed at providing state-of-the-knowledge on the occurrence and existing methods for sampling procedures, detection/quantification of SARS-CoV-2 in sewage samples, as well as anticipating challenges and providing future research direction to improve the current scientific knowledge. Articles were collected from three scientific databases. Only studies reporting measurements of virus in stool, urine, and wastewater samples were included. Results showed that improving the scientific community's understanding in these avenues is essential if we are to develop appropriate policy and management tools to address this pandemic pointing particularly towards WBE as a new paradigm in public health. It was also evident that standardized protocols are needed to ensure reproducibility and comparability of outcomes. Areas that require the most improvements are sampling procedures, concentration/enrichment, detection, and quantification of virus in wastewater, as well as positive controls. Results also showed that selecting the most accurate population estimation method for WBE studies is still a challenge. While the number of people infected in an area could be approximately estimated based on quantities of virus found in wastewater, these estimates should be cross-checked by other sources of information to draw a more comprehensive conclusion. Finally, wastewater surveillance can be useful as an early warning tool, a management tool, and/or a way for investigating vaccination efficacy and spread of new variants.

Sewage Systems Surveillance for SARS-CoV-2: Identification of Knowledge Gaps, Emerging Threats, and Future Research Needs

The etiological agent for novel coronavirus (COVID-19, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), not only affects the human respiratory system, but also the gastrointestinal tract resulting in gastrointestinal manifestations. The high rate of asymptomatic infected individuals has challenged the estimation of infection spread based on patients' surveillance, and thus alternative approaches such as wastewater-based epidemiology (WBE) have been proposed. Accordingly, the number of publications on this topic has increased substantially. The present systematic review thus aimed at providing state-of-the-knowledge on the occurrence and existing methods for sampling procedures, detection/quantification of SARS-CoV-2 in sewage samples, as well as anticipating challenges and providing future research direction to improve the current scientific knowledge. Articles were collected from three scientific databases. Only studies reporting measurements of virus in stool, urine, and wastewater samples were included. Results showed that improving the scientific community's understanding in these avenues is essential if we are to develop appropriate policy and management tools to address this pandemic pointing particularly towards WBE as a new paradigm in public health. It was also evident that standardized protocols are needed to ensure reproducibility and comparability of outcomes. Areas that require the most improvements are sampling procedures, concentration/enrichment, detection, and quantification of virus in wastewater, as well as positive controls. Results also showed that selecting the most accurate population estimation method for WBE studies is still a challenge. While the number of people infected in an area could be approximately estimated based on quantities of virus found in wastewater, these estimates should be cross-checked by other sources of information to draw a more comprehensive conclusion. Finally, wastewater surveillance can be useful as an early warning tool, a management tool, and/or a way for investigating vaccination efficacy and spread of new variants.

Prevalence and stability of SARS-CoV-2 RNA on Bangladeshi banknotes

Originating in December 2019 in China, SARS-CoV-2 has emerged as the deadliest pandemic in humankind's history. Along with direct contact and droplet contaminations, the possibility of infections through contaminated surfaces and fomites is investigating. This study aims to assess SARS-CoV-2 viral RNA's prevalence by real-time one-step reverse transcriptase PCR on banknotes circulating in Bangladesh. We also evaluated the persistence of the virus on banknotes spiked with SARS-CoV-2 positive diluted human nasopharyngeal samples. Among the 425 banknote samples collected from different entities, 7.29% (n = 31) were tested positive for targeted genes. Twenty-four positive representative samples were assessed for n gene fragments by conventional PCR and sequenced. All the samples that carry viral RNA belonged to the GR clade, the predominantly circulating clade in Bangladesh. In the stability test, the n gene was detected for up to 72 h on banknotes spiked with nasopharyngeal samples, and CT values increase significantly with time (p < 0.05). orf1b gene was observed to be less stable, especially on old banknotes, and usually went beyond detectable limit within 8 to 10 h. The stability of virus RNA well fitted by the Weibull model and concave curve for new banknotes and convex curve for old banknotes revealed. Handling banknotes is unavoidable; hence, these findings imply that proper hygiene practice is needed to limit SARS-CoV-2 transmission through banknotes.

Can shellfish be used to monitor SARS-CoV-2 in the coastal environment?

The emergence and worldwide spread of SARS-CoV-2 raises new concerns and challenges regarding possible environmental contamination by this virus through spillover of human sewage, where it has been detected. The coastal environment, under increasing anthropogenic pressure, is subjected to contamination by a large number of human viruses from sewage, most of them being non-enveloped viruses like norovirus. When reaching coastal waters, they can be bio-accumulated by filter-feeding shellfish species such as oysters. Methods to detect this viral contamination were set up for the detection of non-enveloped enteric viruses, and may need optimization to accommodate enveloped viruses like coronaviruses (CoV). Here, we aimed at assessing methods for the detection of CoV, including SARS-CoV-2, in the coastal environment and testing the possibility that SARS-CoV-2 can contaminate oysters, to monitor the contamination of French shores by SARS-CoV-2 using both seawater and shellfish. Using the porcine epidemic diarrhea virus (PEDV), a CoV, as surrogate for SARS-CoV-2, and Tulane virus, as surrogate for non-enveloped viruses such as norovirus, we assessed and selected methods to detect CoV in seawater and shellfish. Seawater-based methods showed variable and low yields for PEDV. In shellfish, the current norm for norovirus detection was applicable to CoV detection. Both PEDV and heat-inactivated SARS-CoV-2 could contaminate oysters in laboratory settings, with a lower efficiency than a calicivirus used as control. Finally, we applied our methods to seawater and shellfish samples collected from April to August 2020 in France, where we could detect the presence of human norovirus, a marker of human fecal contamination, but not SARS-CoV-2. Together, our results validate methods for the detection of CoV in the coastal environment, including the use of shellfish as sentinels of the microbial quality of their environment, and suggest that SARS-CoV-2 did not contaminate the French shores during the summer season.

Prevalence, environmental fate, treatment strategies, and future challenges for wastewater contaminated with SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been detected in untreated and treated wastewater and studies have shown that the concentration of SARS-CoV-2 is proportional to the prevalence of the coronavirus disease 2019 (COVID-19) in communities. This article presents a literature review of the prevalence of SARS-CoV-2 in wastewater, its environmental fate, recommended treatment strategies for contaminated wastewater, and treatment challenges to be faced in the future. The environmental fate of SARS-CoV-2 in wastewater is not straightforward because it can be a source of infection when present in the treated wastewater depending on the permeability of the wastewater treatment plant containment area, and can also leach into aquifers, which may serve as drinking water supplies. Secondly, there are different practices that can mitigate the SARS-CoV-2 infection rate from infected feces and urine. The World Health Organization has recommended the use of ultraviolet radiation (UV), disinfection, and filtration for wastewater contaminated with SARS-CoV-2, processes also common in wastewater treatment facilities. This article discusses these strategies referencing studies performed with surrogate viruses and shows that SARS-CoV-2 treatment can be complicated due to the interference from other aqueous chemical and physical factors. Considering that COVID-19 is not the first and certainly not the last pandemic, it is imperative to develop an effective multitreatment strategy for wastewater contaminated with contagious viruses and, preferably, those that are compatible with current wastewater treatment methods.

Lack of evidence for infectious SARS-CoV-2 in feces and sewage

The SARS-CoV-2 can be excreted in feces and can reach sewage systems. Determining the presence of infective viral particles in feces and sewage is necessary to take adequate control measures and to elucidate new routes of transmission. Here, we have developed a sample concentration methodology that allows us to maintain viral infectivity. Feces of COVID-19 patients and wastewater samples have been analyzed both by molecular methods and cell culture. Our results show no evidence of infective viral particles, suggesting that fecal–oral transmission is not a primary route. However, larger-scale efforts are needed, especially with the emergence of new viral variants.

Uncertainties in estimating SARS-CoV-2 prevalence by wastewater-based epidemiology

Wastewater-based epidemiology (WBE) is a promising approach for estimating population-wide COVID-19 prevalence through detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in wastewater. However, various methodological challenges associated with WBE would affect the accuracy of prevalence estimation. To date, the overall uncertainty of WBE and the impact of each step on the prevalence estimation are largely unknown. This study divided the WBE approach into five steps (i.e., virus shedding; in-sewer transportation; sampling and storage; analysis of SARS-CoV-2 RNA concentration in wastewater; back-estimation) and further summarized and quantified the uncertainties associated with each step through a systematic review. Although the shedding of SARS-CoV-2 RNA varied greatly between COVID-19 positive patients, with more than 10 infected persons in the catchment area, the uncertainty caused by the excretion rate became limited for the prevalence estimation. Using a high-frequency flow-proportional sampling and estimating the prevalence through actual water usage data significantly reduced the overall uncertainties to around 20-40% (relative standard deviation, RSD). And under such a scenario, the analytical uncertainty of SARS-CoV-2 RNA in wastewater was the dominant factor. This highlights the importance of using surrogate viruses as internal or external standards during the wastewater analysis, and the need for further improvement on analytical approaches to minimize the analytical uncertainty. This study supports the application of WBE as a complementary surveillance strategy for monitoring COVID-19 prevalence and provides methodological improvements and suggestions to enhance the reliability for future studies.

Lessons from countries implementing find, test, trace, isolation and support policies in the rapid response of the COVID-19 pandemic: a systematic review

OBJECTIVE

To systematically learn lessons from the experiences of countries implementing find, test, trace, isolate, support (FTTIS) in the first wave of the COVID-19 pandemic.

DESIGN, DATA SOURCES AND ELIGIBILITY CRITERIA

We searched MEDLINE (PubMed), Cochrane Library, SCOPUS and JSTOR, initially between 31 May 2019 and 21 January 2021. Research articles and reviews on the use of contact tracing, testing, self-isolation and quarantine for COVID-19 management were included in the review.

DATA EXTRACTION AND SYNTHESIS

We extracted information including study objective, design, methods, main findings and implications. These were tabulated and a narrative synthesis was undertaken given the diverse research designs, methods and implications.

RESULTS

We identified and included 118 eligible studies. We identified the core elements of an effective find, test, trace, isolate, support (FTTIS) system needed to interrupt the spread of a novel infectious disease, where treatment or vaccination was not yet available, as pertained in the initial stages of the COVID-19 pandemic. We report methods used to shorten case finding time, improve accuracy and efficiency of tests, coordinate stakeholders and actors involved in an FTTIS system, support individuals isolating and make appropriate use of digital tools.

CONCLUSIONS

We identified in our systematic review the key components of an FTTIS system. These include border controls, restricted entry, inbound traveller quarantine and comprehensive case finding; repeated testing to minimise false diagnoses and pooled testing in resource-limited circumstances; extended quarantine period and the use of digital tools for contact tracing and self-isolation. Support for mental or physical health and livelihoods is needed for individuals undergoing self-isolation/quarantine. An integrated system with rolling-wave planning can best use effective FTTIS tools to respond to the fast-changing COVID-19 pandemic. Results of the review may inform countries considering implementing these measures.

Sampling methods and assays applied in SARS-CoV-2 exposure assessment

The SARS-CoV-2 exposure assessment is critical to implement control measures and guarantee safety of patients and workers from different occupational environments. The aim of this review article was to identify methodologies applied for SARS-CoV-2 sampling and analyses in environmental samples in different occupational and indoor environments. This study reports the search of available data published between May 29th 2020 and November 1st 2020. The search strategy used allowed the identification of 48 papers that comply with selected inclusion and exclusion criteria. The most described indoor environment consisted of health care facilities. From all the analyzed studies, 34 sampled surfaces, 27 sampled air (impactors and impingers being the most used), and 9 sampled water. All studies were based on molecular detection by qPCR of viral RNA extracted from collected samples. SARS-CoV-2 was detected in 44 out of the 48 studies. The results suggest that the sampling approach should include both active and passive sampling methods in order to overcome each method limitations. Concerning the assays used, although most studies were based on qPCR detection, the fact that the digital PCR technique allows SARS-CoV-2 detection at lower concentrations, indicates that this should be the chosen method for future detection studies.

Wastewater-Based Epidemiology for Managing the COVID-19 Pandemic

SARS-CoV-2 is shed by COVID-19 patients and can be detected in wastewater. Thus, testing wastewater for the virus provides a depiction of disease prevalence in a community. Virus concentration data can be utilized to monitor infection trends, identify hot spots, and inform decision makers regarding reopening efforts and directing resources. This perspective aims to shed light on the current situation relating to SARS-CoV-2 in the wastewater system and the opportunity to utilize wastewater to collect useful epidemiological data. First, the survivability of SARS-CoV-2 in different water matrices is examined through the lens of surrogate viruses. Second, the effect of wastewater treatment processes on SARS-CoV-2 is investigated. Current standards for sufficient reduction of the virus and the risk of exposure that arises at each stage in the wastewater treatment process are discussed. Third, the immense potential of wastewater-based epidemiology (WBE) for managing the ongoing COVID-19 pandemic is analyzed. Studies that have tested wastewater or sludge for SARS-CoV-2 are discussed, and results are tabulated. Lastly, the current limitations of WBE and opportunities of future research are explored. Using the wealth of knowledge that the scientific community now has about WBE, wastewater testing should be considered by regional governments and private institutions.

Role of the Healthcare Surface Environment in Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Transmission and Potential Control Measures

The healthcare environment serves as one of the possible routes of transmission of epidemiologically important pathogens, but the role of the contaminated environment on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission remains unclear. We reviewed survival, contamination, and transmission of SARS-CoV-2 via environmental surfaces and shared medical devices as well as environmental disinfection of SARS-CoV-2 in healthcare settings. Coronaviruses, including SARS-CoV-2, have been demonstrated to survive for hours to days on environmental surfaces depending on experimental conditions. The healthcare environment is frequently contaminated with SARS-CoV-2 RNA in most studies but without evidence of viable virus. Although direct exposure to respiratory droplets is the main transmission route of SARS-CoV-2, the contaminated healthcare environment can potentially result in transmission of SARS-CoV-2 as described with other coronaviruses such as SARS and Middle East respiratory syndrome coronaviruses. It is important to improve thoroughness of cleaning/disinfection practices in healthcare facilities and select effective disinfectants to decontaminate inanimate surfaces and shared patient care items.

SARS-CoV-2 in hospital indoor environments is predominantly non-infectious

Background

The ongoing SARS-CoV-2 pandemic has spread rapidly worldwide and disease prevention is more important than ever. In the absence of a vaccine, knowledge of the transmission routes and risk areas of infection remain the most important existing tools to prevent further spread.

Methods

Here we investigated the presence of the SARS-CoV-2 virus in the hospital environment at the Uppsala University Hospital Infectious Disease ward by RT-qPCR and determined the infectivity of the detected virus in vitro on Vero E6 cells.

Results

SARS-CoV-2 RNA was detected in several areas, although attempts to infect Vero E6 cells with positive samples were unsuccessful. However, RNase A treatment of positive samples prior to RNA extraction did not degrade viral RNA, indicating the presence of SARS-CoV-2 nucleocapsids or complete virus particles protecting the RNA as opposed to free viral RNA.

Conclusion

Our results show that even in places where a moderate concentration (Ct values between 30 and 38) of SARS-CoV-2 RNA was found; no infectious virus could be detected. This suggests that the SARS-CoV-2 virus in the hospital environment subsides in two states; as infectious and as non-infectious. Future work should investigate the reasons for the non-infectivity of SARS-CoV-2 virions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12985-021-01556-6.

Community structure of environmental microorganisms associated with COVID-19 affected patients

To clarify the characteristics and distribution of hospital environmental microbiome associated with confirmed COVID-19 patients. Environmental samples with varying degrees of contamination which were associated with confirmed COVID-19 patients were collected, including 13 aerosol samples collected near eight patients in different wards, five swabs from one patient's skin and his personal belongings, and two swabs from the surface of positive pressure respiratory protective hood and the face shield from a physician who had close contact with one patient. Metagenomic next-generation sequencing (mNGS) was used to analyze the composition of the microbiome. One of the aerosol samples (near patient 4) was detected positive for COVID-19, and others were all negative. The environmental samples collected in different wards possessed protean compositions and community structures, the dominant genera including Pseudomonas, Corynebacterium, Neisseria, Staphylococcus, Acinetobacter, and Cutibacterium. Top 10 of genera accounted for more than 76.72%. Genera abundance and proportion of human microbes and pathogens radiated outward from the patient, while the percentage of environmental microbes increased. The abundance of the pathogenic microorganism of medical supplies is significantly higher than other surface samples. The microbial compositions of the aerosol collected samples nearby the patients were mostly similar to those from the surfaces of the patient's skin and personal belongings, but the abundance varied greatly. The positive rate of COVID-19 RNA detected from aerosol around patients in general wards was quite low. The ward environment was predominantly inhabited by species closely related to admitted patients. The spread of hospital microorganisms via aerosol was influenced by the patients' activity.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10453-021-09708-5.

Microscopic Observation of SARS-Like Particles in RT-qPCR SARS-CoV-2 Positive Sewage Samples

The ongoing outbreak of novel coronavirus pneumonia (COVID-19) caused by SARS-CoV-2 infection has spread rapidly worldwide. The major transmission routes of SARS-CoV-2 are recognised as inhalation of aerosol/droplets and person-to-person contact. However, some studies have demonstrated that live SARS-CoV-2 can be isolated from the faeces and urine of infected patients, which can then enter the wastewater system. The currently available evidence indicates that the viral RNA present in wastewater may become a potential source of epidemiological data. However, to investigate whether wastewater may present a risk to humans such as sewage workers, we investigated whether intact particles of SARS-CoV-2 were observable and whether it was possible to isolate the virus in wastewater. Using a correlative strategy of light microscopy and electron microscopy (CLEM), we demonstrated the presence of intact and degraded SARS-like particles in RT-qPCR SARS-CoV-2-positive sewage sample collected in the city of Marseille. However, the viral infectivity assessment of SARS-CoV-2 in the wastewater was inconclusive, due to the presence of other viruses known to be highly resistant in the environment such as enteroviruses, rhinoviruses, and adenoviruses. Although the survival and the infectious risk of SARS-CoV-2 in wastewater cannot be excluded from our study, additional work may be required to investigate the stability, viability, fate, and decay mechanisms of SARS-CoV-2 thoroughly in wastewater.

Detection of SARS-CoV-2 RNA on public surfaces in a densely populated urban area of Brazil: A potential tool for monitoring the circulation of infected patients

The world is experiencing the worst global health crisis in recent decades since December/2019 due to a new pandemic coronavirus. The COVID-19 disease, caused by SARS-CoV-2, has resulted in more than 30 million cases and 950 thousand deaths worldwide as of September 21, 2020. Determining the extent of the virus on public surfaces is critical for understanding the potential risk of infection in these areas. In this study, we investigated the presence of SARS-CoV-2 RNA on public surfaces in a densely populated urban area in Brazil. Forty-nine of 933 samples tested positive (5.25%) for SARS-CoV-2 RNA, including samples collected from distinct material surfaces, including metal and concrete, and distinct places, mainly around hospital care units and public squares. Our data indicated the contamination of public surfaces by SARS-CoV-2, suggesting the circulation of infected patients and the risk of infection for the population. Constant monitoring of the virus in urban areas is required as a strategy to fight the pandemic and prevent further infections.

Thermal discomfort in healthcare workers during the COVID-19 pandemic

INTRODUCTION

Due to the COVID-19 pandemic, healthcare workers are now required to use additional personal protective equipment (PPEs) to protect themselves against the virus. That led to an increased clothing insulation which is negatively affecting the perceived healthcare workers' thermal sensation.

OBJECTIVES

While demonstrating through software simulations the potential level of thermal discomfort healthcare workers involved in the COVID-19 emergency can be subjected to, this work aims at identifying measures to improve thermal sensation perception and acceptable thermal conditions for medical personnel.

METHODS

After having obtained the insulation values of individual clothing used by staff during COVID-19 emergency through the use of a thermal well-being evaluation software, the Fanger indexes (PMV - Predicted Mean Vote and PPD - Predicted Percentage of Dissatisfied) were calculated in order to estimate staff satisfaction to microclimatic conditions.

RESULTS

The use of COVID-19 additional PPEs with an air temperature equal to 22 °C (normally considered optimal) brings the PMV index equal to 0.6, which corresponds to 11.8 % being unsatisfied (PPD) due to perceived heat.

DISCUSSION

The use of additional protective devices significantly increases the clothing insulation level, facilitating the onset of conditions of thermal discomfort in the health workers. Workers engaged in the execution of nasopharyngeal swabs were most affected by the summer weather conditions and certainly represent the most critical category, for which it would be recommended to implement a higher turnover of service to reduce individual exposure time and consequent discomfort.

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.