Occurrences of similar viral diversity in campus wastewater and reclaimed water of a university dormitory.

Water reuse from wastewater sources still remain some critical safety concerns associated with treacherous contaminants like pathogenic viruses. In this study, viral diversities in campus wastewater (CWW) and its reclaimed water (RCW) recycled for toilet flushing and garden irrigation of a university dormitory were assessed using metagenomic sequencing for acquisition of more background data. Results suggested majority (>80%) of gene sequences within assembled contigs predicted by open reading frame (ORF) finder were no-hit yet believed to be novel/unrevealed viral genomic information whereas hits matched bacteriophages (i.e., mainly Myoviridae, Podoviridae, and Siphoviridae families) were predominant in both CWW and RCW samples. Moreover, few pathogenic viruses (<1%) related to infections of human skin (e.g., Molluscum contagiosum virus, MCV), digestion system (e.g., hepatitis C virus, HCV), and gastrointestinal tract (e.g., human norovirus, HuNoV) were also noticed raising safety concerns about application of reclaimed waters. Low-affinity interactions of particular viral exterior proteins (e.g., envelope glycoproteins or spike proteins) for disinfectant ligand (e.g., chlorite) elucidated treatment limitations of current sewage processing systems even with membrane bioreactor and disinfectant contactor. Revolutionary disinfection approaches together with routine monitoring and new regulations are prerequisite to secure pathogen-correlated water quality for safer reuse of reclaimed waters.

An isotope dilution mass spectrometry assay to track Norovirus-like particles in vaccine process intermediates by quantifying capsid protein VP1.

The coronavirus disease (COVID-19) pandemic shows the rapid pace at which vaccine development can occur which highlights the need for more fast and efficient analytical methodologies to track and characterize candidate vaccines during manufacturing and purification processes. The candidate vaccine in this work comprises plant-derived Norovirus-like particles (NVLPs) which are structures that mimic the virus but lack any infectious genetic material. Presented here is a liquid chromatography-tandem mass spectrometry (LC-MS/MS) methodology for the quantification of viral protein VP1, the main component of the NVLPs in this study. It combines isotope dilution mass spectrometry (IDMS) with multiple reaction monitoring (MRM) to quantify targeted peptides in process intermediates. Multiple MRM transitions (precursor/product ion pairs) for VP1 peptides were tested with varying MS source conditions and collision energies. Final parameter selection for quantification includes three peptides with two MRM transitions each offering maximum detection sensitivity under optimized MS conditions. For quantification, a known concentration of the isotopically labeled version of the peptides to be quantified was added into working standard solutions to serve as an internal standard (IS); calibration curves were generated for concentration of native peptide vs. the peak area ratio of native-to-isotope labeled peptide. VP1 peptides in samples were quantified with labeled versions of the peptides added at the same level as that of the standards. Peptides were quantified with limit of detection (LOD) as low as 1.0 fmol µL-1 and limit of quantitation (LOQ) as low as 2.5 fmol µL-1. NVLP preparations spiked with known quantities of either native peptides or drug substance (DS) comprising assembled NVLPs produced recoveries indicative of minimal matrix effects. Overall, we report a fast, specific, selective, and sensitive LC-MS/MS strategy to track NVLPs through the purification steps of the DS of a Norovirus candidate vaccine. To the best of our knowledge, this is the first application of an IDMS method to track virus-like particles (VLPs) produced in plants as well as measurements performed with VP1, a Norovirus capsid protein.

Rapid Virucidal Activity of Japanese Saxifraga Species-Derived Condensed Tannins against SARS-CoV-2, Influenza A Virus, and Human Norovirus Surrogate Viruses.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A virus (IAV), and norovirus are global threats to human health. The application of effective virucidal agents, which contribute to the inactivation of viruses on hands and environmental surfaces, is important to facilitate robust virus infection control measures. Naturally derived virucidal disinfectants have attracted attention owing to their safety and eco-friendly properties. In this study, we showed that multiple Japanese Saxifraga species-derived fractions demonstrated rapid, potent virucidal activity against the SARS-CoV-2 ancestral strain and multiple variant strains, IAV, and two human norovirus surrogates: feline calicivirus (FCV) and murine norovirus (MNV). Condensed tannins were identified as active chemical constituents that play a central role in the virucidal activities of these fractions. At a concentration of 25 µg/mL, the purified condensed tannin fraction Sst-2R induced significant reductions in the viral titers of the SARS-CoV-2 ancestral strain, IAV, and FCV (reductions of ≥3.13, ≥3.00, and 2.50 log10 50% tissue culture infective doses [TCID50]/mL, respectively) within 10 s of reaction time. Furthermore, at a concentration of 100 µg/mL, Sst-2R induced a reduction of 1.75 log10 TCID50/mL in the viral titers of MNV within 1 min. Western blotting and transmission electron microscopy analyses revealed that Sst-2R produced structural abnormalities in viral structural proteins and envelopes, resulting in the destruction of viral particles. Furthermore, Saxifraga species-derived fraction-containing cream showed virucidal activity against multiple viruses within 10 min. Our findings indicate that Saxifraga species-derived fractions containing condensed tannins can be used as disinfectants against multiple viruses on hands and environmental surfaces. IMPORTANCE SARS-CoV-2, IAV, and norovirus are highly contagious pathogens. The use of naturally derived components as novel virucidal/antiviral agents is currently attracting attention. We showed that fractions from extracts of Saxifraga species, in the form of a solution as well as a cream, exerted potent, rapid virucidal activities against SARS-CoV-2, IAV, and surrogates of human norovirus. Condensed tannins were found to play a central role in this activity. The in vitro cytotoxicity of the purified condensed tannin fraction at a concentration that exhibited some extent of virucidal activity was lower than that of 70% ethanol or 2,000 ppm sodium hypochlorite solution, which are popular virucidal disinfectants. Our study suggests that Saxifraga species-derived fractions containing condensed tannins can be used on hands and environmental surfaces as safe virucidal agents against multiple viruses.

Predicting norovirus and rotavirus resurgence in the United States following the COVID-19 pandemic: a mathematical modelling study.

BACKGROUND: To reduce the burden from the COVID-19 pandemic in the United States, federal and state local governments implemented restrictions such as limitations on gatherings, restaurant dining, and travel, and recommended non-pharmaceutical interventions including physical distancing, mask-wearing, surface disinfection, and increased hand hygiene. Resulting behavioral changes impacted other infectious diseases including enteropathogens such as norovirus and rotavirus, which had fairly regular seasonal patterns prior to the COVID-19 pandemic. The study objective was to project future incidence of norovirus and rotavirus gastroenteritis as contacts resumed and other NPIs are relaxed. METHODS: We fitted compartmental mathematical models to pre-pandemic U.S. surveillance data (2012-2019) for norovirus and rotavirus using maximum likelihood estimation. Then, we projected incidence for 2022-2030 under scenarios where the number of contacts a person has per day varies from70%, 80%, 90%, and full resumption (100%) of pre-pandemic levels. RESULTS: We found that the population susceptibility to both viruses increased between March 2020 and November 2021. The 70-90% contact resumption scenarios led to lower incidence than observed pre-pandemic for both viruses. However, we found a greater than two-fold increase in community incidence relative to the pre-pandemic period under the 100% contact scenarios for both viruses. With rotavirus, for which population immunity is driven partially by vaccination, patterns settled into a new steady state quickly in 2022 under the 70-90% scenarios. For norovirus, for which immunity is relatively short-lasting and only acquired through infection, surged under the 100% contact scenario projection. CONCLUSIONS: These results, which quantify the consequences of population susceptibility build-up, can help public health agencies prepare for potential resurgence of enteric viruses.

Optimization and performance evaluation of an automated filtration method for the recovery of SARS-CoV-2 and other viruses in wastewater.

A rapid virus concentration method is needed to get high throughput. Reliable results of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) detection in wastewater are necessary for applications in wastewater-based epidemiology. In this study, an automated filtration method using a concentrating pipette (CP Select; Innovaprep) was applied to detect SARS-CoV-2 in wastewater samples with several modifications to increase its sensitivity and throughput. The performance of the CP Select method was compared to other concentration methods (polyethylene glycol precipitation and direct capture using silica column) to evaluate its applicability to SARS-CoV-2 detection in wastewater. SARS-CoV-2 RNA was successfully detected in six of eight wastewater samples using the CP Select method, whereas other methods could detect SARS-CoV-2 RNA in all wastewater samples. Enteric viruses, such as noroviruses of genogroups I (NoVs-GI) and II (NoVs-GII) and enteroviruses, were tested, resulting in 100 % NoVs-GII detection using all concentration methods. As for NoVs-GI and enteroviruses, all methods gave comparable number of detected samples in wastewater samples. This study showed that the optimized CP Select method was less sensitive in SARS-CoV-2 detection in wastewater than other methods, whereas all methods were applicable to detect or recover other viruses in wastewater.

Genotype Diversity of Enteric Viruses in Wastewater Amid the COVID-19 Pandemic.

Viruses remain the leading cause of acute gastroenteritis (AGE) worldwide. Recently, we reported the abundance of AGE viruses in raw sewage water (SW) during the COVID-19 pandemic, when viral AGE patients decreased dramatically in clinics. Since clinical samples were not reflecting the actual state, it remained important to determine the circulating strains in the SW for preparedness against impending outbreaks. Raw SW was collected from a sewage treatment plant in Japan from August 2018 to March 2022, concentrated by polyethylene-glycol-precipitation method, and investigated for major gastroenteritis viruses by RT-PCR. Genotypes and evolutionary relationships were evaluated through sequence-based analyses. Major AGE viruses like rotavirus A (RVA), norovirus (NoV) GI and GII, and astrovirus (AstV) increased sharply (10-20%) in SW during the COVID-19 pandemic, though some AGE viruses like sapovirus (SV), adenovirus (AdV), and enterovirus (EV) decreased slightly (3-10%). The prevalence remained top in the winter. Importantly, several strains, including G1 and G3 of RVA, GI.1 and GII.2 of NoV, GI.1 of SV, MLB1 of AstV, and F41 of AdV, either emerged or increased amid the pandemic, suggesting that the normal phenomenon of genotype changing remained active over this time. This study crucially presents the molecular characteristics of circulating AGE viruses, explaining the importance of SW investigation during the pandemic when a clinical investigation may not produce the complete scenario.

Childcare and School Acute Gastroenteritis Outbreaks: 2009-2020.

OBJECTIVES: Acute gastroenteritis (AGE) outbreaks commonly occur in congregate settings, including schools and childcare facilities. These outbreaks disrupt institutions, causing absences and temporary facility closures. This study analyzed the epidemiology of school and childcare AGE outbreaks in the United States. METHODS: We analyzed AGE outbreaks occurring in kindergarten to grade 12 schools and childcare facilities reported via the National Outbreak Reporting System in the United States from 2009 to 2019 and compared this information to 2020 data. Outbreak and case characteristics were compared using the Kruskal-Wallis rank sum test, χ2 goodness-of-fit test, and Fisher exact test. RESULTS: From 2009 to 2019, there were 2623 school, 1972 childcare, and 38 school and childcare outbreaks. School outbreaks were larger (median, 29 cases) than childcare outbreaks (median, 10 cases). Childcare outbreaks were longer (median, 15 days) than school outbreaks (median, 9 days). Norovirus (2383 outbreaks; 110 190 illnesses) and Shigella spp. (756 outbreaks; 9123 illnesses) were the most reported etiologies. Norovirus was the leading etiology in schools; norovirus and Shigella spp. were dominant etiologies in childcare centers. Most (85.7%) outbreaks were spread via person-to-person contact. In 2020, 123 outbreaks were reported, 85% in the first quarter. CONCLUSIONS: Schools and childcare centers are common AGE outbreak settings in the United States. Most outbreaks were caused by norovirus and Shigella spp. and spread via person-to-person transmission. Fewer outbreaks were reported in 2020 from the COVID-19 pandemic. Prevention and control efforts should focus on interrupting transmission, including environmental disinfection, proper handwashing, safe diapering, and exclusion of ill persons.

Reduced norovirus epidemic follows increased sales of hand hygiene products in Japan, 2020-2021.

During the recent emergence of COVID-19, an increased practice of hand hygiene coincided with the reduced incidence of the norovirus epidemic in Japan, which is similar to experience with the pandemic flu in 2009. We investigated the relationship between the sales of hand hygiene products, including liquid hand soap and alcohol-based hand sanitizer, and the trend of norovirus epidemic. We used national gastroenteritis surveillance data across Japan in 2020 and 2021 and compared the base statistics of incidence of these two years with the average of the previous 10 years (2010-2019). We calculated the correlations (Spearman's Rho) between monthly sales of hand hygiene products and monthly norovirus cases and fitted them to a regression model. In 2020, there was no epidemic, and the incidence peak was the lowest in recent norovirus epidemics. In 2021, the incidence peak was delayed for five weeks to the usual epidemic seasons. Correlation coefficients between monthly sales of liquid hand soap and skin antiseptics and norovirus incidence showed a significantly negative correlation (Spearman's Rho = -0.88 and p = 0.002 for liquid hand soap; Spearman's Rho = -0.81 and p = 0.007 for skin antiseptics). Exponential regression models were fitted between the sales of each hand hygiene product and norovirus cases, respectively. The results suggest hand hygiene using these products is a potentially useful prevention method against norovirus epidemics. Effective ways of hand hygiene for increasing the prevention of norovirus should therefore be studied.

Emergent variant modeling of the serological repertoire to norovirus in young children.

Human norovirus is the leading cause of acute gastroenteritis. Young children and the elderly bear the greatest burden of disease, representing more than 200,000 deaths annually. Infection prevalence peaks at younger than 2 years and is driven by novel GII.4 variants that emerge and spread globally. Using a surrogate neutralization assay, we characterize the evolution of the serological neutralizing antibody (nAb) landscape in young children as they transition between sequential GII.4 pandemic variants. Following upsurge of the replacement variant, antigenic cartography illustrates remodeling of the nAb landscape to the new variant accompanied by improved nAb titer. However, nAb relative avidity remains focused on the preceding variant. These data support immune imprinting as a mechanism of immune evasion and GII.4 virus persistence across a population. Understanding the complexities of immunity to rapidly evolving and co-circulating viral variants, like those of norovirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV2), and dengue viruses, will fundamentally inform vaccine design for emerging pathogens.

Expanding the Pathogen Panel in Wastewater Epidemiology to Influenza and Norovirus.

Since the start of the 2019 pandemic, wastewater-based epidemiology (WBE) has proven to be a valuable tool for monitoring the prevalence of SARS-CoV-2. With methods and infrastructure being settled, it is time to expand the potential of this tool to a wider range of pathogens. We used over 500 archived RNA extracts from a WBE program for SARS-CoV-2 surveillance to monitor wastewater from 11 treatment plants for the presence of influenza and norovirus twice a week during the winter season of 2021/2022. Extracts were analyzed via digital PCR for influenza A, influenza B, norovirus GI, and norovirus GII. Resulting viral loads were normalized on the basis of NH4-N. Our results show a good applicability of ammonia-normalization to compare different wastewater treatment plants. Extracts originally prepared for SARS-CoV-2 surveillance contained sufficient genomic material to monitor influenza A, norovirus GI, and GII. Viral loads of influenza A and norovirus GII in wastewater correlated with numbers from infected inpatients. Further, SARS-CoV-2 related non-pharmaceutical interventions affected subsequent changes in viral loads of both pathogens. In conclusion, the expansion of existing WBE surveillance programs to include additional pathogens besides SARS-CoV-2 offers a valuable and cost-efficient possibility to gain public health information.

Advanced simulations and screening to repurposing a 3C protease inhibitor against the rupintrivir-resistant human norovirus-induced gastroenteritis.

Human norovirus (HuNoV) causes acute viral gastroenteritis in all age groups, and dehydration and severe diarrhea in the elderly. The World Health Organization reports ∼1.45 million deaths from acute gastroenteritis annually in the world. Rupintrivir, an inhibitory medicine against the human rhinovirus C3 protease, has been reported to inhibit HuNoV 3C protease. However, several HuNoV 3C protease mutations have been revealed to reduce the susceptibility of HuNoV to rupintrivir. The structural details behind rupintrivir-resistance of these single-point mutations (A105V and I109V) are not still clear. Hence, in this study, a combination of computational techniques were used to determine the rupintrivir-resistance mechanism and to propose an inhibitor against wild-type and mutant HuNoV 3C protease through structure-based virtual screening. Dynamic structural results indicated the unstable binding of rupintrivir at the cleft binding site of the wild-type and mutant 3C proteases, leading to its detachment. Our findings presented that the domain II of the HuNoV 3C protease had a critical role in binding of inhibitory molecules. Binding energy computations, steered molecular dynamics and umbrella sampling simulations confirmed that amentoflavone, the novel suggested inhibitor, strongly binds to the cleft site of all protease models and has a good structural stability in the complex system along the molecular dynamic simulations. Our in silico study proposed the selected compound as a potential inhibitor against the HuNoV 3C protease. However, additional experimental and clinical studies are required to corroborate the therapeutic efficacy of the compound.

Antimicrobial efficacy and inactivation kinetics of a novel LED-based UV-irradiation technology.

BACKGROUND: Ultraviolet (UV)-light-emitting diodes (UV-LEDs) are energy efficient and of special interest for the inactivation of micro-organisms. In the context of the coronavirus disease 2019 pandemic, novel UV technologies can offer a powerful alternative for effective infection prevention and control. METHODS: This study assessed the antimicrobial efficacy of UV-C LEDs on Escherichia coli, Pseudomonas fluorescens and Listeria innocua, as well as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), human immunodeficiency virus-1 (HIV-1) and murine norovirus (MNV), dried on inanimate surfaces, based on European Standard EN 17272. RESULTS: This study found 90% inactivation rates for the tested bacteria at mean UV-C doses, averaged over all three investigated UV-C wavelengths, of 1.7 mJ/cm2 for E. coli, 1.9 mJ/cm2 for P. fluorescens and 1.5 mJ/cm2 for L. innocua. For the tested viruses, UV doses <15 mJ/cm2 resulted in 90% inactivation at wavelengths of 255 and 265 nm. Exposure of viruses to longer UV wavelengths, such as 275 and 285 nm, required much higher doses (up to 120 mJ/cm2) for inactivation. Regarding inactivation, non-enveloped MNV required much higher UV doses for all tested wavelengths compared with SARS-CoV-2 or HIV-1. CONCLUSION: Overall, the results support the use of LEDs emitting at shorter wavelengths of the UV-C spectrum to inactivate bacteria as well as enveloped and non-enveloped viruses by exposure to the appropriate UV dose. However, low availability and excessive production costs of shortwave UV-C LEDs restricts implementation at present, and supports the use of longwave UV-C LEDs in combination with higher irradiation doses.

Norovirus, Hepatitis A and SARS-CoV-2 surveillance within Chilean rural wastewater treatment plants based on different biological treatment typologies.

During the COVID-19 pandemic, wastewater from WWTPs became an interesting source of epidemiological surveillance. However, there is uncertainty about the influence of treatment type on virus removal. The aim of this study was to assess viral surveillance within wastewater treatment plants (WWTPs) based on different biological treatments. Seasonal monitoring (autumn-winter and spring-summer) was conducted in 10 Chilean rural WWTPs, which were based on activated sludge, aerated lagoons, bio-discs, constructed wetlands, vermifilters and mixed systems. Viruses were measured (influent/effluent) by the RT-qPCR technique, using a commercial kit for SARS-CoV-2, NoV GI, NoV GII, and HAV. The detection of SARS-CoV-2 viral variants by genotyping was performed using SARS-CoV-2 Mutation Assays (ThermoFisher Scientific, USA). JC polyomavirus detection (control), as well as a qPCR technique. Results showed that SARS-CoV-2, NoV GI and GII were detected in influents at values between <5 and 462, 0 to 28, and 0 to 75 GC/mL, respectively. HAV was not detected among the studied WWTPs. The monitored WWTPs removed these viruses at percentages between 0 and 100 %. WWTPs based on activated sludge with bio-discs demonstrated to be the most efficient at removing SARS-CoV-2 (up to 98 %) and NoV GI and GII (100 %). Meanwhile, bio-discs technologies were the least efficient for viral removal, due to biofilm detachment, which could also adsorb viral aggregates. A correlation analysis established that solids, pH, and temperature are the most influential parameters in viral removal. Wastewater-based surveillance at WWTP allowed for the detection of Omicron before the Chilean health authorities notified its presence in the population. In addition, surveillance of viruses and other microorganisms could help assess the potential public health risk of wastewater recycling.

Assessing the Removal Efficiency of Murine Norovirus 1, Hepatitis A Virus, and Human Coronavirus 229E on Dish Surfaces Through General Wash Program of Household Dishwasher.

The performance of dishwashers in removing live viruses is an important informative value in practical applications. Since foodborne viruses are present in contaminated food surfaces and water environments. Insufficient washing of dishes typically makes a carrier of foodborne viruses. Dishwashers have shown excellent performance in removing bacterial pathogens, but very limited reports related to eliminate foodborne viruses on contaminated dish surfaces. Here, murine norovirus 1 (MNV-1), hepatitis A virus (HAV), and human coronavirus 229E (HCoV-229E) were experimentally inoculated on the dish surfaces (plate, rice bowl, and soup bowl). Plaque assay, 50% tissue culture infectious dose (TCID50), and real-time quantitative polymerase chain reaction (RT-qPCR) were conducted to determine their removal efficiency of them through the general wash program of household dishwashers. Using titration assay, MNV-1 and HAV were reduced by 7.44 and 6.57 log10 PFU/dish, and HCoV-229E was reduced by 6.43 log10 TCID50/dish through the general wash program, achieving a ≥ 99.999% reduction, respectively. Additionally, RT-qPCR results revealed that viral RNA of MNV-1 and HCoV-229E reduced 5.02 and 4.54 log10 genome copies/dish; in contrast, HAV was not detected on any dish surfaces. This study confirmed the performance of household dishwashers in removing pathogenic live viruses through the general wash program. However, residual viral RNA was not sufficiently removed. Further studies are needed to determine whether the viral RNA can be sufficiently removed using combination programs in household dishwashers.

Evaluation of two different concentration methods for surveillance of human viruses in sewage and their effects on SARS-CoV-2 sequencing.

During the current COVID-19 pandemic, wastewater-based epidemiology (WBE) emerged as a reliable strategy both as a surveillance method and a way to provide an overview of the SARS-CoV-2 variants circulating among the population. Our objective was to compare two different concentration methods, a well-established aluminum-based procedure (AP) and the commercially available Maxwell® RSC Enviro Wastewater TNA Kit (TNA) for human enteric virus, viral indicators and SARS-CoV-2 surveillance. Additionally, both concentration methods were analyzed for their impact on viral infectivity, and nucleic acids obtained from each method were also evaluated by massive sequencing for SARS-CoV-2. The percentage of SARS-CoV-2 positive samples using the AP method accounted to 100 %, 83.3 %, and 33.3 % depending on the target region while 100 % positivity for these same three target regions was reported using the TNA procedure. The concentrations of norovirus GI, norovirus GII and HEV using the TNA method were significantly greater than for the AP method while no differences were reported for rotavirus, astrovirus, crAssphage and PMMoV. Furthermore, TNA kit in combination with the Artic v4 primer scheme yields the best SARS-CoV-2 sequencing results. Regarding impact on infectivity, the concentration method used by the TNA kit showed near-complete lysis of viruses. Our results suggest that although the performance of the TNA kit was higher than that of the aluminum procedure, both methods are suitable for the analysis of enveloped and non-enveloped viruses in wastewater by molecular methods.

Virus contamination and infectivity in beach environment: Focus on sand and stranded material.

To assess the exposure of beachgoers to viruses, a study on seawater, sand, and beach-stranded material was carried out, searching for human viruses, fecal indicator organisms, and total fungi. Moreover, for the first time, the genome persistence and infectivity of two model viruses was studied in laboratory-spiked sand and seawater samples during a one-week experiment. Viral genome was detected in 13.6 % of the environmental samples, but it was not infectious (Human Adenovirus - HAdV, and enterovirus). Norovirus and SARS-CoV-2 were not detected. The most contaminated samples were from sand and close to riverine discharges. In lab-scale experiments, the infectivity of HAdV5 decreased by ~1.5-Log10 in a week, the one of Human Coronavirus-229E disappeared in <3 h in sand. The genome of both viruses persisted throughout the experiment. Our results confirm viral contamination of the beach and suggest HAdV as an index pathogen for beach monitoring and quantitative risk assessment.

Changes in norovirus incidence in Victoria, Australia, during the COVID-19 pandemic, 2020-2021.

There were 142 norovirus positive outbreaks in Victoria for the 2020-2021 calendar years; however, almost half of these (48.6%) occurred in Q1 (January-March) of 2021. For the two-year period, 69.0% of all norovirus positive outbreaks were in childcare settings, and the predominant genotype was GII.P16/GII.2 (64.9%) followed by GII.P31/GII.4_2012 (20.9%). Norovirus incidence was particularly low in 2020 (n = 26) and close to average in 2021 (n = 116), but genotype diversity was low in both years. With the thought that 2022 will approach a more normal aspect to socialising and travel, norovirus incidence in 2022 may be predicted to increase above typical levels.

Impact of COVID-19 Nonpharmaceutical Interventions on the Extent of Norovirus Contamination in Oyster Production Areas in Ireland during Winter 2020 to 2021.

ABSTRACT: A significant decrease in norovirus prevalence and concentration was observed in oyster production areas in Ireland during winter 2020 to 2021. Oyster production areas impacted by human wastewater discharges that had been undergoing norovirus surveillance since 2018 were investigated. Samples collected in the winter seasons of 2018 to 2019 and 2019 to 2020, prior to when the COVID-19 pandemic interventions were applied, showed a prevalence of 94.3 and 96.6%, respectively, and geometric mean concentrations of 533 and 323 genome copies per g, respectively. These values decreased significantly during the winter of 2020 to 2021 (prevalence of 63.2% and geometric concentration of below the limit of quantification), coinciding with the control measures to mitigate the transmission of severe acute respiratory syndrome coronavirus 2 of the genus Betacoronavirus. Divergence between norovirus GI and GII prevalence and concentrations was observed over the 3-year monitoring period. Norovirus GII was the dominant genogroup detected in winter 2020 to 2021, with over half of samples positive, although concentrations detected were significantly lower than prepandemic winters, with a geometric mean concentration of below the limit of quantification.

Of masks and methylene blue-The use of methylene blue photochemical treatment to decontaminate surgical masks contaminated with a tenacious small nonenveloped norovirus.

BACKGROUND: In the context of the SARS-CoV-2 pandemic, reuse of personal protective equipment, specifically that of medical face coverings, has been recommended. The reuse of these typically single-use only items necessitates procedures to inactivate contaminating human respiratory and gastrointestinal pathogens. We previously demonstrated decontamination of surgical masks and respirators contaminated with infectious SARS-CoV-2 and various animal coronaviruses via low concentration- and short exposure methylene blue photochemical treatment (10 µM methylene blue, 30 minutes of 12,500-lux red light or 50,000 lux white light exposure). METHODS: Here, we describe the adaptation of this protocol to the decontamination of a more resistant, non-enveloped gastrointestinal virus and demonstrate efficient photodynamic inactivation of murine norovirus, a human norovirus surrogate. RESULTS: Methylene blue photochemical treatment (100 µM methylene blue, 30 minutes of 12,500-lux red light exposure) of murine norovirus-contaminated masks reduced infectious viral titers by over four orders of magnitude on surgical mask surfaces. DISCUSSION AND CONCLUSIONS: Inactivation of a norovirus, the most difficult to inactivate of the respiratory and gastrointestinal human viruses, can predict the inactivation of any less resistant viral mask contaminant. The protocol developed here thus solidifies the position of methylene blue photochemical decontamination as an important tool in the package of practical pandemic preparedness.

Norovirus Intestinal Infection and Lewy Body Disease in an Older Patient with Acute Cognitive Impairment.

We present a case report on an older woman with unspecific symptoms and predominant long-term gastrointestinal disturbances, acute overall health deterioration with loss of autonomy for daily activities, and cognitive impairment. Autopsy revealed the presence of alpha-synuclein deposits spread into intestinal mucosa lesions, enteric plexuses, pelvic and retroperitoneal nerves and ganglia, and other organs as well as Lewy pathology in the central nervous system (CNS). Moreover, we isolated norovirus from the patient, indicating active infection in the colon and detected colocalization of norovirus and alpha-synuclein in different regions of the patient's brain. In view of this, we report a concomitant norovirus infection with synthesis of alpha-synuclein in the gastrointestinal mucosa and Lewy pathology in the CNS, which might support Braak's hypothesis about the pathogenic mechanisms underlying synucleinopathies.