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1.
J Infect Chemother ; 28(1): 67-72, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34635450

RESUMO

INTRODUCTION: Human norovirus (HuNoV) is a leading cause of infectious gastroenteritis. Since HuNoV shows resistance to alcohol, chlorine-based sanitizers are applied to decontaminate the virus on environmental surfaces. Chlorous acid water (CA) has been recently approved as a novel chlorine-based disinfectant categorized as a Type 2 OTC medicine in Japan. In this study, we aimed to evaluate the capability of CA to inactivate HuNoV. METHODS: HuNoV (genogroups GII.2 and GII.4) was exposed to the test disinfectants including CA and sodium hypochlorite (NaClO), and the residual RNA copy was measured by reverse transcription quantitative PCR (RT-qPCR) after pretreatment with RNase. In addition, the log10 reduction of HuNoV RNA copy number by CA and NaClO was compared in the presence of bovine serum albumin (BSA), sheep red blood cells (SRBC), polypeptone, meat extract or amino acids to evaluate the stability of these disinfectants under organic-matter-rich conditions. RESULTS: In the absence of organic substances, CA with 200 ppm free available chlorine provided >3.0 log10 reduction in the HuNoV RNA copy number within 5 min. Even under high organic matter load (0.3% each of BSA and SRBC or 0.5% polypeptone), 200 ppm CA achieved >3.0 log10 reduction in HuNoV RNA copy number while less than 1.0 log10 reduction was observed with 1,000 ppm sodium hypochlorite (NaClO) in the presence of 0.5% polypeptone. CA reacted with only cysteine, histidine and glutathione while NaClO reacted with all of the amino acids tested. CONCLUSIONS: CA is an effective disinfectant to inactivate HuNoV under organic-matter-rich conditions.


Assuntos
Desinfetantes , Norovirus , Animais , Cloretos , Cloro/farmacologia , Desinfetantes/farmacologia , Humanos , Ovinos , Água
2.
Talanta ; 237: 122896, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34736712

RESUMO

Noroviruses are the leading cause of acute gastroenteritis and food-borne diseases worldwide. Thus, a rapid, accurate, and easy-to-implement detection method for controlling infection and monitoring progression is urgently needed. In this study, we constructed a novel sandwich-type electrochemical biosensor integrated with two specific recognition elements (aptamer and peptide) for human norovirus (HuNoV). The electrochemical biosensor was fabricated using magnetic covalent organic framework/pillararene heterosupramolecular nanocomposites (MB@Apt@WP5A@Au@COF@Fe3O4) as the signal probes. The sensor showed high accuracy and selectivity. The detection method does not need the extraction and amplification of virus nucleic acid and has a short turn-around time. Intriguingly, the proposed biosensor had a limit of detection of 0.84 copy mL-1 for HuNoV, which was the highest sensitivity among published assays. The proposed biosensor showed higher sensitivity and accuracy compared with immunochromatographic assay in the detection of 98 clinical specimens. The biosensor was capable of determining the predominant infection strain of GII.4 and also GII.3 and achieved 74% selectivity for HuNoV GII group. This study provides a potential method for point-of-care testing and highlights the integrated utilization of Apt and peptide in sensor construction.


Assuntos
Técnicas Biossensoriais , Estruturas Metalorgânicas , Nanocompostos , Norovirus , Humanos , Imunoensaio
3.
BMC Med ; 19(1): 299, 2021 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-34753508

RESUMO

BACKGROUND: To reduce the coronavirus disease burden in England, along with many other countries, the government implemented a package of non-pharmaceutical interventions (NPIs) that have also impacted other transmissible infectious diseases such as norovirus. It is unclear what future norovirus disease incidence is likely to look like upon lifting these restrictions. METHODS: Here we use a mathematical model of norovirus fitted to community incidence data in England to project forward expected incidence based on contact surveys that have been collected throughout 2020-2021. RESULTS: We report that susceptibility to norovirus infection has likely increased between March 2020 and mid-2021. Depending upon assumptions of future contact patterns incidence of norovirus that is similar to pre-pandemic levels or an increase beyond what has been previously reported is likely to occur once restrictions are lifted. Should adult contact patterns return to 80% of pre-pandemic levels, the incidence of norovirus will be similar to previous years. If contact patterns return to pre-pandemic levels, there is a potential for the expected annual incidence to be up to 2-fold larger than in a typical year. The age-specific incidence is similar across all ages. CONCLUSIONS: Continued national surveillance for endemic diseases such as norovirus will be essential after NPIs are lifted to allow healthcare services to adequately prepare for a potential increase in cases and hospital pressures beyond what is typically experienced.


Assuntos
COVID-19 , Norovirus , Inglaterra/epidemiologia , Humanos , Modelos Teóricos , SARS-CoV-2
4.
BMC Genomics ; 22(1): 849, 2021 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-34819031

RESUMO

BACKGROUND: Genome assembly of viruses with high mutation rates, such as Norovirus and other RNA viruses, or from metagenome samples, poses a challenge for the scientific community due to the coexistence of several viral quasispecies and strains. Furthermore, there is no standard method for obtaining whole-genome sequences in non-related patients. After polyA RNA isolation and sequencing in eight patients with acute gastroenteritis, we evaluated two de Bruijn graph assemblers (SPAdes and MEGAHIT), combined with four different and common pre-assembly strategies, and compared those yielding whole genome Norovirus contigs. RESULTS: Reference-genome guided strategies with both host and target virus did not present any advantages compared to the assembly of non-filtered data in the case of SPAdes, and in the case of MEGAHIT, only host genome filtering presented improvements. MEGAHIT performed better than SPAdes in most samples, reaching complete genome sequences in most of them for all the strategies employed. Read binning with CD-HIT improved assembly when paired with different analysis strategies, and more notably in the case of SPAdes. CONCLUSIONS: Not all metagenome assemblies are equal and the choice in the workflow depends on the species studied and the prior steps to analysis. We may need different approaches even for samples treated equally due to the presence of high intra host variability. We tested and compared different workflows for the accurate assembly of Norovirus genomes and established their assembly capacities for this purpose.


Assuntos
Metagenoma , Norovirus , Algoritmos , Benchmarking , Humanos , Metagenômica , Norovirus/genética , Análise de Sequência , Análise de Sequência de DNA , Software
5.
Zhonghua Yu Fang Yi Xue Za Zhi ; 55(11): 1316-1320, 2021 Nov 06.
Artigo em Chinês | MEDLINE | ID: mdl-34749475

RESUMO

Objective: We aimed to analyze the the genotyping of norovirus infectious diarrhea epidemic in Songjiang district, Shanghai, and explored the experience in handling the epidemic to provide a scientific basis for formulating prevention and treatment strategies. Methods: The epidemiological data and related samples of 69 outbreaks of infectious diarrhea caused by norovirus was collected from 2017 to 2019 in Songjiang district, Shanghai. Sequencing and type identification were performed by the method of gene sequencing for the junction region of Norovirus ORF1 and ORF2. Results: From 2017 to 2019, 69 outbreaks of norovirus infections diarrhea were reported in Songjiang district, Shanghai. A total of 1 767 samples were tested, including 619 case samples (positive rate 19.9%), 343 practitioner samples (positive rate 1.1%), 505 environmental samples (positive rate 0.5%) and 300 food samples (not detected). 141 sequences were obtained, and the genotype analysis showed that the genotype that mainly caused infectious diarrhea in 2017 and 2018 was GII.P16-GII.2 (50.98%, 26/51). In 2019, the genotypes that mainly caused infectious diarrhea were GII.P16-GII.2 (13.73%, 7/51) and GII.Pe-GII.4 (9.80%, 5/51). Conclusion: The main genotype of the 69 outbreaks of nororirus infectious diarrhea epidemic in Songjiang district, Shanghai from 2017 to 2019 was GII.P16-GII.2, which showed obvious peaks in spring, autumn and winter. There were more infections in kindergartens and schools. The surveillance of norovirus infection should be strengthened.


Assuntos
Infecções por Caliciviridae , Gastroenterite , Norovirus , Infecções por Caliciviridae/epidemiologia , China/epidemiologia , Diarreia/epidemiologia , Surtos de Doenças , Gastroenterite/epidemiologia , Genótipo , Humanos , Norovirus/genética , Filogenia
6.
Zhongguo Dang Dai Er Ke Za Zhi ; 23(10): 1027-1032, 2021 Oct 15.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-34719418

RESUMO

OBJECTIVES: To study the molecular epidemiological characteristics of norovirus in children with acute gastroenteritis from 2017 to 2019. METHODS: A retrospective analysis was performed on the medical data of children with acute gastroenteritis who were admitted to Children's Hospital of Chongqing Medical University from January 2017 to December 2019. A total of 1 458 stool samples were collected from the children, and viral RNA was extracted. Reverse transcription polymerase chain reaction was used for gene amplification, sequencing, and genotype identification of the VP1 region of capsid protein in norovirus. RESULTS: Among the 1 458 stool samples, 158 (10.8%) were positive for norovirus. There was no significant difference in the positive detection rate of norovirus between different years (P>0.05). Boys had a norovirus detection rate of 12.2% (105/860), which was significantly higher than that in girls (8.9%, 53/598) (P=0.043). The children aged 12 to <18 months had the highest norovirus detection rate (16.9%, 51/301). August, September, and October were the epidemic peak season. A total of 23 norovirus-positive samples were also positive for rotavirus. The norovirus detected were mainly GII type (97.5%, 154/158), and only 4 cases were GI type (2.5%, 4/158). The sequencing of the VP1 region of capsid protein in the positive samples showed that GII.4 (69.6%, 110/158) was the dominant genotype, among which 99 (62.7%, 99/158) were GII.4 Sydney 2012, followed by GII.3 (15.2%, 24/158), GII.2 (10.1%, 16/158), GII.6 (1.9%, 3/158), and GII.17 (0.6%, 1/158). GI.3 (1.3%, 2/158), GI.2 (0.6%, 1/158), and GI.5 (0.6%, 1/158) were rarely detected. CONCLUSIONS: Norovirus GII.4 Sydney 2012 was the major epidemic strain in the children with norovirus gastroenteritis from 2017 to 2019. Although norovirus infection can exist throughout the year, August to October is the peak period. During this period, norovirus surveillance and key population protection are strengthened to help prevent and control norovirus diarrhea.


Assuntos
Gastroenterite , Norovirus , Criança , Fezes , Feminino , Gastroenterite/epidemiologia , Humanos , Masculino , Norovirus/genética , Filogenia , Estudos Retrospectivos
7.
J Gen Virol ; 102(10)2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34698626

RESUMO

Human noroviruses (HuNoVs) are increasingly becoming the main cause of transmissible gastroenteritis worldwide, with hundreds of thousands of deaths recorded annually. Yet, decades after their discovery, there is still no effective treatment or vaccine. Efforts aimed at developing vaccines or treatment will benefit from a greater understanding of norovirus-host interactions, including the host response to infection. In this review, we provide a concise overview of the evidence establishing the significance of type I and type III interferon (IFN) responses in the restriction of noroviruses. We also critically examine our current understanding of the molecular mechanisms of IFN induction in norovirus-infected cells, and outline the diverse strategies deployed by noroviruses to supress and/or avoid host IFN responses. It is our hope that this review will facilitate further discussion and increase interest in this area.


Assuntos
Infecções por Caliciviridae/imunologia , Infecções por Caliciviridae/virologia , Interferons/fisiologia , Norovirus/imunologia , Norovirus/patogenicidade , Animais , Linhagem Celular , Humanos , Evasão da Resposta Imune , Imunidade Inata , Interferons/biossíntese , Proteínas Virais/metabolismo , Replicação Viral
8.
BMC Infect Dis ; 21(1): 1122, 2021 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-34717565

RESUMO

BACKGROUND: Norovirus (NoV) is the main cause of non-bacterial acute gastroenteritis (AGE) outbreaks worldwide. From September 2015 through August 2018, 203 NoV outbreaks involving 2500 cases were reported to the Shenzhen Center for Disease Control and Prevention. METHODS: Faecal specimens for 203 outbreaks were collected and epidemiological data were obtained through the AGE outbreak surveillance system in Shenzhen. Genotypes were determined by sequencing analysis. To gain a better understanding of the evolutionary characteristics of NoV in Shenzhen, molecular evolution and mutations were evaluated based on time-scale evolutionary phylogeny and amino acid mutations. RESULTS: A total of nine districts reported NoV outbreaks and the reported NoV outbreaks peaked from November to March. Among the 203 NoV outbreaks, 150 were sequenced successfully. Most of these outbreaks were associated with the NoV GII.2[P16] strain (45.3%, 92/203) and occurred in school settings (91.6%, 186/203). The evolutionary rates of the RdRp region and the VP1 sequence were 2.1 × 10-3 (95% HPD interval, 1.7 × 10-3-2.5 × 10-3) substitutions/site/year and 2.7 × 10-3 (95% HPD interval, 2.4 × 10-3-3.1 × 10-3) substitutions/site/year, respectively. The common ancestors of the GII.2[P16] strain from Shenzhen and GII.4 Sydney 2012[P16] diverged from 2011 to 2012. The common ancestors of the GII.2[P16] strain from Shenzhen and previous GII.2[P16] (2010-2012) diverged from 2003 to 2004. The results of amino acid mutations showed 6 amino acid substitutions (*77E, R750K, P845Q, H1310Y, K1546Q, T1549A) were found only in GII.4 Sydney 2012[P16] and the GII.2[P16] recombinant strain. CONCLUSIONS: This study illustrates the molecular epidemiological patterns in Shenzhen, China, from September 2015 to August 2018 and provides evidence that the epidemic trend of GII.2[P16] recombinant strain had weakened and the non-structural proteins of the recombinant strain might have played a more significant role than VP1.


Assuntos
Infecções por Caliciviridae , Gastroenterite , Norovirus , Infecções por Caliciviridae/epidemiologia , China/epidemiologia , Surtos de Doenças , Gastroenterite/epidemiologia , Genótipo , Humanos , Norovirus/genética , Filogenia , Estudos Retrospectivos
9.
J Biol Chem ; 297(4): 101225, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34562449

RESUMO

The norovirus genome consists of a single positive-stranded RNA. The mechanism by which this single-stranded RNA genome is replicated is not well understood. To reveal the mechanism underlying the initiation of the norovirus genomic RNA synthesis by its RNA-dependent RNA polymerase (RdRp), we used an in vitro assay to detect the complementary RNA synthesis activity. Results showed that the purified recombinant RdRp was able to synthesize the complementary positive-sense RNA from a 100-nt template corresponding to the 3'-end of the viral antisense genome sequence, but that the RdRp could not synthesize the antisense genomic RNA from the template corresponding to the 5'-end of the positive-sense genome sequence. We also predicted that the 31 nt region at the 3'-end of the RNA antisense template forms a stem-loop structure. Deletion of this sequence resulted in the loss of complementary RNA synthesis by the RdRp, and connection of the 31 nt to the 3'-end of the inactive positive-sense RNA template resulted in the gain of complementary RNA synthesis by the RdRp. Similarly, an electrophoretic mobility shift assay further revealed that the RdRp bound to the antisense RNA specifically, but was dependent on the 31 nt at the 3'-end. Therefore, based on this observation and further deletion and mutation analyses, we concluded that the predicted stem-loop structure in the 31 nt end and the region close to the antisense viral genomic stem sequences are both important for initiating the positive-sense human norovirus genomic RNA synthesis by its RdRp.


Assuntos
Genoma Viral , Proteínas de Neoplasias/química , Norovirus/química , Conformação de Ácido Nucleico , RNA Antissenso/química , RNA Viral/química , RNA Polimerase Dependente de RNA/química , Humanos , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Norovirus/genética , RNA Antissenso/genética , RNA Antissenso/metabolismo , RNA Viral/biossíntese , RNA Viral/genética , RNA Polimerase Dependente de RNA/genética , RNA Polimerase Dependente de RNA/metabolismo
10.
J Med Microbiol ; 70(9)2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34516365

RESUMO

Introduction. The identification of enteropathogens is critical for the clinical management of patients with suspected gastrointestinal infection. The FLOW multiplex PCR system (FMPS) is a semi-automated platform (FLOW System, Roche) for multiplex real-time PCR analysis.Hypothesis/Gap Statement. FMPS has greater sensitivity for the detection of enteric pathogens than standard methods such as culture, biochemical identification, immunochromatography or microscopic examination.Aim.The diagnostic performance of the FMPS was evaluated and compared to that of traditional microbiological procedures.Methodology. A total of 10 659 samples were collected and analysed over a period of 7 years. From 2013 to 2018 (every July to September), samples were processed using standard microbiological culture methods. In 2019, the FMPS was implemented using real-time PCR to detect the following enteropathogens: Shigella spp., Salmonella spp., Campylobacter spp., Giardia intestinalis, Entamoeba histolytica, Blastocystis hominis, Cryptosporidum spp., Dientamoeba fragilis, adenovirus, norovirus and rotavirus. Standard microbiological culture methods (2013-2018) included stool culture, microscopy and immunochromatography.Results. A total of 1078 stool samples were analysed prospectively using the FMPS from July to September (2019): bacterial, parasitic and viral pathogens were identified in 15.3, 9.71 and 5.29 % of cases, respectively. During the same period of 6 years (2013-2018), the proportion of positive identifications using standard microbiological methods from 2013 to 2018 was significantly lower. A major significant recovery improvement was observed for all bacteria species tested: Shigella spp./enteroinvasive Escherichia coli (EIEC) (P <0.05), Salmonella spp. (P <0.05) and Campylobacter spp. (P <0.05). Marked differences were also observed for the parasites G. intestinalis, Cryptosporidium spp. and D. fragilis.Conclusion. These results support the value of multiplex real-time PCR analysis for the detection of enteric pathogens in laboratory diagnosis with outstanding performance in identifying labile micro-organisms. The identification of unsuspected micro-organisms for less specific clinical presentations may also impact on clinical practice and help optimize patient management.


Assuntos
Gastroenterite/diagnóstico , Reação em Cadeia da Polimerase Multiplex , Reação em Cadeia da Polimerase em Tempo Real , Adenoviridae/isolamento & purificação , Blastocystis hominis/isolamento & purificação , Campylobacter/isolamento & purificação , Cryptosporidium/isolamento & purificação , Dientamoeba/isolamento & purificação , Entamoeba histolytica/isolamento & purificação , Fezes/microbiologia , Fezes/parasitologia , Fezes/virologia , Gastroenterite/microbiologia , Gastroenterite/parasitologia , Giardia lamblia/isolamento & purificação , Humanos , Norovirus/isolamento & purificação , Rotavirus/isolamento & purificação , Salmonella/isolamento & purificação , Shigella/isolamento & purificação
11.
Int J Food Microbiol ; 357: 109365, 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34488004

RESUMO

In the agricultural setting, core global food safety elements, such as hand hygiene and worker furlough, should reduce the risk of norovirus contamination on fresh produce. However, the effect of these practices has not been characterized. Using a quantitative microbial risk model, we evaluated the individual and combined effect of farm-based hand hygiene and worker furlough practices on the maximum risk of norovirus infection from three produce commodities (open leaf lettuce, vine tomatoes, and raspberries). Specifically, we tested two scenarios where a harvester's and packer's norovirus infection status was: 1) assumed positive; or 2) assigned based on community norovirus prevalence estimates. In the first scenario with a norovirus-positive harvester and packer, none of the individual interventions modeled reduced produce contamination to below the norovirus infectious dose. However, combined interventions, particularly high handwashing compliance (100%) and efficacy (6 log10 virus removal achieved using soap and water for 30 s), reduced produce contamination to <1-82 residual virus. Translating produce contamination to maximum consumer infection risk, 100% handwashing with a 5 log10 virus removal was necessary to achieve an infection risk below the threshold of 0.032 infections per consumption event. When community-based norovirus prevalence estimates were applied to the harvester and packer, the single interventions of 100% handwashing with 3 log10 virus removal (average 0.02 infection risk per consumption event) or furlough of the packer (average 0.03 infection risk per consumption event) reduced maximum infection risk to below the 0.032 threshold for all commodities. Bundled interventions (worker furlough, 100% glove compliance, and 100% handwashing with 1-log10 virus reduction) resulted in a maximum risk of 0.02 per consumption event across all commodities. These results advance the evidence-base for global produce safety standards as effective norovirus contamination and risk mitigation strategies.


Assuntos
Infecções por Caliciviridae , Norovirus , Rubus , Infecções por Caliciviridae/prevenção & controle , Contaminação de Alimentos/análise , Contaminação de Alimentos/prevenção & controle , Desinfecção das Mãos , Humanos , Alface
12.
Antivir Chem Chemother ; 29: 20402066211025175, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34525875

RESUMO

Human norovirus is the main cause of viral gastroenteritis, resulting annually in ∼ 700 million infections and 200,000 deaths, of whom most are children <5 years. Mouse norovirus-infected macrophages are the most widely used in vitro system to screen and characterize the antiviral effect of norovirus-targeting small molecules. We have previously established antiviral assays using this system, identified novel inhibitors and performed additional studies in order to have a first insight into their mechanism of action. After the identification of novel small molecules with anti-norovirus activity (part 1 of this protocol), we here describe the logical next step which entails the generation of early information of their mode of action. This information together with a continuous improvement of the potency of compounds will contribute to the optimization of a compound class towards in vivo efficacy and a successful preclinical development.


Assuntos
Infecções por Caliciviridae , Norovirus , Animais , Antivirais/farmacologia , Antivirais/uso terapêutico , Infecções por Caliciviridae/tratamento farmacológico , Técnicas de Cultura de Células , Camundongos , Replicação Viral
13.
J Hosp Infect ; 117: 74-80, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34547321

RESUMO

BACKGROUND: Environmental contamination of norovirus (NoV) is believed to be a significant source for further transmission in hospitals. AIM: To investigate the risk of acquiring NoV in a cleaned room previously occupied by a patient with NoV infection. The risk of having a roommate with recent NoV infection was also assessed. METHODS: In a retrospective cohort, comprising 33,788 room stays at five infectious Disease wards in southern Sweden from 2013 to 2018, the risk of acquiring NoV infection after admission to an exposed or non-exposed room was analysed with uni- and multivariable statistical analysis, controlling for age, colonization pressure and any roommate. RNA sequencing of the NoV strains involved in suspected room transmission was also performed. RESULTS: Five of the 1106 patients exposed to a room with a prior occupant with NoV infection and 49 in the non-exposed group acquired NoV infection. An association between NoV acquisition was found in the univariable analysis (odds ratio (OR) 3.3, P=0.01), but not when adjusting for potential confounders (OR 1.9, P=0.2). Sequencing of the NoV samples showed that only two of the five exposed patients with acquired NoV infection were infected by identical strains to the prior room occupant, inferring a room transmission risk of 0.2% (95% confidence interval 0.05-0.78%). None of the 52 patients who shared room with a roommate with NoV symptoms resolved for ≥48 h acquired NoV infection. CONCLUSIONS: In absolute terms, the risk of room transmission of NoV is low. Discontinuation of isolation ≥48 h after resolution of symptoms seems adequate.


Assuntos
Infecções por Caliciviridae , Infecção Hospitalar , Norovirus , Infecções por Caliciviridae/epidemiologia , Estudos de Coortes , Infecção Hospitalar/epidemiologia , Humanos , Norovirus/genética , Estudos Retrospectivos
14.
Int J Pharm ; 609: 121126, 2021 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-34560208

RESUMO

A bivalent Norovirus vaccine candidate has been developed that contains Norovirus strain GI.1 Norwalk-virus like particles (VLP) and strain GII.4 Consensus VLP adsorbed on aluminum (oxy)hydroxide. The Norwalk and Consensus antigens have different stability profiles, making it challenging to prepare a dry powder form of the Norovirus vaccine while maintaining the potency of both antigens. In the present study, we tested the feasibility of converting the vaccine from a liquid suspension to dry powders by thin-film freeze-drying (TFFD). With the proper amount of trehalose and/or sucrose as cryoprotectant (i.e. sucrose alone at 4.55% or 5.55%, w/v, or trehalose at 3-4% with 0.55% of sucrose), TFFD can be applied to successfully convert the Norovirus vaccine candidate into dry powders without causing antigen loss or particle aggregation, while maintaining the relative potency of both antigens within a specified acceptable range. In an accelerated stability study, the potency of the antigens was also maintained in the specified acceptable range after the dry powders prepared by TFFD in the presence of 5.55% (w/v) of sucrose were stored for eight weeks at 40 °C, 75% relative humidity. It is concluded that it is feasible to apply TFFD to convert the Norovirus vaccine from a liquid suspension to stable dry powders.


Assuntos
Norovirus , Vacinas , Liofilização , Pós , Vacinas Combinadas
15.
J Med Internet Res ; 23(9): e24554, 2021 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-34586079

RESUMO

BACKGROUND: Norovirus is a contagious disease. The transmission of norovirus spreads quickly and easily in various ways. Because effective methods to prevent or treat norovirus have not been discovered, it is important to rapidly recognize and report norovirus outbreaks in the early phase. Internet search has been a useful method for people to access information immediately. With the precise record of internet search trends, internet search has been a useful tool to manifest infectious disease outbreaks. OBJECTIVE: In this study, we tried to discover the correlation between internet search terms and norovirus infection. METHODS: The internet search trend data of norovirus were obtained from Google Trends. We used cross-correlation analysis to discover the temporal correlation between norovirus and other terms. We also used multiple linear regression with the stepwise method to recognize the most important predictors of internet search trends and norovirus. In addition, we evaluated the temporal correlation between actual norovirus cases and internet search terms in New York, California, and the United States as a whole. RESULTS: Some Google search terms such as gastroenteritis, watery diarrhea, and stomach bug coincided with norovirus Google Trends. Some Google search terms such as contagious, travel, and party presented earlier than norovirus Google Trends. Some Google search terms such as dehydration, bar, and coronavirus presented several months later than norovirus Google Trends. We found that fever, gastroenteritis, poison, cruise, wedding, and watery diarrhea were important factors correlated with norovirus Google Trends. In actual norovirus cases from New York, California, and the United States as a whole, some Google search terms presented with, earlier, or later than actual norovirus cases. CONCLUSIONS: Our study provides novel strategy-based internet search evidence regarding the epidemiology of norovirus.


Assuntos
Infecções por Coronavirus , Gastroenterite , Norovirus , Infecções por Coronavirus/epidemiologia , Surtos de Doenças , Humanos , Internet , Ferramenta de Busca , Estados Unidos/epidemiologia
16.
J Gen Virol ; 102(9)2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34491891

RESUMO

Murine norovirus (MNV) is widely used as a model for studying norovirus biology. While MNV isolates vary in their pathogenesis, infection of immunocompetent mice mostly results in persistent infection. The ability of a virus to establish a persistent infection is dependent on its ability to subvert or avoid the host immune response. Previously, we described the identification and characterization of virulence factor 1 (VF1) in MNV, and demonstrated its role as an innate immune antagonist. Here, we explore the role of VF1 during persistent MNV infection in an immunocompetent host. Using reverse genetics, we generated MNV-3 viruses carrying a single or a triple termination codon inserted in the VF1 ORF. VF1-deleted MNV-3 replicated to comparable levels to the wildtype virus in tissue culture. Comparative studies between MNV-3 and an acute MNV-1 strain show that MNV-3 VF1 exerts the same functions as MNV-1 VF1, but with reduced potency. C57BL/6 mice infected with VF1-deleted MNV-3 showed significantly reduced replication kinetics during the acute phase of the infection, but viral loads rapidly reached the levels seen in mice infected with wildtype virus after phenotypic restoration of VF1 expression. Infection with an MNV-3 mutant that had three termination codons inserted into VF1, in which reversion was suppressed, resulted in consistently lower replication throughout a 3 month persistent infection in mice, suggesting a role for VF1 in viral fitness in vivo. Our results indicate that VF1 expressed by a persistent strain of MNV also functions to antagonize the innate response to infection. We found that VF1 is not essential for viral persistence, but instead contributes to viral fitness in mice. These data fit with the hypothesis that noroviruses utilize multiple mechanisms to avoid and/or control the host response to infection and that VF1 is just one component of this.


Assuntos
Infecções por Caliciviridae/virologia , Norovirus/patogenicidade , Proteínas Virais/metabolismo , Fatores de Virulência/metabolismo , Animais , Apoptose , Infecções por Caliciviridae/imunologia , Linhagem Celular , Imunidade Inata , Interferon beta/biossíntese , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Norovirus/genética , Norovirus/fisiologia , Proteínas Virais/genética , Virulência , Fatores de Virulência/genética , Replicação Viral , Eliminação de Partículas Virais
17.
Environ Pollut ; 291: 118164, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34534825

RESUMO

The human norovirus (HNoV), on a global scale, is the prevailing cause of contagious viral gastroenteritis outbreaks, with more than 200 000 deaths annually. This study aimed at assessing specific prevalence of HNoV pollution in different water sources and their roles in the dissemination of HNoV, with a view to refocus water sources and sewage management options for policy making towards public health safety. In this regard, we conducted a systematic review and meta-analysis (SR/MA) of the prevalence of HNoV in water sources. We searched PubMed, Google Scholar, Scopus and Web of Science for studies on HNoV prevalence in water sources without temporal restriction, till January 30, 2021. We conducted a random-effects meta-analysis of the HNoV prevalence and stratified the study by water type, continent, gross national income (GNI) group and genogroup. Further, a mixed-effects meta-regression model was performed for sensitivity analysis. The literature search identified 61 studies on water source-based HNoV (WsHNoV) prevalence. The pooled WsHNoV prevalence was 31.7% (95%CI: 25.1-38.5) but varied according to water sources types; river water showing the highest estimate at 43.5% (95%CI: 33.9-53.4), followed by estuarine water (30.6%, 95%CI: 12.5-52.2), composite water (27.9%, 95%CI: 13.5-44.9), marine water (25.9%, 95%CI: 10.0-45.6), groundwater (19.7%, 95%CI: 9.4-32.3) and lake water (2.2%, 95%CI: 0-25.8). Further, the findings indicated the highest WsHNoV prevalence in Africa as 55.9% (95% CI: 28.2-81.9), followed by Asia (31.6%, 95% CI: 22.3-41.6), Europe (29.8%, 95% CI: 17.9-43.2), North America (27.7%, 95% CI: 11.2-47.6) and South America (27.1%, 95%CI: 0.09-49.4). The WsHNoV prevalence stratified by GNI group was 40.6% (95%CI: 27.9-53.9) in middle-income countries and 28.7% (95%CI: 21.7-36.1) in high-income countries respectively. The prevalence of GI, GII and GI & GII genogroup in natural water was 16.4% (95%CI: 12.0-21.3), 20.6% (95%CI: 15.7-25.8) and 12.8% (95%CI: 6.9-20.6) respectively. Evidently, prevalence of the HNoV genogroup in water sources mirrors the pattern of HNoV gastroenteritis and GII genogroup dominance worldwide. In conclusion, public health efforts against waterborne diseases should prioritize water resource/sewage management options and policies towards ardent water sources pollution prevention.


Assuntos
Norovirus , Europa (Continente) , Genótipo , Humanos , Esgotos , Água
18.
Clin Infect Dis ; 73(4): e913-e920, 2021 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-34398953

RESUMO

BACKGROUND: Acute gastroenteritis (AGE) causes a substantial burden in the United States, but its etiology frequently remains undetermined. Active surveillance within an integrated healthcare delivery system was used to estimate the prevalence and incidence of medically attended norovirus, rotavirus, sapovirus, and astrovirus. METHODS: Active surveillance was conducted among all enrolled members of Kaiser Permanente Northwest during July 2014-June 2016. An age-stratified, representative sample of AGE-associated medical encounters were recruited to provide a stool specimen to be tested for norovirus, rotavirus, sapovirus, and astrovirus. Medically attended AGE (MAAGE) encounters for a patient occurring within 30 days were grouped into 1 episode, and all-cause MAAGE incidence was calculated. Pathogen- and healthcare setting-specific incidence estimates were calculated using age-stratified bootstrapping. RESULTS: The overall incidence of MAAGE was 40.6 episodes per 1000 person-years (PY), with most episodes requiring no more than outpatient care. Norovirus was the most frequently detected pathogen, with an incidence of 5.5 medically attended episodes per 1000 PY. Incidence of norovirus MAAGE was highest among children aged < 5 years (20.4 episodes per 1000 PY), followed by adults aged ≥ 65 years (4.5 episodes per 1000 PY). Other study pathogens showed similar patterns by age, but lower overall incidence (sapovirus: 2.4 per 1000 PY; astrovirus: 1.3 per 1000 PY; rotavirus: 0.5 per 1000 PY). CONCLUSIONS: Viral enteropathogens, particularly norovirus, are important contributors to MAAGE, especially among children < 5 years of age. The present findings underline the importance of judicious antibiotics use for pediatric AGE and suggest that an effective norovirus vaccine could substantially reduce MAAGE.


Assuntos
Infecções por Caliciviridae , Gastroenterite , Norovirus , Infecções por Rotavirus , Rotavirus , Sapovirus , Adulto , Infecções por Caliciviridae/epidemiologia , Criança , Fezes , Gastroenterite/epidemiologia , Humanos , Lactente , Estados Unidos/epidemiologia
19.
Viruses ; 13(7)2021 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-34372557

RESUMO

Human coronaviruses, including SARS-CoV-2, are known to spread mainly via close contact and respiratory droplets. However, other potential means of transmission may be present. Fomite-mediated transmission occurs when viruses are deposited onto a surface and then transfer to a subsequent individual. Surfaces can become contaminated directly from respiratory droplets or from a contaminated hand. Due to mask mandates in many countries around the world, the former is less likely. Hands can become contaminated if respiratory droplets are deposited on them (i.e., coughing or sneezing) or through contact with fecal material where human coronaviruses (HCoVs) can be shed. The focus of this paper is on whether human coronaviruses can transfer efficiently from contaminated hands to food or food contact surfaces. The surfaces chosen were: stainless steel, plastic, cucumber and apple. Transfer was first tested with cellular maintenance media and three viruses: two human coronaviruses, 229E and OC43, and murine norovirus-1, as a surrogate for human norovirus. There was no transfer for either of the human coronaviruses to any of the surfaces. Murine norovirus-1 did transfer to stainless steel, cucumber and apple, with transfer efficiencies of 9.19%, 5.95% and 0.329%, respectively. Human coronavirus OC43 transfer was then tested in the presence of fecal material, and transfer was observed for stainless steel (0.52%), cucumber (19.82%) and apple (15.51%) but not plastic. This study indicates that human coronaviruses do not transfer effectively from contaminated hands to contact surfaces without the presence of fecal material.


Assuntos
COVID-19/transmissão , Infecções por Coronavirus/transmissão , Microbiologia de Alimentos , SARS-CoV-2/fisiologia , COVID-19/virologia , Linhagem Celular , Resfriado Comum/transmissão , Coronavirus/isolamento & purificação , Coronavirus Humano 229E/isolamento & purificação , Coronavirus Humano OC43/isolamento & purificação , Contaminação de Equipamentos , Fezes/virologia , Fômites , Doenças Transmitidas por Alimentos/virologia , Humanos , Norovirus/isolamento & purificação , Aço Inoxidável
20.
PLoS One ; 16(8): e0256638, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34432849

RESUMO

BACKGROUND: The COVID-19 pandemic has impacted surveillance activities for multiple pathogens. Since March 2020, there was a decline in the number of reports of norovirus and Campylobacter recorded by England's national laboratory surveillance system. The aim is to estimate and compare the impact of the COVID-19 pandemic on norovirus and Campylobacter surveillance data in England. METHODS: We utilised two quasi-experimental approaches based on a generalised linear model for sequential count data. The first approach estimates overall impact and the second approach focuses on the impact of specific elements of the pandemic response (COVID-19 diagnostic testing and control measures). The following time series (27, 2015-43, 2020) were used: weekly laboratory-confirmed norovirus and Campylobacter reports, air temperature, conducted Sars-CoV-2 tests and Index of COVID-19 control measures stringency. RESULTS: The period of Sars-CoV-2 emergence and subsequent sustained transmission was associated with persistent reductions in norovirus laboratory reports (p = 0.001), whereas the reductions were more pronounced during pandemic emergence and later recovered for Campylobacter (p = 0.075). The total estimated reduction was 47% - 79% for norovirus (12-43, 2020). The total reduction varied by time for Campylobacter, e.g. 19% - 33% in April, 1% - 7% in August. CONCLUSION: Laboratory reporting of norovirus was more adversely impacted than Campylobacter by the COVID-19 pandemic. This may be partially explained by a comparatively stronger effect of behavioural interventions on norovirus transmission and a relatively greater reduction in norovirus testing capacity. Our study underlines the differential impact a pandemic may have on surveillance of gastrointestinal infectious diseases.


Assuntos
COVID-19/epidemiologia , Infecções por Caliciviridae/diagnóstico , Infecções por Campylobacter/diagnóstico , Laboratórios/estatística & dados numéricos , COVID-19/virologia , Teste para COVID-19 , Infecções por Caliciviridae/epidemiologia , Infecções por Caliciviridae/virologia , Campylobacter/isolamento & purificação , Infecções por Campylobacter/epidemiologia , Infecções por Campylobacter/microbiologia , Inglaterra/epidemiologia , Humanos , Norovirus/isolamento & purificação , Pandemias , SARS-CoV-2/isolamento & purificação
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