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1.
PLoS One ; 15(7): e0236502, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32702014

RESUMO

The transmission of human norovirus excreted from infected persons occasionally causes sporadic infections and outbreaks. Both symptomatic patients and asymptomatic carriers have been reported to contribute to norovirus transmission, but little is known about the magnitude of the contribution of asymptomatic carriers. We carried out a 1-year survey of residents of a district of Bangkok, Thailand to determine the percentage of norovirus transmissions originating from asymptomatic individuals. We screened 38 individuals recruited from 16 families from May 2018 to April 2019 for GI and GII genotypes. Norovirus was detected every month, and 101 of 716 stool samples (14.1%) from individuals with no symptoms of acute gastroenteritis were norovirus-positive. The average infection frequency was 2.4 times per person per year. Fourteen genotypes were identified from the positive samples, with GII.4 being detected most frequently. Notably, 89.1% of the norovirus-positive samples were provided by individuals with no diarrhea episode. Similar to cases of symptomatic infections in Thailand, asymptomatic infections were observed most frequently in December. We detected 4 cases of NV infection caused by household transmission, and 3 of the 4 transmissions originated from asymptomatic individuals. We also identified a case in which norovirus derived from an asymptomatic individual caused diarrhea in a family member. These results suggest that asymptomatic individuals play a substantial role in both the maintenance and spreading of norovirus in a community through household transmission.


Assuntos
Infecções Assintomáticas/epidemiologia , Infecções por Caliciviridae/transmissão , Gastroenterite/virologia , Norovirus/patogenicidade , Adolescente , Adulto , Idoso , Infecções por Caliciviridae/patologia , Infecções por Caliciviridae/virologia , Criança , Diarreia/patologia , Diarreia/virologia , Surtos de Doenças , Fezes/virologia , Feminino , Gastroenterite/patologia , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Filogenia , RNA Viral/genética , RNA Viral/isolamento & purificação , Adulto Jovem
2.
Nat Commun ; 11(1): 2968, 2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32528015

RESUMO

Human noroviruses are the leading cause of severe childhood diarrhea worldwide, yet we know little about their pathogenic mechanisms. Murine noroviruses cause diarrhea in interferon-deficient adult mice but these hosts also develop systemic pathology and lethality, reducing confidence in the translatability of findings to human norovirus disease. Herein we report that a murine norovirus causes self-resolving diarrhea in the absence of systemic disease in wild-type neonatal mice, thus mirroring the key features of human norovirus disease and representing a norovirus small animal disease model in wild-type mice. Intriguingly, lymphocytes are critical for controlling acute norovirus replication while simultaneously contributing to disease severity, likely reflecting their dual role as targets of viral infection and key components of the host response.


Assuntos
Infecções por Caliciviridae/patologia , Diarreia/virologia , Norovirus/patogenicidade , Animais , Animais Recém-Nascidos , Modelos Animais de Doenças , Feminino , Linfócitos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C
3.
J Virol ; 94(10)2020 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-32161178

RESUMO

The rabbit hemorrhagic disease virus (RHDV), which belongs to the family Caliciviridae and the genus Lagovirus, causes lethal fulminant hepatitis in rabbits. RHDV decreases the activity of antioxidant enzymes regulated by Nrf2 in the liver. Antioxidants are important for the maintenance of cellular integrity and cytoprotection. However, the mechanism underlying the regulation of the Nrf2-antioxidant response element (ARE) signaling pathway by RHDV remains unclear. Using isobaric tags for relative and absolute quantification (iTRAQ) technology, the current study demonstrated that RHDV inhibits the induction of ARE-regulated genes and increases the expression of the p50 subunit of the NF-κB transcription factor. We showed that RHDV replication causes a remarkable increase in reactive oxygen species (ROS), which is simultaneously accompanied by a significant decrease in Nrf2. It was found that nuclear translocation of Keap1 plays a key role in the nuclear export of Nrf2, leading to the inhibition of Nrf2 transcriptional activity. The p50 protein partners with Keap1 to form the Keap1-p50/p65 complex, which is involved in the nuclear translocation of Keap1. Moreover, upregulation of Nrf2 protein levels in liver cell nuclei by tert-butylhydroquinone (tBHQ) delayed rabbit deaths due to RHDV infection. Considered together, our findings suggest that RHDV inhibits the Nrf2-dependent antioxidant response via nuclear translocation of Keap1-NF-κB complex and nuclear export of Nrf2 and provide new insight into the importance of oxidative stress during RHDV infection.IMPORTANCE Recent studies have reported that rabbit hemorrhagic disease virus (RHDV) infection reduced Nrf2-related antioxidant function. However, the regulatory mechanisms underlying this process remain unclear. The current study showed that the NF-κB p50 subunit partners with Keap1 to form the Keap1-NF-κB complex, which plays a key role in the inhibition of Nrf2 transcriptional activity. More importantly, upregulated Nrf2 activity delayed the death of RHDV-infected rabbits, strongly indicating the importance of oxidative damage during RHDV infection. These findings may provide novel insights into the pathogenesis of RHDV.


Assuntos
Antioxidantes/metabolismo , Infecções por Caliciviridae/metabolismo , Vírus da Doença Hemorrágica de Coelhos/imunologia , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , NF-kappa B/metabolismo , Animais , Elementos de Resposta Antioxidante , Antioxidantes/farmacologia , Infecções por Caliciviridae/imunologia , Infecções por Caliciviridae/patologia , Núcleo Celular/metabolismo , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Regulação da Expressão Gênica , Células HEK293 , Vírus da Doença Hemorrágica de Coelhos/patogenicidade , Humanos , Hidroquinonas , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Fígado/lesões , Fígado/metabolismo , Fígado/patologia , Fator 2 Relacionado a NF-E2/genética , Estresse Oxidativo , Proteômica , Coelhos , Transdução de Sinais/efeitos dos fármacos , Fator de Transcrição RelA , Replicação Viral
4.
J Gen Virol ; 100(11): 1530-1540, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31596195

RESUMO

The role of commensal microbiota in enteric viral infections has been explored extensively, but the interaction between human gut microbiota (HGM) and human norovirus (HuNoV) is poorly understood. In this study, we established an HGM-Transplanted gnotobiotic (Gn) pig model of HuNoV infection and disease, using an infant stool as HGM transplant and a HuNoV GII.4/2006b strain for virus inoculation. Compared to germ-free Gn pigs, HuNoV inoculation in HGMT Gn pigs resulted in increased HuNoV shedding, characterized by significantly higher shedding titres on post inoculation day (PID) 3, 4, 6, 8 and 9, and significantly longer mean duration of virus shedding. In addition, virus titres were significantly higher in duodenum and distal ileum of HGMT Gn pigs on PID10, while comparable and transient HuNoV viremia was detected in both groups. 16S rRNA gene sequencing demonstrated that HuNoV infection dramatically altered intestinal microbiota in HGMT Gn pigs at the phylum (Proteobacteria, Firmicutes and Bacteroidetes) and genus (Enterococcus, Bifidobacterium, Clostridium, Ruminococcus, Anaerococcus, Bacteroides and Lactobacillus) levels. In summary, enhanced GII.4 HuNoV infection was observed in the presence of HGM, and host microbiota was susceptible to disruption upon HuNoV infection.


Assuntos
Infecções por Caliciviridae/patologia , Disbiose , Microbioma Gastrointestinal , Interações Microbianas , Microbiota , Norovirus/crescimento & desenvolvimento , Animais , Sangue/virologia , Infecções por Caliciviridae/complicações , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Modelos Animais de Doenças , Duodeno/virologia , Transplante de Microbiota Fecal , Genótipo , Vida Livre de Germes , Humanos , Íleo/virologia , Norovirus/classificação , Norovirus/genética , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Suínos , Fatores de Tempo , Carga Viral , Eliminação de Partículas Virais
5.
Epidemiol Infect ; 147: e207, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-31364544

RESUMO

To compare the epidemiologic features (e.g. settings and transmission mode) and patient clinical characteristics associated with outbreaks of different norovirus (Nov) strains, we retrospectively analysed data of Nov outbreaks occurring in Guangzhou, China from 2012 to 2018. The results suggested that outbreaks of Nov GII.2, GII.17 and GII.4 Sydney exhibited different outbreak settings, transmission modes and symptoms. GII.2 outbreaks mainly occurred in kindergartens, elementary and high schools and were transmitted mainly through person-to-person contact. By contrast, GII.4 Sydney outbreaks frequently occurred in colleges and were primarily associated with foodborne transmission. Cases from GII.2 and GII.17 outbreaks reported vomiting more frequently than those from outbreaks associated with GII.4 Sydney.


Assuntos
Infecções por Caliciviridae/epidemiologia , Infecções por Caliciviridae/virologia , Surtos de Doenças , Genótipo , Norovirus/classificação , Norovirus/genética , Adolescente , Adulto , Infecções por Caliciviridae/patologia , Infecções por Caliciviridae/transmissão , Criança , Pré-Escolar , China/epidemiologia , Transmissão de Doença Infecciosa , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Norovirus/isolamento & purificação , Estudos Retrospectivos , Adulto Jovem
7.
PLoS Pathog ; 15(7): e1007940, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31329638

RESUMO

Human norovirus (HNoV) is the leading cause of acute gastroenteritis and is spread by fecal shedding that can often persist for weeks to months after the resolution of symptoms. Elimination of persistent viral reservoirs has the potential to prevent outbreaks. Similar to HNoV, murine norovirus (MNV) is spread by persistent shedding in the feces and provides a tractable model to study molecular mechanisms of enteric persistence. Previous studies have identified non-structural protein 1 (NS1) from the persistent MNV strain CR6 as critical for persistent infection in intestinal epithelial cells (IECs), but its mechanism of action remains unclear. We now find that the function of CR6 NS1 is regulated by apoptotic caspase cleavage. Following induction of apoptosis in infected cells, caspases cleave the precursor NS1/2 protein, and this cleavage is prevented by mutation of caspase target motifs. These mutations profoundly compromise CR6 infection of IECs and persistence in the intestine. Conversely, NS1/2 cleavage is not strictly required for acute replication in extra-intestinal tissues or in cultured myeloid cells, suggesting an IEC-centric role. Intriguingly, we find that caspase cleavage of CR6 NS1/2 reciprocally promotes caspase activity, potentiates cell death, and amplifies spread among cultured IEC monolayers. Together, these data indicate that the function of CR6 NS1 is regulated by apoptotic caspases, and suggest that apoptotic cell death enables epithelial spread and persistent shedding.


Assuntos
Mucosa Intestinal/virologia , Norovirus/patogenicidade , Proteínas não Estruturais Virais/metabolismo , Animais , Apoptose , Infecções por Caliciviridae/etiologia , Infecções por Caliciviridae/patologia , Infecções por Caliciviridae/virologia , Caspases/metabolismo , Células Cultivadas , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Células Epiteliais/virologia , Feminino , Gastroenterite/etiologia , Gastroenterite/patologia , Gastroenterite/virologia , Interações entre Hospedeiro e Microrganismos , Humanos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Masculino , Camundongos , Camundongos Knockout , Modelos Biológicos , Células Mieloides/metabolismo , Células Mieloides/patologia , Células Mieloides/virologia , Norovirus/genética , Norovirus/fisiologia , Proteínas não Estruturais Virais/genética , Replicação Viral , Eliminação de Partículas Virais
8.
Immunol Lett ; 215: 40-44, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31154053

RESUMO

Norovirus (NoV) is now recognized as a major cause of gastroenteritis outbreaks, worldwide. Norovirus replication mechanisms are still poorly understood, mainly because a reliable cell culture system is still lacking. The present study aims at understanding some aspects of the immune response against norovirus, and particularly the capacity of virus like particles (VLPs) from an Italian strain, belonging to the GII.4 genotype predominating worldwide, to interact with target cells via Toll Like Receptors (TLRs). The capacity of GII.4 NoV VLPs to interact and cause the activation of TLR2, 4 and 5 was studied in recombinant HEK cells. The results obtained show the ability of GII.4 NoV VLPs to induce activation of TLR2 and 5. The results on TLRs activation confirm that GII.4 NoV VLPs interact with TLR2 and 5, that may represent putative receptors and play a role in NoV infection of intestinal cells.


Assuntos
Norovirus/imunologia , Receptor 2 Toll-Like/imunologia , Receptor 5 Toll-Like/imunologia , Vírion/imunologia , Infecções por Caliciviridae/genética , Infecções por Caliciviridae/imunologia , Infecções por Caliciviridae/patologia , Células HEK293 , Humanos , Norovirus/genética , Receptor 2 Toll-Like/genética , Receptor 5 Toll-Like/genética , Vírion/genética
9.
Cell Host Microbe ; 25(6): 845-857.e5, 2019 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-31130511

RESUMO

Murine norovirus (MNoV) infects a low percentage of enteric tuft cells and can persist in these cells for months following acute infection. Both tuft-cell tropism and resistance to interferon-λ (IFN-λ)-mediated clearance during persistent infection requires the viral nonstructural protein 1/2 (NS1/2). We show that processing of NS1/2 yields NS1, an unconventionally secreted viral protein that is central for IFN-λ resistance. MNoV infection globally suppresses intestinal IFN-λ responses, which is attributable to secreted NS1. MNoV NS1 secretion is triggered by caspase-3 cleavage of NS1/2, and a secreted form of human NoV NS1 is also observed. NS1 secretion is essential for intestinal infection and resistance to IFN-λ in vivo. NS1 vaccination alone protects against MNoV challenge, despite the lack of induction of neutralizing anti-capsid antibodies previously shown to confer protection. Thus, despite infecting a low number of tuft cells, NS1 secretion allows MNoV to globally suppress IFN responses and promote persistence.


Assuntos
Infecções por Caliciviridae/patologia , Infecções por Caliciviridae/virologia , Citocinas/antagonistas & inibidores , Evasão da Resposta Imune , Norovirus/crescimento & desenvolvimento , Norovirus/patogenicidade , Proteínas não Estruturais Virais/metabolismo , Animais , Modelos Animais de Doenças , Gastroenterite/patologia , Gastroenterite/virologia , Humanos , Camundongos , Fatores de Virulência/metabolismo
10.
Biomed Res Int ; 2019: 5201790, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31080820

RESUMO

Rabbit hemorrhagic disease (RHD) is an acute, high fatal contagious disease induced by rabbit hemorrhagic disease virus (RHDV) with acute severe hepatic injury and causes huge economic loss worldwide. In order to develop an effective and reliable drug to treat this disease in clinic, a prescription formulated with baicalin, linarin, icariin, and notoginsenoside R1 (BLIN) according to the theory of syndrome differentiation and treatment in traditional Chinese veterinary medicine was applied to investigate its curative effects against RHD in vivo. The preliminary study results showed that BLIN prescription exerted good curative effect on RHD therapy. To further validate the curative effect and to investigate the possible related curative mechanisms of this drug, the survival rates, the plasma biochemical indexes of hepatic function, the plasma evaluation indexes of oxidative injury, and the RHDV gene expression levels were detected and then the correlation among these indexes was also analyzed. These results showed that BLIN prescription could significantly increase the survival rate, reduce the hepatic injury severity, alleviate the oxidative injury, and decrease the RHDV gene expression level in rabbits infected with RHDV. All these results indicate that BLIN prescription possesses outstanding curative effect against RHD, and the curative mechanism may be related to its antioxidant and anti-RHDV activities. Therefore, this prescription can be expected to be exploited into a new candidate for RHD therapy in clinic.


Assuntos
Infecções por Caliciviridae/tratamento farmacológico , Flavonoides/farmacologia , Flavonoides/uso terapêutico , Vírus da Doença Hemorrágica de Coelhos/efeitos dos fármacos , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Infecções por Caliciviridae/sangue , Infecções por Caliciviridae/patologia , Infecções por Caliciviridae/virologia , Relação Dose-Resposta a Droga , Regulação Viral da Expressão Gênica/efeitos dos fármacos , Ginsenosídeos/farmacologia , Ginsenosídeos/uso terapêutico , Glicosídeos/farmacologia , Glicosídeos/uso terapêutico , Vírus da Doença Hemorrágica de Coelhos/genética , Fígado/efeitos dos fármacos , Fígado/lesões , Fígado/patologia , Coelhos , Taxa de Sobrevida
11.
Viruses ; 11(4)2019 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-30974898

RESUMO

Noroviruses are a major cause of viral gastroenteritis. The burden of the norovirus in lowresourcesettings is not well-established due to limited data. This study reviews the norovirusprevalence, epidemiology, and genotype diversity in lower-middle-income countries (LMIC) andin low-income countries (LIC). PubMed was searched up to 14 January 2019 for norovirus studiesfrom all LIC and LMIC (World Bank Classification). Studies that tested gastroenteritis cases and/orasymptomatic controls for norovirus by reverse transcription-polymerase chain reaction (RT-PCR)were included. Sixty-four studies, the majority on children <5 years of age, were identified, and 14%(95% confidence interval; CI 14-15, 5158/36,288) of the gastroenteritis patients and 8% (95% CI 7-9,423/5310) of healthy controls tested positive for norovirus. In LMIC, norovirus was detected in 15%(95% CI 15-16) of cases and 8% (95% CI 8-10) of healthy controls. In LIC, 11% (95% CI 10-12) ofsymptomatic cases and 9% (95% CI 8-10) of asymptomatic controls were norovirus positive.Norovirus genogroup II predominated overall. GII.4 was the predominant genotype in all settings,followed by GII.3 and GII.6. The most prevalent GI strain was GI.3. Norovirus causes a significantamount of gastroenteritis in low-resource countries, albeit with high levels of asymptomaticinfection in LIC and a high prevalence of coinfections.


Assuntos
Infecções por Caliciviridae/epidemiologia , Países em Desenvolvimento , Gastroenterite/epidemiologia , Norovirus/genética , Infecções por Caliciviridae/diagnóstico , Infecções por Caliciviridae/patologia , Infecções por Caliciviridae/virologia , Coinfecção/diagnóstico , Coinfecção/epidemiologia , Coinfecção/patologia , Coinfecção/virologia , Gastroenterite/diagnóstico , Gastroenterite/patologia , Gastroenterite/virologia , Variação Genética , Genótipo , Humanos , Prevalência , Estações do Ano
12.
PLoS Pathog ; 15(4): e1007709, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31017981

RESUMO

Norovirus infection is the leading cause of food-borne gastroenteritis worldwide, being responsible for over 200,000 deaths annually. Studies with murine norovirus (MNV) showed that protective STAT1 signaling controls viral replication and pathogenesis, but the immune mechanisms that noroviruses exploit to induce pathology are elusive. Here, we show that gastrointestinal MNV infection leads to widespread IL-1ß maturation in MNV-susceptible STAT1-deficient mice. MNV activates the canonical Nlrp3 inflammasome in macrophages, leading to maturation of IL-1ß and to Gasdermin D (GSDMD)-dependent pyroptosis. STAT1-deficient macrophages displayed increased MAVS-mediated expression of pro-IL-1ß, facilitating elevated Nlrp3-dependent release of mature IL-1ß upon MNV infection. Accordingly, MNV-infected Stat1-/- mice showed Nlrp3-dependent maturation of IL-1ß as well as Nlrp3-dependent pyroptosis as assessed by in vivo cleavage of GSDMD to its active N-terminal fragment. While MNV-induced diarrheic responses were not affected, Stat1-/- mice additionally lacking either Nlrp3 or GSDMD displayed lower levels of the fecal inflammatory marker Lipocalin-2 as well as delayed lethality after gastrointestinal MNV infection. Together, these results uncover new insights into the mechanisms of norovirus-induced inflammation and cell death, thereby revealing Nlrp3 inflammasome activation and ensuing GSDMD-driven pyroptosis as contributors to MNV-induced immunopathology in susceptible STAT1-deficient mice.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Infecções por Caliciviridae/patologia , Trato Gastrointestinal/patologia , Inflamassomos/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Piroptose/fisiologia , Fator de Transcrição STAT1/fisiologia , Animais , Proteínas Reguladoras de Apoptose/genética , Infecções por Caliciviridae/imunologia , Infecções por Caliciviridae/metabolismo , Infecções por Caliciviridae/virologia , Células Cultivadas , Trato Gastrointestinal/imunologia , Trato Gastrointestinal/metabolismo , Trato Gastrointestinal/virologia , Inflamassomos/metabolismo , Interleucina-1beta/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/patologia , Macrófagos/virologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Norovirus/imunologia , Norovirus/patogenicidade , Proteínas de Ligação a Fosfato
13.
Vet Clin Pathol ; 48(1): 89-95, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30861586

RESUMO

Two pet rabbits were presented with an acute decrease in appetite and activity. Rabbit 1 showed severe hypothermia, bradycardia, arrhythmias, a heart murmur, dyspnea, occlusion of the nares with secretions, icterus, dehydration, and gaseous gastrointestinal dilation. The urine was dark yellow. Rabbit 2 was overweight, apathetic, and dehydrated; this animal presented with a heart murmur, gastric dilation, and intermittent nystagmus with dorsal strabismus in the right eye. Blood gas, electrolyte, hematology, plasma clinical biochemistry analysis, coagulation profile, plasma protein electrophoresis, urinalysis, and radiographic examinations were performed. The main shared findings were moderate thrombocytopenia, markedly decreased aspartate aminotransferase and alanine aminotransferase activities and fibrinogen concentrations, prolonged prothrombin and activated partial thromboplastin times, profoundly increased alkaline phosphatase and gamma-glutamyl transferase (GGT) activities, and high bile acid and bilirubin concentrations. Rabbit 1 also had respiratory acidosis, marked hypoglycemia, hyperphosphatemia, and a profoundly increased creatine kinase activity. Gastric dilation was observed on both radiographic exams. A low urinary pH of 5-6, marked bilirubinuria and proteinuria, and high urinary GGT levels were present in both patients. Marked icterus developed before death, which occurred within 22 and 30 hours post admission in rabbits 1 and 2, respectively. The necropsy of rabbit 1 showed a markedly accentuated hepatic lobular pattern, pulmonary hemorrhages, pericardial effusion with adhesions, peritoneal petechiae, and icteric and hemorrhagic abdominal fat. Histopathologic findings included hemorrhagic diathesis, severe centroacinar and midzonal hepatocellular necrosis, severe necrosuppurative bronchopneumonia, and moderate cardiomyocyte necrosis. A liver PCR assay was positive for Rabbit Hemorrhagic Disease Virus (RHDV) 2 (RHDV2) and negative for classic RHDV. This is the first description of the gross clinicopathologic abnormalities associated with naturally occurring RHDV2 infection in pet rabbits.


Assuntos
Infecções por Caliciviridae/veterinária , Vírus da Doença Hemorrágica de Coelhos , Coelhos/virologia , Animais , Infecções por Caliciviridae/diagnóstico , Infecções por Caliciviridae/patologia , Infecções por Caliciviridae/virologia , Feminino , Coração/virologia , Fígado/patologia , Fígado/virologia , Pulmão/patologia , Pulmão/virologia , Masculino , Miocárdio/patologia , Útero/patologia , Útero/virologia
14.
J Infect Dev Ctries ; 13(4): 274-277, 2019 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-32045370

RESUMO

INTRODUCTION: Norovirus (NoV) is a contagious virus causing acute gastroenteritis and is mainly responsible for diarrheal outbreak in closed settings. The aims of this study were to describe the epidemiological characteristic of an outbreak in a boarding school, to assess the extent of the outbreak and to implement appropriate control measures. METHODOLOGY: A descriptive study was conducted to describe the epidemiological characteristics of the outbreak. Data on demographic details, onset of abdominal symptoms, food intake history and contact with ill person three days prior to illness were obtained. RESULTS: Twelve fresh stool and 14 food samples were tested for NoV and enteric pathogens, respectively. Out of 745 students, 42 (5.6%) were infected during this outbreak. Predominant clinical features were diarrhea (76.1%), vomiting (71.4%) and abdominal pain (67%). Eight (67%) stool samples and six (43.9%)food samples were positive for NoV and total coliforms, respectively. The dissemination of the disease was due to poor hygiene practices among students. Quarantine was imposed until the last case on September 28, 2016. The outbreak was declared over on September 30, 2016. CONCLUSIONS: A NoV outbreak was determined first time in Malaysia. Environmental assessment showed poor hygienic conditions in the school's kitchen. The number of infected students increased considerably despite the implementation of preventive and control measures. Quarantine was effective to stop the outbreak which is characteristics of NoV outbreak.


Assuntos
Infecções por Caliciviridae/epidemiologia , Surtos de Doenças , Gastroenterite/epidemiologia , Norovirus/isolamento & purificação , Adolescente , Infecções por Caliciviridae/patologia , Demografia , Fezes/virologia , Feminino , Gastroenterite/patologia , Humanos , Controle de Infecções/métodos , Malásia/epidemiologia , Masculino , Instituições Acadêmicas , Estudantes
15.
Zhonghua Liu Xing Bing Xue Za Zhi ; 40(12): 1560-1562, 2019 Dec 10.
Artigo em Chinês | MEDLINE | ID: mdl-32062915

RESUMO

Objective: To explore the duration of intestinal detoxification and its related factors infected with Norovirus, and to provide scientific evidences for the prevention and control of acute gastroenteritis caused by Norovirus in the future. Methods: Follow up and sampling program on 115 employees in a restaurant outbreak of Norovirus in Chengdu in 2017 was carried out. Anal swab was collected every 3 d or 7 d for nucleic acid detection, and the experimental results were statistically analyzed. Results: The positive rates of Norovirus in restaurant employee were 14.78%, 7.89%, 3.51% and 0.88% on the 7(th), 11(th), 17(th) and 24(th) day, respectively. During the follow-up period, the positive rates of Norovirus decreased as time increased. The positive rate of all employees was up to 14.78% on the 7(th) day. The positive rates had no significant difference between different sex and between different types of work. The duration of detoxification averaged 14.94 days and the maximum of detoxification time was on 28 days. The detoxification period of treatment case was shorter than that of asymptomatic carriers. Conclusions: There were asymptomatic carriers in restaurant employees during the outbreak of Norovirus that their role as a source of infection in the transmission of Norovirus should not be neglected. In the treatment of the epidemic, we should strengthen the sampling and testing of practitioners, and strictly implement isolation measures for positive detection.


Assuntos
Infecções por Caliciviridae , Gastroenterite , Norovirus , Infecções Assintomáticas , Infecções por Caliciviridae/patologia , Surtos de Doenças , Gastroenterite/patologia , Humanos , Restaurantes , Eliminação de Partículas Virais
16.
Methods Mol Biol ; 1576: 229-247, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-28361480

RESUMO

Human rotavirus (HRV) and human norovirus (HuNoV) infections are recognized as the most common causes of epidemic and sporadic cases of gastroenteritis worldwide. The study of these two human gastrointestinal viruses is important for understanding basic virus-host interactions and mechanisms of pathogenesis and to establish models to evaluate vaccines and treatments. Despite the introduction of live-attenuated vaccines to prevent life-threatening HRV-induced disease, the burden of HRV illness remains significant in low-income and less-industrialized countries, and small animal models or ex vivo models to study HRV infections efficiently are lacking. Similarly, HuNoVs remained non-cultivatable until recently. With the advent of non-transformed human intestinal enteroid (HIE) cultures, we are now able to culture and study both clinically relevant HRV and HuNoV in a biologically relevant human system. Methods described here will allow investigators to use these new culture techniques to grow HRV and HuNoV and analyze new aspects of virus replication and pathogenesis.


Assuntos
Infecções por Caliciviridae/virologia , Técnicas de Cultura de Células/métodos , Gastroenteropatias/virologia , Intestinos/virologia , Organoides/virologia , Infecções por Rotavirus/virologia , Replicação Viral , Infecções por Caliciviridae/patologia , Células Cultivadas , Gastroenteropatias/patologia , Trato Gastrointestinal/virologia , Humanos , Intestinos/patologia , Norovirus/isolamento & purificação , Organoides/patologia , Rotavirus/isolamento & purificação , Infecções por Rotavirus/patologia
17.
Diagn Microbiol Infect Dis ; 93(1): 69-73, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30174143

RESUMO

OBJECTIVE: Predictive factors associated with clinical outcomes of chronic norovirus infection (CNI) in primary immunodeficiency diseases (PIDD) are lacking. METHOD: We sought to characterize CNI using a multi-institutional cohort of patients with PIDD and CNI using the Clinical Immunology Society's CIS-PIDD Listserv e-mail group. RESULTS: Thirty-four subjects (21 males and 13 females) were reported from centers across North America, Europe, and Asia. All subjects were receiving high doses (median IgG dose: 1200 mg/kg/month) of supplemental immunoglobulin therapy. Fifty-three percent had a complete absence of B cells (median B-cell count 0; range 0-139 cells/µL). Common Variable Immune Deficiency (CVID) subjects manifested a unique phenotype with B-cell lymphopenia, non O+ blood type, and villous atrophy (logistic regression model, P = 0.01). Five subjects died, all of whom had no evidence of villous atrophy. CONCLUSION: While Norovirus (NoV) is thought to replicate in B cells, in this PIDD cohort of CNI, B-cell lymphopenia was common, indicating that the presence of B lymphocytes is not essential for CNI.


Assuntos
Infecções por Caliciviridae/imunologia , Síndromes de Imunodeficiência/virologia , Norovirus/fisiologia , Adolescente , Adulto , Linfócitos B/patologia , Infecções por Caliciviridae/mortalidade , Infecções por Caliciviridae/patologia , Doença Crônica , Imunodeficiência de Variável Comum/imunologia , Imunodeficiência de Variável Comum/patologia , Imunodeficiência de Variável Comum/terapia , Imunodeficiência de Variável Comum/virologia , Feminino , Gastroenterite/imunologia , Gastroenterite/mortalidade , Gastroenterite/patologia , Humanos , Imunização Passiva , Síndromes de Imunodeficiência/imunologia , Síndromes de Imunodeficiência/patologia , Síndromes de Imunodeficiência/terapia , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Norovirus/genética , Estudos Retrospectivos , Adulto Jovem
18.
BMC Vet Res ; 14(1): 367, 2018 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-30477499

RESUMO

BACKGROUND: Prior to 2010, the lagoviruses that cause rabbit hemorrhagic disease (RHD) in European rabbits (Oryctolagus cuniculus) and European brown hare syndrome (EBHS) in hares (Lepus spp.) were generally genus-specific. However, in 2010, rabbit hemorrhagic disease virus 2 (RHDV2), also known as Lagovirus europaeus GI.2, emerged and had the distinguishing ability to cause disease in both rabbits and certain hare species. The mountain hare (Lepus timidus) is native to Sweden and is susceptible to European brown hare syndrome virus (EBHSV), also called Lagovirus europaeus GII.1. While most mountain hare populations are found on the mainland, isolated populations also exist on islands. Here we investigate a mortality event in mountain hares on the small island of Hallands Väderö where other leporid species, including rabbits, are absent. RESULTS: Post-mortem and microscopic examination of three mountain hare carcasses collected from early November 2016 to mid-March 2017 revealed acute hepatic necrosis consistent with pathogenic lagovirus infection. Using immunohistochemistry, lagoviral capsid antigen was visualized within lesions, both in hepatocytes and macrophages. Genotyping and immunotyping of the virus independently confirmed infection with L. europaeus GI.2, not GII.1. Phylogenetic analyses of the vp60 gene grouped mountain hare strains together with a rabbit strain from an outbreak of GI.2 in July 2016, collected approximately 50 km away on the mainland. CONCLUSIONS: This is the first documented infection of GI.2 in mountain hares and further expands the host range of GI.2. Lesions and tissue distribution mimic those of GII.1 in mountain hares. The virus was most likely initially introduced from a concurrent, large-scale GI.2 outbreak in rabbits on the adjacent mainland, providing another example of how readily this virus can spread. The mortality event in mountain hares lasted for at least 4.5 months in the absence of rabbits, which would have required virus circulation among mountain hares, environmental persistence and/or multiple introductions. This marks the fourth Lepus species that can succumb to GI.2 infection, suggesting that susceptibility to GI.2 may be common in Lepus species. Measures to minimize the spread of GI.2 to vulnerable Lepus populations therefore are prudent.


Assuntos
Infecções por Caliciviridae/veterinária , Lebres , Lagovirus , Animais , Animais Selvagens , Infecções por Caliciviridae/mortalidade , Infecções por Caliciviridae/patologia , Surtos de Doenças/veterinária , Feminino , Lagovirus/classificação , Lagovirus/isolamento & purificação , Masculino , Tipagem Molecular , Filogenia , Sorotipagem/veterinária , Suécia
19.
Adv Food Nutr Res ; 86: 13-53, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30077220

RESUMO

Human noroviruses (HNoVs) are primarily transmitted by the fecal-oral route, either by person-to-person contact, or by ingestion of contaminated food or water as well as by aerosolization. Moreover, HNoVs significantly contribute to foodborne diseases being the causative agent of one-fifth of acute gastroenteritis worldwide. As a consequence of globalization, transnational outbreaks of foodborne infections are reported with increasing frequency. Therefore, in this review, state-of-the-art information regarding molecular procedures for human norovirus detection in food as well common food processing technologies have been summarized. Besides, the purpose of this chapter is to consolidate basic information on various aspects of HNoVs and to summarize food processing technologies that can potentially be applied in the food industry.


Assuntos
Infecções por Caliciviridae/virologia , Norovirus/classificação , Infecções por Caliciviridae/patologia , Infecções por Caliciviridae/transmissão , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/virologia , Humanos , Norovirus/genética , Saúde Pública
20.
Epidemiol Infect ; 146(15): 1955-1964, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30132423

RESUMO

The following paper investigates the prevalence and characteristics of asymptomatic norovirus infection in the population living around oyster farm sites. Two consecutive surveys were conducted from January 2014 to December 2014 and 4549 stool samples were screened during the same time period. The total asymptomatic infection rate was 4.04% (184/4549). Norovirus infection rate was 5.20% in oyster farming population which was significantly higher compared with non-farming population where the infection rate was 3.65% (χ2 = 5.49, P < 0.05). A total of 184 NoV positive samples were identified by real time-quantitative polymerase chain reaction (RT-qPCR) and semi-nested RT-PCR and 136 sequences were obtained. The sequences were clustered into 14 genotypes. GI strains were clustered into six genotypes, including GI.2, GI.3, GI.5, GI.6, GI.8 and GI.9; while GII strains were clustered into GII.2, GII.3, GII.4, GII.5, GII.6, GII.8 and GII.13. GI.9 and GII.17 were the predominant and most prevalent genotypes, respectively. The GII.17 genotype replaced GII.4 becoming the dominant genotype in the oyster farming area in 2014. To sum up, long-term monitoring of asymptomatic infection is crucial for the detection of new variant strains and for identifying outbreaks during the early stage.


Assuntos
Infecções por Caliciviridae/epidemiologia , Fezes/virologia , Norovirus/isolamento & purificação , Ostreidae/crescimento & desenvolvimento , Animais , Aquicultura , Infecções por Caliciviridae/patologia , Infecções por Caliciviridae/virologia , China , Genótipo , Humanos , Norovirus/classificação , Norovirus/genética , Prevalência , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA
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