To the editor: We thank the authors of the letter to the editor for their interest in our report of the detection of a potential new epidemic strain of norovirus [1]. The authors express some doubt as to the validity of our claims of a possible new norovirus GII.4 variant, since the recombinant form (GII.4_NewOrleans_2009/GII.4_ Sydney_2012) has been reported previously in a number of instances...

Noroviruses are endemic in the human population, and are recognised as a leading cause of acute gastroenteritis worldwide. Although they are a highly diverse group of viruses, genogroup-II genotype-4 (GII-4) noroviruses are the most frequently identified strains worldwide. The predominance of GII-4 norovirus strains is driven by the periodic emergence of antigenic variants capable of evading he...

Human norovirus is a major cause of viral acute gastroenteritis worldwide. However, the transition of endemic norovirus genotypes remains poorly understood. The characteristics of natural immunity against norovirus are unclear because few studies have been performed in the natural infection setting. This prospective 10-year surveillance study of acute gastroenteritis in the province of Osaka, J...

Gastroenteritis is one of the most common diseases during childhood, with norovirus (NoV) and sapovirus (SaV) being two of its main causes. This study reports for the first time the incidence of these viruses in hospitalized children with and without gastroenteritis in São Luís, Maranhão. A total of 136 fecal samples were tested by enzyme immunoassays (EIA) for the detection of NoV and by rever...

Norovirus (NV) has caused large outbreaks of gastroenteritis in schools. Studies of NV epidemiology in schools related to NV outbreaks have been frequently reported. However, reports of that in schools without outbreaks are not found. Presently, NV molecular epidemiology surveillance was carried out in asymptomatic food handlers working at nonoutbreak elementary schools in Incheon, Korea, in Ma...

Noroviruses are the leading cause of epidemic gastroenteritis, including foodborne outbreaks, in the United States. Hospitalization and mortality associated with norovirus infection occur most frequently among elderly persons, young children, and immunocompromised patients. Noroviruses belong to the family Caliciviridae and can be grouped into five genogroups (GI through GV), which are further ...

This study aimed to inspect norovirus contamination of groundwater treatment systems used in food-catering facilities located in South Korea. A nationwide study was performed in 2010. Water samples were collected and, for the analysis of water quality, the temperature, pH, turbidity, and residual chlorine content were assessed. To detect norovirus genotypes GI and GII, RT-PCR and semi-nested PC...

BACKGROUND Limited information is available on the molecular epidemiology of GII.4 Sydney-associated diarrhea in China in the winter of 2012-13 during the global epidemic associated with the emergence of GII.4 Sydney. METHODS Fecal specimens collected from 171 diarrhea outpatients (one from each) between late October 2012 and the middle of March 2013 were examined for NoV by reverse transcrip...

CaliciNet, the outbreak surveillance network for noroviruses in the United States, was launched in March 2009. As of January 2011, twenty state and local health laboratories had been certified to submit norovirus sequences and epidemiologic outbreak data to CaliciNet. During the network's first year, 552 outbreaks were submitted to CaliciNet, of which 78 (14%) were associated with foodborne tra...

Norovirus (NoV) is a major cause of gastroenteritis. NoV genotype II.4 (GII.4) is the predominant genotype in health care settings but the reason for this finding is unknown. Stool samples containing isolates with a known NoV genotype from 2,109 patients in Denmark (patients consulting a general practitioner or outpatient clinic, inpatients, and patients from foodborne outbreaks) were used to d...