Emergence of a New Norovirus Genotype II.4 Variant Associated with Global Outbreaks of Gastroenteritis

Bull, Rowena A.; Tu, Elise; McIver, Christopher J.; Rawlinson, William D.; White, Peter A.

doi:10.1128/jcm.44.2.327-333.2006

Cited by 315 publications

(329 citation statements)

References 47 publications

(78 reference statements)

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“…Similarly, the incidence of general practitioner consultations for norovirus was only slightly lower than that from a recent study in Germany, which used RT-PCR diagnosis for norovirus, but again this study had a narrower case definition for IID (2 or more loose stools, or 2 or more vomiting episodes in 24 hours) (21). The incidence of norovirus-associated IID may also have been higher than normal during our study because a new variant of norovirus emerged during 1995 and 1996 (22)(23)(24); emergence of norovirus variants has been associated with increased disease incidence (25)(26)(27)(28).…”

Section: Discussioncontrasting

confidence: 66%

Prevalence and characteristics of asymptomatic norovirus infection in the community in England

et al. 2010

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Existing estimates of the incidence of infectious intestinal disease (IID) caused by norovirus are based on electron microscopy or reverse transcription-polymerase chain reaction (RT-PCR). Neither method accurately represents norovirus disease burden: Electron microscopy has poor diagnostic sensitivity, and RT-PCR has poor diagnostic specificity. In this study, viral load measurements were used to identify cases of norovirus-associated IID and to produce new incidence estimates for England. IID cases were ascertained in the Study of Infectious Intestinal Disease in England (1993England ( -1996, and stool specimens were tested by semiquantitative real-time RT-PCR for norovirus. The age-adjusted community incidence of norovirus-associated IID was 4.5/100 person-years (95% credibility interval: 3.8, 5.2), equating to 2 million episodes/year. Among children aged less than 5 years, the community incidence was 21.4/100 person-years (95% credibility interval: 15.9, 27.7), and the incidence of consultations to general practitioners for norovirus-associated IID was 3.2/100 person-years (95% credibility interval: 2.6, 3.8), with 100,000 children visiting their general practitioner for norovirus-associated IID each year. Norovirus is the most common cause of IID in the community in England and is responsible for a similar number of pediatric primary care consultations as rotavirus.England; gastroenteritis; incidence; Monte Carlo method; Norovirus; primary health care; reverse transcriptase polymerase chain reaction Abbreviations: IID, infectious intestinal disease; ROC, receiver operating characteristic; RT-PCR, reverse transcription-polymerase chain reaction.

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Section: Discussioncontrasting

confidence: 66%

Prevalence and characteristics of asymptomatic norovirus infection in the community in England

et al. 2010

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“…Recently, excretion of norovirus by symptomatic and asymptomatic individuals during a hospital outbreak of gastroenteritis where a GII/4 strain was dominant has been described (6). At present, norovirus GII/4 strains are the most prevalent in many countries (4,8,27,28). What is more, variant GII/4 sequences, i.e., those differing by approximately 5% of amino acids, were speculated to be more virulent and part of the reason for the increased number of infections worldwide (8).…”

Section: Discussionmentioning

confidence: 99%

Norovirus Infections in Symptomatic and Asymptomatic Food Handlers in Japan

Ozawa¹,

et al. 2007

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Noroviruses are the leading cause of outbreaks of gastroenteritis in the world. At present, norovirus genogroup II, genotype 4 (GII/4), strains are the most prevalent in many countries. In this study we investigated 55 outbreaks and 35 sporadic cases of norovirus-associated gastroenteritis in food handlers in foodcatering settings between 10 November 2005 and 9 December 2006 in Japan. Stool specimens were collected from both symptomatic and asymptomatic individuals and were examined for norovirus by real-time reverse transcription-PCR; the results were then confirmed by sequence analysis. Norovirus was detected in 449 of 2,376 (19%) specimens. Four genogroup I (GI) genotypes and 12 GII genotypes, including one new GII genotype, were detected. The GII/4 sequences were predominant, accounting for 19 of 55 (35%) outbreaks and 16 of 35 (46%) sporadic cases. Our results also showed that a large number of asymptomatic food handlers were infected with norovirus GII/4 strains. Norovirus GII had a slightly higher mean viral load (1 log unit higher) than norovirus GI, i.e., 3.81 ؋ 10 8 versus 2.79 ؋ 10 7 copies/g of stool. Among norovirus GI strains, GI/4 had the highest mean viral load, whereas among GII strains, GII/4 had the highest mean viral load (2.02 ؋ 10 8 and 7.96 ؋ 10 9 copies/g of stool, respectively). Importantly, we found that asymptomatic individuals had mean viral loads similar to those of symptomatic individuals, which may account for the increased number of infections and the predominance of an asymptomatic transmission route.The positive-sense polyadenylated single-stranded RNA virus family Caliciviridae contains four genera: Norovirus, Sapovirus, Lagovirus, and Vesivirus (1). The prototype strain of human norovirus is the Norwalk virus (NV/Human/US/1968), which was first discovered in an outbreak of gastroenteritis in an elementary school in Norwalk, OH, in 1968 (15). Noroviruses are the leading cause of outbreaks of gastroenteritis in the world; they cause outbreaks in various settings, including hospitals, cruise ships, schools, and restaurants (2,9,12,15,23,24,29). In addition, noroviruses have been detected in environmental samples (e.g., treated and untreated sewage) as well as in contaminated foods such as oysters, shellfish, sandwiches, salads, raspberries, and even ice (7,18,19,26). Numerous molecular epidemiological studies have revealed a global distribution of these viruses (25,27,31).The most widely used method of detecting noroviruses is reverse transcription-PCR (RT-PCR), which has high sensitivity; also, the products can be used for further genetic analysis. Real-time RT-PCR assays have also been developed; they are sensitive, broadly reactive, and rapid for the detection of human noroviruses in clinical stool specimens and environmental samples (13,14,21).As the detection methods become more and more sensitive, the numbers of genogroups and genotypes are expected to increase. One emerging characteristic is that strains have been found to persist in one geographical region, only to disapp...

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“…The outbreak strain was assigned, by sequence homology analysis, to the GII.4 variant 2010, considered the pandemic variant responsible of the epidemic events that occurred worldwide during 2009-2010 [Mathijs et al, 2011;Vega et al, 2011]. Over the last decade five NoV pandemic events have been reported associated with the genotype GII.4 and each of them have been trigged from a mutated strain [Blanton et al, 2006;Bull et al, 2006;Tu et al, 2008;Siebenga et al, 2009]. In the absence of a reliable cell culture system, the RT-PCR is considered the gold standard for NoV detection.…”

Section: Characterization Of the Outbreak In Ballshmentioning

confidence: 99%

“…In the last decade the number of reports about NoV outbreaks increased worldwide. Data published by the systems of NoV surveillance (NoroNet; CaliciNet; ViroNet) describe the GII.4 strain as the genotype predominant in human circulating in the world and new GII.4 genetic variants were identified associated with epidemic events [Bull et al, 2006;Tu et al, 2008;Siebenga et al, 2009;Eden et al, 2010]. The literature does not report data about NoV outbreaks in Albania.…”

Section: Introductionmentioning

confidence: 99%

Molecular characterization of norovirus GII strains identified in Albania

Donia

Cenko²,

Divizia

2013

Journal of Medical Virology

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Noroviruses (NoVs) are considered as the leading cause of diarrheal diseases in all groups of age. In the last decade the number of NoV outbreaks worldwide is increasing. Data published by the systems of NoV surveillance show the GII.4 strain as the human predominant genotype circulating worldwide and new genetic variants of GII.4 were associated with epidemic events. In Albania the economy transformation has damaged significantly the environment and a large circulation of enteric viruses was reported in the past with the presence of NoV among the genotyped strains. This study aimed to characterize, by molecular analysis, the NoV GII strains detected in Albania during two time periods: in 2010 from the outbreak occurred in Ballsh and in 2002–2003 from sporadic cases of diarrhoea. A total of 21 Nov GII strains were characterized. The NoV GII.4 was genotyped more frequently and it was related closely to the pandemic variants recorded in GenBank. During 2002–2003, six NoV GII recombinant strains have been characterized

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Emergence of a New Norovirus Genotype II.4 Variant Associated with Global Outbreaks of Gastroenteritis

Cited by 315 publications

References 47 publications

Prevalence and characteristics of asymptomatic norovirus infection in the community in England

Prevalence and characteristics of asymptomatic norovirus infection in the community in England

Norovirus Infections in Symptomatic and Asymptomatic Food Handlers in Japan

Molecular characterization of norovirus GII strains identified in Albania

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