Virological, Serological, and Clinical Features of an Outbreak of Acute Gastroenteritis Due to Recombinant Genogroup II Norovirus in an Infant Home

Abstract

Norovirus (NV) is an important cause of acute nonbacterial gastroenteritis worldwide. Recently, several sporadic cases due to naturally occurring recombinant NVs have been reported. In January 2000, there was an outbreak of gastroenteritis in an infant home in Sapporo, Japan. Of 34 residents of the home that were less than 2 years old, 23 developed gastrointestinal symptoms and NV infection was confirmed by conventional reverse transcription-PCR to detect the RNA polymerase region of genogroup II NV. In this virus, the RNA polymerase region shared 86% nucleotide identity with Hawaii virus but only 77% with Mexico virus; however, its capsid region shared only 70% identity with Hawaii virus but 90% with Mexico virus. On the other hand, both regions shared a higher 96% nucleotide identity with Arg320 virus, which was found in Mendoza, Argentina, in 1995 and considered to be a recombinant of Hawaii and Mexico viruses. The findings indicate that the virus involved in the outbreak was similar and may have evolved from the Arg320 virus. Clinically the cases were more severe than those of previously reported sporadic or outbreak cases of NV infection.

Surveillance of norovirus infections in the state of Rio De Janeiro, Brazil 2005–2008

“…These data suggest that the latter region is less sensitive for PCR detection due to the occurrence of a mismatch between the primers and the analyzed strains, or to the formation of a secondary structure in the RNA molecule that affects the amplification efficiency, as previously suggested by Mattison et al [2009]. Alternatively, the absence of amplified product when using region D primers might be due to possible recombinant events occurring within the viral genome Tsugawa et al, 2006;Zheng et al, 2006].…”

Molecular and epidemiological features of GIIb norovirus outbreaks in Victoria, Australia, 2002–2005

“…For example, GIIb/GII.3 was the most common recombinant form found in a study of Hungarian norovirus outbreaks in the period January 2001 to May 2004 [Reuter et al, 2006]. Tsugawa et al [2006], in a study of a single norovirus outbreak in January 2000 in Japan, identified GIIb/GII.3 as the recombinant type associated with this outbreak. Fukuda et al [2008], who examined GIIb norovirus outbreaks in Japan over the period December 2001 to April 2006, identified only GIIb/GII.3 recombinants.…”

“…Norovirus classification based on ORF 1 or ORF 2 can give similar clusters [Vinje et al, 2000] but this is not always the case as recombination can result in different genotypic classification in different parts of the genome [Bull et al, 2007]. Recombination in the noroviruses has been reported to occur in the region of the junction of ORF 1 and ORF 2 [Tsugawa et al, 2006;Bull et al, 2007], within ORF 1 itself [Bull et al, 2007;Waters et al, 2007] and within ORF 2 [Rohayem et al, 2005]. Recombination involving different genotypes within the same genogroup is well documented [Bull et al, 2007] but now has also been found to involve different genogroups [Nayak et al, 2008].…”

Epidemiological Characteristics of Norovirus Associated with Sporadic Gastroenteritis among Children from the 2006/2007 to 2011/2012 Season in Nara Prefecture, Japan

“…The genome of NoV encodes three open reading frames (ORFs): ORF1, ORF2, and ORF3 [2,3]. ORF1 encodes nonstructural proteins, ORF2 encodes the major capsid protein, and ORF3 encodes a minor structural protein [2,3]. The majority of human NoVs are classified into two genogroups, GI and GII, which are further subdivided into more than 30 genotypes on the basis of their capsid and/or polymerase genes [4].…”

“…Studies investigating neutralizing antibodies against NoV have not been possible because of the absence of regular tissue culture systems, however recent advances in NoV sequencing have enabled their genomic characterization. The genome of NoV encodes three open reading frames (ORFs): ORF1, ORF2, and ORF3 [2,3]. ORF1 encodes nonstructural proteins, ORF2 encodes the major capsid protein, and ORF3 encodes a minor structural protein [2,3].…”