Evidence of the etiological predominance of norovirus in gastroenteritis outbreaks—emerging new‐variant and recombinant noroviruses in Hungary

Abstract

Between January 2001 and December 2003, stool specimens from 262 (45%) of 581 reported outbreaks of gastroenteritis were investigated for noroviruses in Hungary. Specimens collected from outbreaks of non-bacterial gastroenteritis were examined by reverse-transcription polymerase chain reaction and enzyme immunoassay. In 253 (97%) of 262 outbreaks, norovirus was detected and confirmed by sequencing in 211 (81%). Hospitals (35%), day care centers (30%), and elderly homes (27%) were the most common settings. Diversity and frequency of the genotypes changed over time but with predominance (95%) of genogroup (GG) II strains. Strains grouped into 11 genotypes including an epidemic spread of new-variant GGII4 (Lordsdale virus) and a recently emerged group of natural recombinant strains (GGIIb/Hilversum polymerase) with four capsid types (Hawaii, Mexico, Snow Mountain, and Lordsdale). Clusters of epidemics including food-borne outbreaks were detected. According to this study, noroviruses are the predominant etiological agents causing gastroenteritis outbreaks in Hungary.

Emergence of New Norovirus Variants on Spring Cruise Ships and Prediction of Winter Epidemics

“…The differences between the off-seasonal number of reported outbreaks in 2006 (x 1 ) and the off-seasonal numbers of reported outbreaks in previous years (x [2][3][4][5] ) were compared; the difference was signifi cant according to the following equation:…”

“…The symptoms of vomiting and diarrhea occur after a short incubation period of 8 to 72 hours. Although norovirus can cause sporadic cases (1), this contagious virus is often described as a cause of outbreaks (2)(3)(4)(5). In Europe, norovirus outbreaks are reported to the Food Borne Viruses in Europe (FBVE) network.…”

Genetic heterogeneity of porcine enteric caliciviruses identified from diarrhoeic piglets

“…Porcine enteric caliciviruses (PECs), distantly related to the porcine SaV prototype Cowden, have been also described, that are likely members of novel SaV genogroups, GGVI (prototype strain JJ681/ 00/US) and GGVII (prototype strains K7/JP and K10/JP) [20,29]. Genetic recombination has been described frequently between genetically related caliciviruses, within the same genogroup or genotype [30,31] but it may also have occurred between genetically unrelated strains [32]. As the molecular epidemiology of animal caliciviruses is largely unexplored, the understanding of the global ecology of NoVs and SaVs is limited and the role of animals as reservoirs of infections is unclear.…”

Emerging GII.4 norovirus variants affect children with diarrhea in Palermo, Italy in 2006

“…In recent years, recombinant NoV strains, such as GIIb/Hilversum, have been found to be common agents of gastroenteritis in Europe, mainly in children. GIIb/Hilversum NoV strains share a common polymerase gene and display a variety of capsid genes [Ambert-Balay et al, 2005;Reuter et al, 2005]. Restriction fragment length polymorphism (RFLP) analysis applied to RT-PCR amplicons (PCR-RFLP) of the RdRp gene (region A) proved useful to recognize GII.4 and GII.b/Hilversum NoVs as the main cause of sporadic cases of acute gastroenteritis in children admitted to hospital in Italy in 2004 [Colomba et al, 2007].…”