Diversity of Noroviruses throughout Outbreaks in Germany 2018

Abstract

Human norovirus accounts for the majority of viral gastroenteritis cases worldwide. It is a fast evolving virus generating diversity via mutation and recombination. Therefore, new variants and new recombinant strains emerge in the norovirus population. We characterized norovirus positive stool samples from one intensively studied district Märkisch-Oderland state Brandenburg with the samples from other states of Germany in order to understand the molecular epidemiological dynamics of norovirus outbreaks in Germany 2018. PCR systems, Sanger sequencing, and phylogenetic analyses were used for genotyping. Noroviruses of 250 outbreaks in Germany were genotyped, including 39 outbreaks for the district Märkisch-Oderland. Viral diversity in Märkisch-Oderland as compared to Germany was similar, but not identical. The predominant genogroup in Germany was GII with predominate genotype GII.P16-GII.4 Sydney, whereas GII.P31-GII.4 Sydney was the most frequent in Märkisch-Oderland. Genogroup I viruses were less frequently detected, regional and national. Within the sequences of GII.4 recombinants, two distinct clusters were identified with outbreaks from Märkisch-Oderland. Further analysis of sequence data and detailed epidemiological data are needed in order to understand the link between outbreaks in such clusters. Molecular surveillance should be based on samples collected nationally in order to trace comprehensive virus distribution and recombination events in virus population.

Genetic Diversity of Enteric Viruses in Children under Five Years Old in Gabon

“…The most prevalent NoV genotype was GII.P31-GII.4 Sydney, with a 45.2% detection rate. This finding is consistent with the results reported in Germany, Brazil, and China [ 26 , 44 , 45 ]. Surprisingly, we did not find that the emerging recombinant strain GII.P16-GII.4 replaced GII.P31-GII.4 Sydney around the world [ 46 , 47 ].…”

“…More generally, we found a lower prevalence of NoV in our study compared to that reported in all previous studies from neighboring countries [33,37]. As observed elsewhere, GI strains were less frequently detected and had a higher diversity than GII genogroups [26,30,41]. The predominance of the GII.4 variants in this study may reinforce the hypothesis and emphasize the need to explore whether new GII.4 variants possibly arise in Africa where some of the GII.4 variants circulated earlier [24].…”

“…The presence of NoV and SaV was first screened using a single-step reverse transcription real time PCR as described previously [ 26 , 27 ]. In short, 10 µL mastermix containing Superscript TM III Platinum OneStep RT-qPCR System (Invitrogen, Karlsruhe, Germany) and 2 µL virus RNA extracted was used for the detection.…”

Virological and Epidemiological Features of Norovirus Infections in Brazil, 2017–2018

“…A larger GII genetic diversity was observed for both polymerase types and capsid genotypes compared to GI. The most predominant genotype detected was GII.4 Sydney[P16] followed by GII.2[P16] and GII.4 Sydney[P31], in agreement with several studies performed world-wide [ 18 , 19 , 54 , 61 , 62 , 63 , 64 , 65 ]. In 2017, we observed a high circulation of the GII.2[P16] at almost similar proportions of GII.4[P16].…”

“…In regard to age groups, we observed the highest prevalence of norovirus infections in children aged group from >6 to 24 months old. Several studies have demonstrated the peak of norovirus infection within the same age range [ 50 , 51 , 52 , 53 , 54 ]. Similar to our data, a study performed in Belém, Brazil, from 2012 to 2015 with children hospitalized with AGE, found the majority of norovirus-positive cases (72.7%) among the age group between 6 and 24 months old [ 29 ].…”