Epidemiological and clinical insights into the enterovirus D68 upsurge in Europe 2021/22 and the emergence of novel B3-derived lineages, ENPEN multicentre study.

Enterovirus D68 (EV-D68) infections are associated with severe respiratory disease and acute flaccid myelitis (AFM). The European Non-Polio Enterovirus Network (ENPEN) aimed to investigate the epidemiological and genetic characteristics of EV-D68 and its clinical impact during the fall-winter season of 2021/22. From 19 European countries, 58 institutes reported 10,481 (6.8%) EV-positive samples of which 1,004 (9.6%) were identified as EV-D68 (852 respiratory samples). Clinical data was reported for 969 cases. 78.9% of infections were reported in children (0-5 years); 37.9% of cases were hospitalised. Acute respiratory distress was commonly noted (93.1%) followed by fever (49.4%). Neurological problems were observed in 6.4% of cases with six reported with AFM. Phylodynamic/Nextstrain and phylogenetic analyses based on 694 sequences showed the emergence of two novel B3-derived lineages, with no regional clustering. In conclusion, we describe a large-scale EV-D68 European upsurge with severe clinical impact and the emergence of B3-derived lineages.

Increased circulation of GII.17 noroviruses, six European countries and the United States, 2023 to 2024.

We report an increase in GII.17 norovirus outbreaks and sporadic infections of acute gastroenteritis in Austria, Germany, France, Ireland, the Netherlands, England and the United States during the 2023/24 season. A decrease in GII.4 coincided with GII.17 prevalence increasing to between 17% and 64% of all GII detections. Overall, 84% of the GII.17 strains clustered closely with strains first reported in Romania in 2021 and two new sub-lineages were identified. Norovirus surveillance and molecular characterisation should be prioritised this winter.

Dynamics of norovirus genotype change and early characterization of variants in children with diarrhea in central Tunisia, 2001-2012.

Human noroviruses (HuNoVs), especially GII.4 strains, are a major cause of gastroenteritis epidemics in both children and adults. Stool samples were collected from 113 Tunisian children with acute gastroenteritis in 2001 and 2002 and were retrospectively tested for HuNoVs. Fifteen (13.2%) of the 113 samples were positive for HuNoVs, all of which were genogroup II strains, and the GII.4-2004/Hunter variant was predominant (67%). We reconstituted the temporal circulation of HuNoV strains in central Tunisia between 2003 and 2012 using HuNoV isolates reported in our previous studies. A comparative analysis showed a dynamic change in the molecular profile of the HuNoV strains over a 12-year period. We found that GII.4-2004/Hunter strains were circulating as early as June 2002 and that GIX.1[GII.P15] HuNoVs were already circulating four years before this genotype was first reported in Japan in 2006. Our data suggest that epidemic strains of HuNoV circulate for several years in the pediatric population before becoming predominant. This study suggests that children from low-income countries with poor sanitation may play a significant role in the molecular evolution of noroviruses and the global emergence of new epidemic strains.

Prevalence and Genetic Diversity of Aichi Virus 1 from Urban Wastewater in Senegal.

Aichi virus 1 (AiV-1) has been proposed as a causative agent of human gastroenteritis. In this study, raw, decanted, and treated wastewater samples from a wastewater treatment plant in an urban area of Dakar, Senegal, were collected. AiV-1 was detected in raw (70%, 14/20), decanted (68.4%, 13/19), and treated (59.3%, 16/27) samples, revealing a noticeable resistance of AiV-1 to chlorine-based treatment. Phylogenetic analysis revealed that all sequences clustered within genotype B. Our study presents the first report on the detection of AiV-1 in the environment of Dakar and constitutes indirect evidence of virus circulation in the population.

Diagnostic Accuracy of Four Commercial Triplex Immunochromatographic Tests for Rapid Detection of Rotavirus, Adenovirus, and Norovirus in Human Stool Samples.

Noroviruses (NoV), rotaviruses (RVA), and adenoviruses (AdV) are the main viral agents responsible for acute gastroenteritis (AGE) in humans. We aimed to determine the diagnostic accuracy of four commercial immunochromatographic tests (ICTs) intended for the rapid and simultaneous detection of these three pathogens. Diagnostic accuracy of bioNexia Noro/Rota-Adeno (bioMérieux), Immunoquick NoRotAdeno (Biosynex), Rota+Adeno+Noro combo card (CerTest Biotec), and Rida Quick Rota/Adeno/Noro Combi (R-Biopharm) ICTs was assessed retrospectively using a collection of 160 stool specimens (including 43 RVA-, 47 AdV-, and 42 NoV-positive samples) from French patients with AGE and using molecular methods as the reference standard. For RVA, the four ICTs demonstrated similar high sensitivity (93%) and excellent specificity (97.4 to 100%). For AdV, the four ICTs demonstrated similar poor sensitivity (54.3 to 58.7%) but excellent specificity (95.5 to 100%). They performed the best in AdV-F species (sensitivity, 80.8 to 84.6%) and worst in AdV non-F species (sensitivity, 22.2 to 27.8%). For NoV, the Rida Quick Rota/Adeno/Noro combi ICT exhibited high sensitivity (87.5%), but the sensitivity of the three others was poor (42.5 to 47.5%). The four ICTs exhibited high specificity (96.6 to 99.1%). Diagnostic accuracy was genogroup dependent. When we tested genogroup I NoV, the Rida Quick Rota/Adeno/Noro Combi ICT presented high sensitivity (90%), while the three other ICTs presented poor sensitivity (10 to 30%); when we tested genogroup II NoV, sensitivity was similar for the four ICTs (65 to 85%). In conclusion, the four ICTs are suitable first-line tests for the rapid diagnosis of RVA infections. The four ICTs are not suitable for the routine diagnosis of AdV infections but could provide a rapid response in case of positivity, notably in the context of AGE. Only the Rida Quick Rota/Adeno/Noro Combi ICT is suitable for the rapid detection of NoV, while the sensitivity for the detection of genogroup I NoV needs to be improved for the 3 other ICTs before being implemented in the routine diagnosis of NoV.

Large concomitant outbreaks of acute gastroenteritis emergency visits in adults and food-borne events suspected to be linked to raw shellfish, France, December 2019 to January 2020.

On 27 December 2019, the French Public Health Agency identified a large increase in the number of acute gastroenteritis and vomiting visits, both in emergency departments and in emergency general practitioners' associations providing house-calls. In parallel, on 26 and 27 December, an unusual number of food-borne events suspected to be linked to the consumption of raw shellfish were reported through the mandatory reporting surveillance system. This paper describes these concomitant outbreaks and the investigations' results.

Molecular prevalence of bovine noroviruses and neboviruses in newborn calves in Iran.

In this study, bovine enteric caliciviruses (BECs) were detected in 49.4% of a total of 253 stool specimens for diarrheic calves collected from 42 industrial dairy farms from March 2010 to February 2012. Genogroup III norovirus (NoVsGIII) were more prevalent (39.5%) than neboviruses (NBs) (15%), and coinfections were observed in 5.1% of the samples tested. Sequence analysis of the partial polymerase gene from 13 NoVsGIII samples indicated the circulation of both genotype 1 and genotype 2 strains. Among the six NB strains sequenced, five were related to the Bo/Nebraska/80/US strain, while one was related to the Bo/Newbury1/76/UK strain.

Emergence of new recombinant noroviruses GII.p16-GII.4 and GII.p16-GII.2, France, 2016 to 2017.

An early increase in outbreaks of norovirus gastroenteritis characterised at the French National Reference Centre occurred this winter season. They were concurrent with an unusual pattern of circulating strains, with three predominant genotypes: the re-emergent variant GII.P4 2009-GII.4 2012 found in 28% of norovirus outbreaks and two new emergent recombinant strains GII.P16-GII.4 2012 and GII.P16-GII.2 never before observed in France, found in 24% and 14% of norovirus outbreaks, respectively.

Secular trends in incidence of acute gastroenteritis in general practice, France, 1991 to 2015.

We analysed 25 years of general practitioner (GP) visits for acute gastroenteritis (AG) surveillance in France, by the GP Sentinelles network. We searched for time trends of acute gastroenteritis incidence during winter periods. Data from emergency departments and drug reimbursement were additional data sources. A time-series analysis was performed using a generalised additive model for all data sources for the winter period. Virological data were incorporated and compared with the three data sources. The cumulative incidence of GP visits for winter AG exhibited an increasing trend from 1991 until 2008, when it reached 6,466 per 100,000 inhabitants. It decreased thereafter to 3,918 per 100,000 inhabitants in 2015. This decreasing trend was observed for all age groups and confirmed by the generalised additive model. For emergency department visits a decreasing trend was observed from 2004. Drug reimbursement data analyses demonstrated a decreasing trend from when data began in 2009. The incidence reported by GPs and emergency departments was lower following the emergence of norovirus GII.4 2012 (p < 0.0001). Winter AG incidences seem to follow long-term rising and decreasing trends that are important to monitor through continuous surveillance to evaluate the impact of prevention strategies, such as future immunisation against acute viral gastroenteritis.

The molecular epidemiology of bovine rotaviruses circulating in Iran: a two-year study.

Bovine group A rotavirus (bovine RVA) is recognized as a major cause of severe gastroenteritis in newborn calves. The purpose of this study was to estimate the prevalence and identify the genotypes of circulating bovine RVA in newborn diarrheic calves. Two hundred fifty-three stool samples of diarrheic calves up to 1 month old were collected from 42 industrial dairy farms in two Iranian provinces during March 2010 to February 2012. All collected samples were screened for the presence of bovine RVA by RT-PCR, and the G and P genotypes were determined by semi-nested multiplex RT-PCR assay. The results of RT-PCR indicated that 49.4 % (125 out of 253) of the samples were positive for bovine RVA. The G and P genotyping of a subset of positive samples (n = 85) by semi-nested multiplex RT-PCR revealed that G6 (55.3 %) and G10 (43.5 %) and P[5] (51.8 %) and P[11] (27 %) were the most prevalent G and P genotypes, respectively. G6P[5] was the dominant genotype (35.3 %), followed by G10P[5], G10P[11] and G6P[11], with prevalence rates of 16.5 %, 15.3 % and 10.6 %, respectively. Sequence analysis of 20 VP7 and four VP4 genes showed highest nucleotide sequence identity with the corresponding genes of strains RVA/Cow-tc/GBR/UK/1973/G6P7[5] and RVA/Cow-tc/USA/B223/XXXX/G10P[11]. The results of this study reveal the diversity of G and P genotypes in bovine RVA samples from diarrheic Iranian calves and expands our knowledge of bovine RVA infections in the Middle East. These results also highlight the importance of producing of an effective rotavirus vaccine and its inclusion in the national cattle immunization program.