Emergence of Norovirus GII.4 variants in acute gastroenteritis outbreaks in South Korea between 2006 and 2013

BackgroundNew emerging strains of noroviruses (NoVs) often increase acute gastroenteritis (AGE) outbreaks worldwide.ObjectiveWe analyzed the epidemiological features and genotypic patterns of NoVs in AGE outbreaks.Study designTo elucidate the public health impact of NoVs during AGE outbreaks in South Korea, a molecular and epidemiological investigation was performed with 318 AGE outbreaks reported from the Gyeonggi province of South Korea during the period from 2006 to 2013.ResultsNoVs were associated with 102 (32.1%) of the AGE outbreaks. Epidemiological data revealed that the majority of NoV outbreaks were in the student group (47.1%), and the majority of AGE patients were identified in schools (68.8%). NoV genogroup (G) II strains were associated with 94 (92.2%) of the NoV outbreaks, and GII.4 strains were predominantly associated with 57.6% (n = 49) of NoV GII outbreaks. Four GII.4 variants (2006b, 2007, 2009 and 2012 variants) emerged and showed different contributions to NoV outbreak activity. The 2006b variant was predominantly associated with NoV outbreaks during the early years of the study period, and was subsequently displaced by the New Orleans 2009 variant, and most recently by the Sydney 2012 variant. In addition, the GII.2, GII.14, and GII.17 strains have recently been often associated with NoV AGE outbreaks.ConclusionsThe emergence of new NoV GII.4 variants significantly affected the NoV outbreak activity in South Korea during the period from 2006 to 2013. The surveillance for new emerging strains affecting NoV outbreak activity should be intensified to develop an adequate policy to prevent further NoV outbreaks.     

Epidemiological and molecular investigation of norovirus and astrovirus infections in Rio Branco,Acre, Northern Brazil: A retrospective study

Norovirus (NoV) is a major cause of nonbacterial acute gastroenteritis (AGE) outbreaks worldwide, with infections reported in semiclosed environments, particularly in hospitals and nursing homes. Astrovirus (HAstV) is prevalent worldwide, especially in developing countries. We aimed to determine the prevalence, spatial distribution, and genetic diversity of NoV and HAstV in children under 5 years of age in Rio Branco city, Acre State, Amazon Region, Brazil. Stool samples from children with (n = 240) and without (n = 248) AGE were collected from January to December 2012 from seven neighborhoods. The overall NoV prevalence was 12.3% (60 of 488); representing 15.8% (38 of 240) of the symptomatic samples and 8.9% (22 of 248) of the controls. HAstVs infection was observed in 4.7% (23 of 488) of the samples tested, 6.2% (15 of 240) of AGE cases, and 2.4% (6 of 248) of the controls (plus two without information about feces consistency). Infections were found in all age groups with higher frequency in children less than two years of age, for both viruses. NoV was detected in all neighborhoods, with a higher concentration in the fourth (30%; 18 of 60). NoV nucleotide sequencing performed in 86.7% (52 of 60) of the positive samples showed the circulation of the strains GII.4 (57.7%; 30 of 52), GIIPe/GII.4 (19.2%; 10 of 52), GII.7, GII.Pg/GII.1, and GII.Pc (3.8%; 2 of 52 for each), GII.6 and GII.Pg (1.9%; 1 of 52 for each), and GI.3 (7.7%; 4 of 52). Three GII.4 variants were detected: Den Haag_2006b (n = 1), New Orleans_2009 (n = 1), and Sydney_2012 (n = 14). HAstV types HAstV-1a (81.8%; 9 of 11) and HAstV-2c (18.2%; 2 of 11) were observed in the 47.8% (11 of 23) of characterized samples. This is the first data obtained in Acre State regarding the prevalence of these viruses and provides epidemiological and molecular information for a better understanding of their role among children with and without AGE.     

A duplex real-time RT-PCR assay for the simultaneous genogroup-specific detection of noroviruses in both clinical and environmental specimens

Norovirus (NoV) is the major etiological agent causing foodborne and waterborne outbreaks worldwide. We developed a novel duplex real-time quantitative RT-PCR assay designed for the simultaneous detection of and discrimination between NoV genogroups GI and GII, by targeting the short junction region between ORF1 and ORF2, with sensitivity and efficiency comparable to those of each simplex RT-PCR assay. This new duplex assay was evaluated against clinical stool (n = 82) and environmental (groundwater or surface water, n = 60) specimens from South Korea, and the results were compared with those of conventional RT-PCR (cRT-PCR) assays. The duplex assay detected more positive samples than did the cRT-PCR for both clinical (74 vs. 71) and, more strikingly, environmental (24 vs. 10) specimens. No cross-reactivity against specimens containing other enteric viruses such as rotavirus, adenovirus, and poliovirus were observed. These results suggest that this newly developed duplex real-time RT-PCR assay can be used for the sensitive and simultaneous genogroup-specific detection of NoV in both clinical and environmental specimens.     

Differences in clinical presentation between norovirus genotypes in nursing homes

BackgroundIn healthcare settings, norovirus (NoV) outbreaks are predominated by genotype II.4 (GII.4) strains. Periodically, new variants of GII.4 emerge, causing a temporary increase of outbreaks.ObjectivesTo study the relationship between symptoms and NoV genotype.Study designData of 49 nursing homes which were monitored for NoV outbreaks in the winter seasons of 2005/2006 and/or 2006/2007 were used.ResultsData on symptoms and duration of illness were available for 465 residents and 174 staff members from 28 NoV outbreaks. Genotype GII.4 was responsible for 21 outbreaks. Attack rates for residents seemed to be higher in GII.4 outbreaks compared to other genotypes. In outbreaks caused by GII.4, residents vomited more often than in outbreaks with other genotypes. They also had more often complaints of nausea, abdominal cramps, fever, and mucus in stool. The GII.4 2004 variant outbreaks showed higher percentages of nausea, stomach ache, and fever than outbreaks with the GII.4 2006a variant. Differences in duration of illness were not found. In nursing home staff, no clear differences were found between outbreaks caused by GII.4 and non-GII.4 NoVs.ConclusionsGenotype GII.4 was found to be related to more symptomatic disease, including more residents vomiting, and to a lesser extent, higher attack rates among residents.     

Norovirus GII.4 variant 2006b caused epidemics of acute gastroenteritis in Australia during 2007 and 2008

BackgroundOver the last decade, four epidemics of norovirus-associated gastroenteritis have been reported in Australia. These epidemics were characterized by numerous outbreaks in institutional settings such as hospitals and nursing homes, as well as increases in requests for NoV testing in diagnostic centers. During 2007 and 2008, widespread outbreaks of acute gastroenteritis were once again seen across Australia, peaking during the winter months.ObjectivesThe primary objective of this study was to characterize two winter epidemics of NoV-associated gastroenteritis in 2007 and 2008 in Australia. Following this, we aimed to determine if these epidemics were caused by a new GII.4 variant or a previously circulating NoV strain.Study designNoV-positive fecal samples (n = 219) were collected over a 2-year period, December 2006 to December 2008, from cases of acute gastroenteritis in Australia. NoV RNA was amplified from these samples using a nested RT-PCR approach targeting the 5′ end of the capsid gene, termed region C. Further, characterization was performed by sequence analysis of the RdRp and capsid genes and recombination was identified using SimPlot.ResultsFrom 2004 to 2008, peaks in the numbers of NoV-positive EIA tests from the Prince of Wales Hospital Laboratory correlated with the overall number of gastroenteritis outbreaks reported to NSW Health, thereby supporting recent studies showing that NoV is the major cause of outbreak gastroenteritis. The predominant NoV GII variant identified during the 2007–2008 period was the GII.4 pandemic variant, 2006b (71.51%, 128/179), which replaced the 2006a variant identified in the previous Australian epidemic of 2006. Four novel GII variants were also identified including the three GII.4 variants: NoV 2008, NoV Osaka 2007 and NoV Cairo 2007, and one novel recombinant NoV designated GII.e/GII.12.ConclusionThe increase in acute gastroenteritis outbreaks in 2007 and 2008 were associated with the spread of the NoV GII.4 variant 2006b.     

Genetic relatedness of noroviruses identified in sporadic gastroenteritis in children and gastroenteritis outbreaks in northern Alberta

We compared the proportion and genotype distribution of norovirus (NoV) identified in sporadic acute gastroenteritis in children younger than 7 years old with the NoV strains found in outbreaks from January 2003 through April 2004 in northern Alberta, Canada. Eight genogroup I (GI) and 133 GII NoV cases were detected in 1,166 cases of acute sporadic childhood gastroenteritis with a monthly detection rates varying from 6.0% to 20.4% and no sporadic gastroenteritis case in October 2003. Seventy-eight outbreaks (65%) tested positive for NoV during the study period with an obvious winter predominance and no NoV outbreaks in August, September, and October 2003. Three GI and 51 GII strains from the sporadic childhood gastroenteritis cases and seven GI and 37 GII strains from gastroenteritis outbreaks were sequenced and analyzed. Strains belonging to the GII.4 cluster predominated in outbreaks (68%) while the strains in sporadic childhood gastroenteritis demonstrated significant heterogeneity with the majority belonging to the GII.3 cluster (36%). Further analysis of NoV strains from 34 sporadic childhood gastroenteritis cases and 38 gastroenteritis outbreaks in chronologically and geographically related groups failed to demonstrate clear link between strains circulating in the setting of sporadic childhood gastroenteritis and those found in outbreaks.     

Emerging norovirus GII.4 2008 variant detected in hospitalised paediatric patients in South Africa

BackgroundNoroviruses (NoVs) are important enteric pathogens that cause gastroenteritis worldwide. The first documented NoV outbreaks in South Africa (SA) were described in 1993. The current NoV prevalence and circulating genotypes are unknown. SA lacks NoV outbreak reporting systems and therefore the number and impact of NoV infections is underestimated.ObjectivesThis study aimed to determine the prevalence and genetic diversity of NoV infections in hospitalised paediatric patients with gastroenteritis in SA during 2008.Study designStool specimens referred for virological analysis from hospitalised children ≤13 years, with gastroenteritis, were screened for rotavirus, human adenovirus and human astrovirus by enzyme immunoassay and for NoV genogroup I (GI), II (GII) and sapovirus by real-time RT-PCR. NoV strains were genotyped, and variants identified, based on sequence and phylogenetic analyses of the 5′ end or the full length of the capsid gene, respectively.ResultsRotavirus was the most prevalent virus detected in 24.2% (61/252) of specimens, followed by NoV in 14.3% (35/245) and adenovirus, astrovirus and sapovirus in 9.6%, 6.7% and 4% of specimens, respectively. NoVs were only detected in children ≤2 years. The GII NoVs (89%) predominated and eight types were identified with GII.4 (43%) detected most frequently. The emerging 2008 GII.4 variant represented 80% of the GII.4 strains.ConclusionsA diverse range of NoV genotypes were identified in hospitalised children with gastroenteritis. The 2008 GII.4 variant was the most frequently detected strain in the study. This is the first report of NoV GII.4 viruses in SA.     

Molecular detection and genetic diversity of norovirus in hospitalized young adults with acute gastroenteritis in Bahia,Brazil

The molecular epidemiology of a recent norovirus (NoV) outbreak in Brazil performed by comparative analysis with Genebank NoV sequences showed that the GII.4 strain was responsible for 72.5% of all NoV-positive cases (58/80). Other detected NoV strains included GII.3 (7/80; 8.8%) and GII.9 (8/80; 10%). This is the first outbreak reported in Bahia state, Brazil, during June-July of 2006, where NoV was identified as the principal etiologic agent in hospitalized young adults with acute gastroenteritis symptoms. These findings suggest that GII.4 is a predominant circulating genotype in NoV outbreaks in Brazil.     

The emergence of recombinant norovirus GII.12[P16] and predominance of GII.3[P12] strains in pediatric patients with acute gastroenteritis in Thailand, 2019–2020

Norovirus (NoV) and sapovirus (SaV) are important pathogens that cause acute gastroenteritis (AGE) in all age groups, commonly in children worldwide. Recently, a number of studies have reported a wide variety of NoV recombinant strains. This study aimed to investigate the distribution of NoV and SaV recombinant strains circulating in Chiang Mai, Thailand, during 2019–2020. One hundred and twenty-four NoV and seven SaV strains detected in children admitted to the hospital with AGE were included in this study. The partial RNA-dependent RNA-polymerase (RdRp)/VP1 regions of these NoV and SaV strains were analyzed by phylogenetic analysis, Simplot, and RDP software. Overall, eight recombination patterns of NoV were detected. NoV GII.4[P16] was the most common strain detected (39.1%), followed by GII.3[P12] (25.0%), GII.4[P31] (17.2%), and other recombinant strains were detected at a lower rate. NoV GII.12[P16] strains were detected for the first time in Thailand. For SaV, none of the recombinant strains was detected. All SaV strains, GI.1/GI.1, GI.2/GI.2, and GII.5/GII.5, exhibited VP1 genotype corresponded to RdRp genotype. In conclusion, this study demonstrates the distribution and diversity of NoV and SaV recombinant strains circulating in pediatric patients with AGE in Chiang Mai, during 2019–2020 with the emergence of NoV GII.3[P12] and GII.12[P16].     

Norovirus in feces and nasopharyngeal swab of children with and without acute gastroenteritis symptoms: First report of GI.5 in Brazil and GI.3 in nasopharyngeal swab

BackgroundNoroviruses (NoVs) are an important cause of acute gastroenteritis (AGE), worldwide.ObjectivesTo evaluate the frequency, viral load and molecular profile of NoV in fecal and nasopharyngeal swab samples from hospitalized children, and to determine children’s secretor status.Study designFrom May 2014 to May 2015, 219 children were included in the study, 96 with gastroenteric symptoms and 123 without gastroenteric symptoms. All fecal and nasopharyngeal swab samples were screened by TaqMan RT-qPCR duplex (GI/GII NoV) and quality samples were characterized by genomic sequencing.ResultsNorovirus positivity rate in feces was 15.4% in asymptomatic and 18.8% in the symptomatic group. The median viral loads in feces were 2.69 × 10⁸ GC/g and 4.32 × 10⁷ GC/g from children with or without AGE symptoms, respectively. In nasopharyngeal swab samples, the NoV positivity was 11.4% in symptomatic children, with a median viral load of 2.20 × 10⁷ GC/mL and 6.5% in asymptomatic children, with an average viral load of 1.73 × 10⁶ GC/mL. In only two cases NoV was detected in both samples. A considerable genomic variability was observed in feces, with six genotypes being detected, as follows: GII.4, GII.6, GI.3 and GII.3, GI.2 and GI.5. Two GI.3 was detected in nasopharyngeal swab.ConclusionsOur data reveal considerable NoV frequencies in both nasopharyngeal and fecal samples from symptomatic and asymptomatic children. Higher viral loads were detected in samples from AGE symptomatic children, when compared to asymptomatic children. High genomic variability was observed, with this being the first report of GI.5 NoV in Brazil and of GI.3 in nasopharyngeal swab samples.     

Molecular epidemiology and host genetics of norovirus and rotavirus infections in Portuguese elderly living in aged care homes

Norovirus (NoV) and rotavirus group A (RVA) are major agents of acute gastroenteritis worldwide. This study aimed to investigate their epidemiological profile in Portuguese elderly living in long-term care facilities and to assess the host genetic factors mediating infection susceptibility. From November 2013 to June 2015, 636 faecal specimens from 169 elderly, mainly asymptomatic, living in nursing homes in Greater Lisbon and Faro district, Portugal, were collected. NoV and RVA were detected by real-time polymerase chain reaction and NoV genotyped by phylogenetic analysis. NoV detection rate was 7.1% (12 of 169). Three GI.3 and one GII.6 strains were genotyped. RVA detection rate was 3.6% (6 of 169), exclusively in asymptomatic individuals. Host genetic factors associated with infection susceptibility were described on 250 samples by saliva-based enzyme-linked immunosorbent assays. The Lewis-negative phenotype was 8.8% (22 of 250) and the rate of nonsecretors was 16.8% (42 of 250). Association to NoV and RVA infection was performed in the subgroup of individuals (n = 147) who delivered both faecal and saliva samples. The majority of NoV- and RVA-positive individuals (90.9% and 83.3%, respectively) were secretor-positive, with Lewis B phenotype. In a subset of individuals, FUT2 and FUT3 genes were genotyped to assess mutations and validate the secretor and Lewis phenotypes. All sequenced nonsecretors were homozygous for FUT2 nonsense mutation G428A. In this study, low detection rates of NoV and RVA infections were found during two winter seasons. However, even in the absence of any outbreak, the importance of finding these infections in a nonepidemic situation in long-term care facilities may have important implications for infection control.     

Molecular Epidemiology of Genogroup II-Genotype 4 Noroviruses in the United States between 1994 and 2006

Human noroviruses (NoVs) of genogroup II, genotype 4 (GII.4) are the most common strains detected in outbreaks of acute gastroenteritis worldwide. To gain insight into the epidemiology and genetic variation of GII.4 strains, we analyzed 773 NoV outbreaks reported to the CDC from 1994 to 2006. Of these NoV outbreaks, 629 (81.4%) were caused by GII viruses and 342 (44.2%) were caused by GII.4 strains. The proportion of GII.4 outbreaks increased from 5% in 1994 to 85% in 2006, but distinct annual differences were noted, including sharp increases in 1996, 2003, and 2006 each associated with newly emerging GII.4 strains. Sequence analysis of the full-length VP1 gene of GII.4 strains identified in this study and from GenBank segregated these viruses into at least 9 distinct subclusters which had 1.3 to 3.2% amino acid variation between strains in different subclusters. We propose that GII.4 subclusters be defined as having >5% sequence variation between strains. Our data confirm other studies on the rapid emergence and displacement of highly virulent GII.4 strains.Noroviruses (NoVs), members of the genus Norovirus of the family Caliciviridae (13), are the leading cause of acute gastroenteritis (AGE) worldwide. In the United States, 81 to 96% of the nonbacterial AGE outbreaks with fecal specimens sent to the Viral Gastroenteritis Unit at the Centers for Disease Control and Prevention (CDC) were attributable to NoVs (4, 11, 12). In Europe, surveillance data from 10 countries demonstrated that >85% of all AGE outbreaks were associated with NoVs (22), and in Japan, NoV outbreaks were responsible for 93 to 97% of all viral gastroenteritis outbreaks (Infectious Disease Surveillance Center [IDSC], National Institute of Infectious Diseases [NIID] website http://idsc.nih.go.jp/iasr/iasrcnt-e.html#srsv-e).In the United States, NoVs account for an estimated 30 to 50% of all food-borne outbreaks (7a, 47). Norovirus outbreaks occur in a wide variety of settings year-round but are particularly common and protracted in the winter months in closed settings (e.g., hospitals and long-term care facilities [LTCFs]) where transmission is predominantly from person to person. Immunity to NoVs is poorly understood due to the lack of a cell culture system to measure neutralizing antibodies (9). Data from volunteer challenge studies demonstrate that immunity to NoVs seems to be short-term, and reinfections with heterogeneous and homologous strains have been documented (13). However, these conclusions are suspect because the challenge dose of virus used may have been 4 to 6 log₁₀ units higher than the infectious dose (39).NoVs have a 7.5- to 7.7-kb single-stranded genome of positive-sense RNA which contains three open reading frames (ORFs). ORF2 codes for the major capsid protein (VP1). NoVs are classified into five distinct genogroups (genogroup I [GI] to genogroup V [GV]) on the basis of VP1 sequencing analysis. These genogroups are further subdivided into at least 32 genetic clusters (13, 24, 44, 48). Of these, GI, GII, and GIV strains have been detected in humans, and viruses belonging to GII, genetic cluster or genotype 4 (GII.4) have emerged as the predominant strain over the last decade (4, 5, 10, 14, 15, 21, 23, 28, 33, 43, 46). The global distribution of a distinct GII.4 strain was first recognized in 1995 and 1996 (28). Between 1997 and 2002, NoV activity was moderate to low with different strains cocirculating without a distinct epidemic strain (6, 22). In 2002, 2004, and 2006, NoV outbreaks increased sharply and were associated with the emergence of new GII.4 strains (5, 7, 21, 46).To understand the epidemiologic patterns of GII.4 outbreaks in the United States and to determine the genetic variation of GII.4 NoV strains over time, we systematically analyzed NoV outbreaks and specimens reported to the CDC from 1994 to 2006.(This work was presented in part at the Third International Calicivirus Meeting, 10 to 13 November 2007, Cancun, Mexico, and at the 26th Annual Meeting of the American Society for Virology, 14 to 18 July 2007, Corvallis, OR.)     

Norovirus shedding among food and healthcare workers exposed to the virus in outbreak settings

BackgroundNoroviruses (NoV) are highly contagious and the leading cause of nonbacterial outbreaks of gastroenteritis worldwide. Individuals who are infected asymptomatically may act as reservoirs and facilitate the transmission of NoV, but the likelihood of workers of becoming infected in outbreak settings has not been systematically studied.ObjectivesWe evaluated the occurrence of norovirus infections among workers exposed to the virus in different outbreak settings.Study designWe screened feces from food handlers and healthcare workers related with gastroenteritis outbreaks, and shedding concentrations over time were calculated from serial samples of infected individuals. Sequence analyses of the capsid P2 domain and region C were used to evaluate linkage between asymptomatic employees and outbreak cases.ResultsOf all employees, 59.1% were positive for NoV, and more than 70% of them were asymptomatic. Asymptomatic infections were significantly more frequent in foodborne compared to person-to-person transmitted outbreaks; and in restaurants and hotels, compared to nursing homes and healthcare institutions. Mean viral loads were similar between symptomatic and asymptomatic individuals, starting at 7.51 ± 1.80 and 6.49 ± 1.93 log₁₀ genome copies/g, respectively, and decreasing to 5.28 ± 0.76 and 4.52 ± 1.45 log₁₀ genome copies/g after 19 days.ConclusionsThe likelihood of becoming infected when a NoV outbreak occurs at the work place is high and similar between food handlers and healthcare workers, but asymptomatic infections are more frequently identified among food handlers. Since shed amounts of viruses in the absence of symptoms are also high, reinforcement of hygiene practices among workers is especially relevant to reduce the risk of virus secondary transmissions.     

Genetic characterisation of Norovirus strains in outpatient children from rural communities of Vhembe district/South Africa, 2014–2015

BackgroundNorovirus (NoV) is now the most common cause of both outbreaks and sporadic non-bacterial gastroenteritis worldwide. However, data supporting the role of NoV in diarrheal disease are limited in the African continent.ObjectivesThis study investigates the distribution of NoV genotypes circulating in outpatient children from rural communities of Vhembe district/South Africa.Study designStool specimens were collected from children under five years of age with diarrhea, and controls without diarrhea, between July 2014 and April 2015. NoV-positive samples, detected previously by Realtime PCR, were analysed using conventional RT-PCR targeting the partial capsid and polymerase genes. Nucleotide sequencing methods were performed to genotype the strains.ResultsThe sequence analyses demonstrated multiple NoV genotypes including GI.4 (13.8%), GI.5 (6.9%), GII.14 (6.9%), GII.4 (31%), GII.6 (3.4%), GII.P15 (3.4%), GII.P21 (3.4%) and GII.Pe (31%). The most prevalent NoV genotypes were GII.4 Sydney 2012 variants (n = 7) among the capsid genotypes, GII.Pe (n = 9) among the polymerase genotypes and GII.Pe/GII.4 Sydney 2012 (n = 8) putative recombinants among the RdRp/Capsid genotypes. Two unassigned GII.4 variants were found.ConclusionsThe findings highlighted NoV genetic diversity and revealed continuous pandemic spread and predominance of GII.Pe/GII.4 Sydney 2012, indicative of increased NoV activity. An unusual RdRp genotype GII.P15 and two unassigned GII.4 variants were also identified from rural settings of the Vhembe district/South Africa. NoV surveillance is warranted to help to inform investigations into NoV evolution and disease burden, and to support on-going vaccine development programmes.     

High prevalence of enteric viruses associated with acute gastroenteritis in pediatric patients in a low-income area in Vitória,Southeastern Brazil

Acute gastroenteritis (AGE) is a significant cause of child mortality worldwide. In Brazil, despite the reduction in infant mortality achieved in recent years, many children still die because of undiagnosed AGE. The prevalence, viral load, and circulating genotypes of rotavirus A (RVA), human adenovirus (HAdV), and norovirus GII (NoV GII) were investigated in children with AGE during 12 months in Vitoria, Espírito Santo, Southeastern Brazil. Enteric viruses were detected in stool samples, quantified by quantitative polymerase chain reaction, sequenced, and compared phylogenetically. The overall prevalence was 93.3% (125/134). Cases of single infection (41.8%) and mixed infection (51.5%) were observed; in 21.6% of cases, all the three viruses were detected. RVA had the highest number of copies in all infections. Phylogenetic analysis revealed predominantly the presence of RVA genotype G3, followed by G2 and G9. HAdV clustered within subgroup C, but some samples harbored subgroups A, D, or F. All sequenced NoV-positive samples clustered within the prevalent genotype GII.4. The high prevalence of RVA, HAdV, and NoV in diarrheal feces clarifies the etiology of AGE in this population, and the presence of RVA in vaccinated children reinforces the importance of monitoring programs to identify the causes of gastroenteritis and contribute to the reliability of diagnosis.     

Synchronous whole-body vibration increases VO₂ during and following acute exercise

Single bout whole-body vibration (WBV) exercise has been shown to produce small but significant increases in oxygen consumption (VO₂). How much more a complete whole-body exercise session (multiple dynamic exercises targeting both upper and lower body muscles) can increase VO₂ is unknown. The purpose of this study was to quantify VO₂ during and for an extended time period (24 h) following a multiple exercise WBV exercise session versus the same session without vibration (NoV). VO₂ of healthy males (n = 8) was measured over 24 h on a day that included a WBV exercise session versus a day with the same exercise session without vibration (NoV), and versus a control day (no exercise). Upper and lower body exercises were studied (five, 30 s, 15 repetition sets of six exercises; 1:1 exercise:recovery ratio over 30 min). Diet was controlled. VO₂ was 23% greater (P = 0.002) during the WBV exercise session versus the NoV session (62.5 ± 12.0 vs. 50.7 ± 8.2 L O₂) and elicited a higher (P = 0.033) exercise heart rate versus NoV (139 ± 6 vs. 126 ± 11 bpm). Total O₂ consumed over 8 and 24 h following the WBV exercise was also increased (P < 0.010) (240.5 ± 28.3 and 518.9 ± 61.2 L O₂) versus both NoV (209.7 ± 22.9 and 471.1 ± 51.6 L O₂) and control (151.4 ± 20.7 and 415.2 ± 51.6 L O₂). NoV was also increased versus control (P < 0.003). A day with a 30-min multiple exercise, WBV session increased 24 h VO₂ versus a day that included the same exercise session without vibration, and versus a non-exercise day by 10 and 25%, respectively.