Genotypes of rotavirus associated with acute gastroenteritis in Seoul, Korea

Acute viral gastroenteritis is one of the most common infectious diseases in infants and young children. Rotavirus is mainly important in childhood. The present study determined the detection rate, seasonality and G and P genotypes of rotaviruses in children hospitalized for acute gastroenteritis in Seoul, Korea in 2009. A total of 1,423 stool specimens were screened by ELISA for the presence of rotavirus antigens and the rotavirus-positive stools genotyped by RT-PCR. The G genotype was determined for 90% of samples (242/269) and the P genotype for 93.3% (251/269). During the study, 25 G-P combinations were detected with G1P[8] in 38.3% (n= 103) and G4P[6] in 5.9% (n= 16) cases. These data provided information on rotavirus in patients with acute gastroenteritis in Seoul, Korea and provided baseline data to motivate for the implementation of control measures for rotavirus disease.     

Microbiological and epidemiological aspects of rotavirus and enteric adenovirus infections in hospitalized children in Italy

Rotaviruses and enteric adenoviruses are the most important causative agents of acute infantile gastroenteritis worldwide. From July 2005 to June 2007, 445 stool specimens from pediatric patients hospitalized with acute diarrhea were collected and tested for the presence of rotaviruses and enteric adenoviruses using an immunochromatographic assay. Rotavirus infection was detected in 123 cases (27.6%, ranging from 31.7% in 2005-2006 to 24.2% in 2006-2007); adenovirus infection occurred in 17 cases (3.8%, 13 cases in 2005-2006 (6.3%) and 4 cases in 2006-2007 (1.7%). The highest prevalence was seen in children from 13 to 24 months for rotaviruses, and in children from 25 to 36 months for adenoviruses. Rotavirus infection was detected with significantly higher frequency in children up to 36 months old (32.0%) compared to the older children (19.9%) (P < 0.01). Mixed infections were observed in 10 cases (6 rotavirus-adenovirus, and 4 rotavirus-Salmonella spp.). Rotavirus infection was found predominantly in winter and spring with respect to autumn (P < 0.001) or summer (P < 0.05), with a peak in February. Adenovirus infection had a major epidemic period in spring 2006, peaking in March. Finally, this study indicates that many patients acquired rotavirus infection (37.4%), and enteric adenovirus infection (41.2%) during hospitalization for other underlying diseases.     

G and P genotypes of rotavirus circulating among children with diarrhea in the Colombian northern coast.

A study on the prevalence of rotavirus G and P genotypes was carried out based on 253 stool specimens obtained from children living in the Colombia northern coast region who were less than 3-years-old and who suffered from acute diarrhea. A previous study had detected the presence of rotavirus A in 90 (36.5%) of the 246 samples tested by enzyme immunoassay (EIA), and these strains were investigated in the present study. Of these, 50 strains yielded an RNA electropherotype, most of which (80.0%) had long profiles and 20.0% of which had short profiles. Genotyping of 84 positive samples indicated that 67.9% of the strains could be typed. G1 (57.9%), was the most predominant VP7 genotype, followed by G3 (21.1%), G9 (15.8%) and G2 (5.3%). Among the VP4 genotypes, P[4] (49.1%) was the most prevalent, followed by P[6] 36.4% and P[8] (14.5%). Neither G4 nor G8 nor P[9] types were detected. The most common G-P combinations were G3 P[4] (8.8%) and G9 P[6] (7.0%), followed by G1 P[4] and G1 P[8] (5.3% each). All G1 P[8] strains showed long RNA profiles, whereas G3 P[4] and G9 P[6] displayed both long and short patterns. Mixed infections involved 21.0% of strains. There was a marked diversity among strains collected, and novel strains, including G9, as well as other atypical combinations of G and P genotypes, such as G9 P[6] and G3 P[4], were found.     

Assessment of gastroenteric viruses frequency in a children's day care center in Rio De Janeiro, Brazil: a fifteen year study (1994-2008)

This 15-year study aimed to determine the role of the main viruses responsible for acute infantile gastroenteritis cases in a day care center in the city of Rio de Janeiro, Brazil. From 1994 to 2008, 539 fecal samples were obtained from 23 outbreaks as well as sporadic cases that occurred in this period. The detection of Rotavirus group A (RVA), norovirus (NoV) and astrovirus (AstV) was investigated both by classical and molecular methods of viral detection. RVA was detected by enzymatic immune assay and/or polyacrylamide gel electrophoresis and genotyped by using semi-nested multiplex PCR. NoV and AstV were subsequently tested by real time PCR in all RVA-negative samples and genotyped throughout genome sequencing. Three protocols for molecular characterization of NoV nucleotide sequencing were performed with the partial nucleotide sequencing of genomic regions known as region B (polymerase gen), C and D (capsid gen).Viruses were identified in 47.7% (257/539) of the cases, and the detection rates of RVA, NoV and AstV in16.1% (87/539), 33.4% (151/452), and 6.3% (19/301), respectively. Most gastroenteritis cases were reported in autumn and winter, although NoV presented a broader monthly distribution. Viruses' detection rates were significantly higher among children aged less than 24 months old, although NoV cases were detected in all age groups. RVA genotypes as G1P[8], G9P[8], G2P[4], G3P[8] and G1+G3P[8] and RVA was no longer detected after 2005. NoV characterization revealed genotypes variability circulating in the period as GI.2, GI.3, GI.8 GII.2, GII.3, GII.4, GII.4 variants 2001 and 2006b, GII.6, GII.7, GII.12 and GII.17. AstV genotypes 1, 2, 4 and 5 were also characterized. Those data demonstrate the impact of NoV infection in cases of infantile gastroenteritis, surpassing RVA infection responsible for high morbidity rate in children under five years old.     

Molecular epidemiology and clinical characterization of group A rotavirus infections in Tunisian children with acute gastroenteritis

Rotaviruses are the most common cause of severe viral gastroenteritis in early childhood worldwide. Thus, the objectives of our study were to determine the molecular epidemiology and the clinical features of rotavirus gastroenteritis in Tunisia. Between January 2003 and April 2007, a prospective study was conducted on 788 stool samples collected from children under 12 years of age who were suffering from acute gastroenteritis. Rotavirus was detected by multiplex RT-PCR in 27% (n = 213) of samples, among them 79.3% (n = 169) cases were monoinfections. The frequency of rotavirus infections was significantly higher among inpatients (29%) than among outpatients (13%) (P < 0.001). The seasonal distribution of rotavirus diarrhea showed a winter peak, with an unusual peak from June to September. The mean duration of hospitalization was 6.5 ± 8.1 days and the mean age was 15.8 ± 22.8 months for rotavirus monoinfections. Fever, vomiting, abdominal pain, and dehydration were observed in 88, 98, 13, and 80 cases, respectively, in children with rotavirus monoinfections. G3P[8] (45.6%) and G1P[8] (23.9%) were the most common genotypes found in our study. The determination of rotavirus infection prevalence and the characterization of the rotavirus strains circulating will help us to better understand the molecular biology and epidemiology of the disease in our country.     

Evidence of the co‐circulation of enteric viruses in sewage and in the population of Greater Cairo

Aims: To characterize major enteric viruses (enterovirus, rotavirus, norovirus, astrovirus and adenovirus) in the sewage of Greater Cairo and to compare the results with clinical data collected during the same period. Methods and Results: Seventy‐two sewage samples from two waste water treatment plants were collected from April 2006 through February 2007. Enteroviruses, noroviruses (NoVs) and rotaviruses (RVs) were detected by RT‐PCR in 22%, 18% and 8·3% of the samples, respectively. No adenovirus and astrovirus was detected. G2P[8], G9P[8], G1P[8], G2P[4] and rare G12 RV isolates were detected in the environment as well as a bovine RV. The environmental NoV strains mostly belonged to genogroup I (84%). Rotaviruses and some of the NoVs were similar to those found in the clinical samples at the same time. Conclusions: The comparison of environmental and clinical data suggests that similar RV and NoV isolates were circulating in the environment and in the population during the same period. Significance and Impact of the Study: Few studies have investigated the prevalence and the epidemiology of RVs and NoVs in Cairo. This work is the first to establish a correlation between viral gastroenteritis and the concomitant presence of enteric viruses in the environment for Greater Cairo where combined environmental and clinical surveys should help to prevent infections caused by these major pathogens.     

Reassortment in vivo: driving force for diversity of human rotavirus strains isolated in the United Kingdom between 1995 and 1999

The G and P genotypes of 3,601 rotavirus strains collected in the United Kingdom between 1995 and 1999 were determined (M. Iturriza-Gómara et al., J. Clin. Microbiol. 38:4394-4401, 2000). In 95.4% of the strains the most common G and P combinations, G1P[8], G2P[4], G3P[8], and G4P[8], were found. A small but significant number (2%) of isolates from the remaining strains were reassortants of the most common cocirculating strains, e.g., G1P[4] and G2P[8]. Rotavirus G9P[6] and G9P[8] strains, which constituted 2.7% of all viruses, were genetically closely related in their G components, but the P components of the G9P[8] strains were very closely related to those of cocirculating strains of the more common G types (G1, G3, and G4). In conclusion, genetic interaction by reassortment among cocirculating rotaviruses is not a rare event and contributes significantly to their overall diversity.     

Genotype distribution and evolutionary analysis of rotavirus associated with acute diarrhea outpatients in Hubei,China, 2013–2016

Group A human rotaviruses (RVAs) annually cause the deaths of 215,000 infants and young children. To understand the epidemiological characteristics and genetic evolution of RVAs, we performed sentinel surveillance on RVA prevalence in a rotavirus-surveillance network in Hubei, China. From 2013 to 2016, a total of 2007 fecal samples from hospital outpatients with acute gastroenteritis were collected from four cities of Hubei Province. Of the 2007 samples, 153 (7.62%) were identified positive for RVA by real-time RT-PCR. RVA infection in Hubei mainly occurred in autumn and winter. The highest detection rate of RVA infection was in 1–2 years old of outpatients (16.97%). No significant difference of RVA positive rate was observed between females and males. We performed a phylogenetic analysis of the G/P genotypes based on the partial VP7/VP4 gene sequences of RVAs. G9P[8] was the most predominant strain in all four years but the prevalence of G2P[4] genotype increased rapidly since 2014. We reconstructed the evolutionary time scale of RVAs in Hubei, and found that the evolutionary rates of the G9, G2, P[8], and P[4] genotypes of RVA were 1.069×10^-3, 1.029×10^-3, 1.283×10^-3 and 1.172×10^-3 nucleotide substitutions/site/year, respectively. Importantly, using a molecular clock model, we showed that most G9, G2, P[8], and P[4] genotype strains dated from the recent ancestor in 2005, 2005, 1993, and 2013, respectively. The finding of the distribution of RVAs in infants and young children in Hubei Province will contribute to the understanding of the epidemiological characteristics and genetic evolution of RVAs in China.     

2009～2010年北京儿童腹泻中轮状病毒新VP4基因亚型的研究

P[8]b基因亚型是国内外新近发现的A组人轮状病毒(HRV)VP4基因的一种新亚型,本研究旨在建立有效鉴别HRV P[8]a和P[8]b基因亚型及P[4]和P[6]基因型的VP4基因打点杂交分型方法,并运用此方法对2009～2010年首都儿科研究所附属儿童医院门诊及住院腹泻患儿中P[8]b基因亚型HRV的流行情况及其G/P基因组合情况进行研究。通过对GenBank序列数据库可检索到的国内外HRV各种P基因型及亚型的VP4基因序列应用相关软件进行基因分析,在不同基因型别间核苷酸变异密集而相同P基因型内核苷酸高度保守的的位置设计各型别探针,并分别以本实验室上传GenBank的北京HRV地方株P[4]和P[6]基因型及P[8]a和P[8]b亚型的VP4基因作为相应型别探针的合成引物的设计模板及探针经PCR合成的合成模板,合成地高辛素标记的DNA探针。经测序验证所建立的VP4基因杂交分型方法结果可靠。对门诊88例(55%,88/160)及住院79例(70.5%,79/112)HRV腹泻患儿的P分型结果显示P[8]a亚型仍为主要型别,前者为96.6%(85/88),而后者为62.0%(49/79);P[8]b亚型在住院HRV感染腹泻患儿中占较高比例(27.9%,22/79),虽然其在门诊HRV感染患儿中也存在,但仅占2.3%(2/88);另外单纯P[4]基因型HRV感染仅在住院腹泻患儿中检测到1例(1.3%,1/79),而P[6]基因型在门诊及住院HRV感染腹泻患儿中均未检测到;本组标本中HRV P[8]b亚型主要与G9基因型组合。本研究表明G9P[8]b型HRV在北京腹泻儿童中有流行。     

Reassortment of Human and Animal Rotavirus Gene Segments in Emerging DS-1-Like G1P[8] Rotavirus Strains

The emergence and rapid spread of novel DS-1-like G1P[8] human rotaviruses in Japan were recently reported. More recently, such intergenogroup reassortant strains were identified in Thailand, implying the ongoing spread of unusual rotavirus strains in Asia. During rotavirus surveillance in Thailand, three DS-1-like intergenogroup reassortant strains having G3P[8] (RVA/Human-wt/THA/SKT-281/2013/G3P[8] and RVA/Human-wt/THA/SKT-289/2013/G3P[8]) and G2P[8] (RVA/Human-wt/THA/LS-04/2013/G2P[8]) genotypes were identified in fecal samples from hospitalized children with acute gastroenteritis. In this study, we sequenced and characterized the complete genomes of strains SKT-281, SKT-289, and LS-04. On whole genomic analysis, all three strains exhibited unique genotype constellations including both genogroup 1 and 2 genes: G3-P[8]-I2-R2-C2-M2-A2-N2-T2-E2-H2 for strains SKT-281 and SKT-289, and G2-P[8]-I2-R2-C2-M2-A2-N2-T2-E2-H2 for strain LS-04. Except for the G genotype, the unique genotype constellation of the three strains (P[8]-I2-R2-C2-M2-A2-N2-T2-E2-H2) is commonly shared with DS-1-like G1P[8] strains. On phylogenetic analysis, nine of the 11 genes of strains SKT-281 and SKT-289 (VP4, VP6, VP1-3, NSP1-3, and NSP5) appeared to have originated from DS-1-like G1P[8] strains, while the remaining VP7 and NSP4 genes appeared to be of equine and bovine origin, respectively. Thus, strains SKT-281 and SKT-289 appeared to be reassortant strains as to DS-1-like G1P[8], animal-derived human, and/or animal rotaviruses. On the other hand, seven of the 11 genes of strain LS-04 (VP7, VP6, VP1, VP3, and NSP3-5) appeared to have originated from locally circulating DS-1-like G2P[4] human rotaviruses, while three genes (VP4, VP2, and NSP1) were assumed to be derived from DS-1-like G1P[8] strains. Notably, the remaining NSP2 gene of strain LS-04 appeared to be of bovine origin. Thus, strain LS-04 was assumed to be a multiple reassortment strain as to DS-1-like G1P[8], locally circulating DS-1-like G2P[4], bovine-like human, and/or bovine rotaviruses. Overall, the great genomic diversity among the DS-1-like G1P[8] strains seemed to have been generated through reassortment involving human and animal strains. To our knowledge, this is the first report on whole genome-based characterization of DS-1-like intergenogroup reassortant strains having G3P[8] and G2P[8] genotypes that have emerged in Thailand. Our observations will provide important insights into the evolutionary dynamics of emerging DS-1-like G1P[8] strains and related reassortant ones.     

Genetic Diversity of G3 Rotavirus Strains Circulating in Argentina during 1998–2012 Assessed by Full Genome Analyses

Seasonal shifts in the predominant strains and the periodic emergence of new strains are epidemiological features of human rotaviruses. After the sporadic detection in two samples in 1998, G3P[8] strains reemerged as the predominant rotavirus during 2008–2009 in Argentina. Notably, in 2011 6.3% (37/587) of samples presented the G3P[6] genotypes, which coincided with the recent detection of G3P[6] and G2P[6] strains in South America and Europe. Analyses of the 11 gene segments of four G3P[8] and two G3P[6] strains revealed that G3P[8] strains detected a decade apart (1998 and 2009) presented minor differences, while the G3P[6] strains presented a complete different genomic constellation albeit showing a similar VP7 gene. This study provides insights in the dynamics and evolution of one of the genotypes with the wider range of hosts and inter-species transmission potential.     

Detection and characterization of rotavirus G and P types from children participating in a rotavirus vaccine trial in Belém, Brazil

This study sought the characterization of rotaviruses in a trial with a tetravalent rhesus-human rotavirus vaccine in Belém, Brazil in children who received three doses of vaccine or placebo in the 1st, 3rd and 5th months of life. Rotavirus electropherotypes, subgroups, G serotypes, G, [P] and [P], G genotypes were determined in 93.3%, 95.9%, 93.3%, 73.3%, 95.5% and 92.2% of isolates, respectively. Serotypes G1, G2 and G4 were detected in 58.9%, 30% and 4.4% of the cases, respectively. Rotavirus genotype G5 was detected for the first time in Northern region in 4.4% of the infections. Rotavirus genotypes P[8], P[4], P[6] and P[8 + 6] were detected in 54.5%, 26.7%, 12.2%, and 2.2% of the cases, respectively. The predominant genotypes were P[8], G1 and P[4], G2 with 53% and 26.6% of the infections, respectively. Unusual strains accounted for 20.5% including P[4], G1, P[6], G1, P[6], G4, P[6], G5, P[8], G2, P[8], G5. Mixed infections involving P[8 + 6], G2 and P[8 + 6], G1 were also noted. The neonatal P[6] strains associated with diarrhea were detected among children aged 9-24 months. To our knowledge, this study represents the first in Brazil to analyse, on molecular basis, rotavirus genotypes from children participating in a rotavirus vaccine trial. These results are of potential importance regarding future rotavirus vaccination strategies in Brazil.