The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform
Mustafizur Rahman - One of the best experts on this subject based on the ideXlab platform.
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evolutionary history and global spread of the emerging g12 human Rotaviruses
Journal of Virology, 2007Co-Authors: Mustafizur Rahman, Koki Taniguchi, Jelle Matthijnssens, Thomas Delbeke, Xuelei Yang, Ingrid Arijs, Miren Iturrizagomara, N Iftekharuddin, Tasnim AzimAbstract:G12 Rotaviruses were first detected in diarrheic children in the Philippines in 1987, but no further cases were reported until 1998. However, G12 Rotaviruses have been detected all over the world in recent years. Here, we report the worldwide variations of G12 Rotaviruses to investigate the evolutionary mechanisms by which they managed to spread globally in a short period of time. We sequenced the complete genomes (11 segments) of nine G12 Rotaviruses isolated in Bangladesh, Belgium, Thailand, and the Philippines and compared them with the genomes of other rotavirus strains. Our genetic analyses revealed that after introduction of the VP7 gene of the rare G12 genotype into more common local strains through reassortment, a vast genetic diversity was generated and several new variants with distinct gene constellations emerged. These reassortment events most likely took place in Southeast Asian countries and spread to other parts of the world. The acquirement of gene segments from human-adapted Rotaviruses might allow G12 to better propagate in humans and hence to develop into an important emerging human pathogen.
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Sequence analysis and evolution of group B Rotaviruses.
Virus Research, 2007Co-Authors: Mustafizur Rahman, Sukalyani Banik, Marc Van Ranst, Jelle Matthijnssens, Zahid Hassan, Hasan Zafrul, Farjana Saiada, Abu Syed Golam Faruque, Thomas Delbeke, Tasnim AzimAbstract:Human group B Rotaviruses were isolated from hospitalized patients in Bangladesh between July 2003 and December 2004. Phylogenetic analyses of the gene segments encoding the hemagglutinin (VP4), glycoprotein (VP7) and RNA-binding protein (NSP2) of group B Rotaviruses showed that Bangladeshi strains were more similar to the Indian strains than to the prototype Chinese strains. Moreover, all human strains were clustered together and were distantly related to the animal strains. With limited sequence data, the evolutionary rate of the glycoproteins (VP7) of human group B Rotaviruses was estimated to be 1.57 × 10 −3 nucleotide substitutions/(site year), which was comparable to other rapidly evolving RNA viruses. The most recent common ancestor (MRCA) of the extant human group B Rotaviruses was calculated to date to around 1976.
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detection and characterization of human group c Rotaviruses in bangladesh
Journal of Clinical Microbiology, 2005Co-Authors: Mustafizur Rahman, Sukalyani Banik, Abu Syed Golam Faruque, Koki Taniguchi, David Allen Sack, Marc Van Ranst, Tasnim AzimAbstract:Group C Rotaviruses were detected by reverse transcription-PCR in 14 (2.3%) of 611 group A rotavirus-negative stool specimens from the patients admitted to the International Centre for Diarrhoeal Disease Research, Bangladesh hospital, Dhaka, Bangladesh, during July to December 2003. The low rate of detection suggested that infection with group C Rotaviruses was an uncommon cause of hospitalization due to gastroenteritis. In addition, coinfections with pathogenic enteric bacteria were frequently observed in group C rotavirus-infected patients. Nucleotide sequence comparison of the VP4, VP6, and VP7 genes revealed that the Bangladeshi group C Rotaviruses were most similar to Nigerian group C rotavirus strains. Phylogenetic analysis suggested that all human group C Rotaviruses, including the strains isolated in our study, clustered in a monophyletic branch, which was distantly related to the branch comprised of animal group C Rotaviruses.
Krisztián Bányai - One of the best experts on this subject based on the ideXlab platform.
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Molecular Epidemiology and Evolution of Rotaviruses
Viral Gastroenteritis, 2016Co-Authors: Krisztián Bányai, V.e. PitzerAbstract:Abstract We review the basic classification of Rotaviruses, as well as the mechanisms of rotavirus evolution and their significance. We then provide an overview of laboratory methods that have been used to characterize Rotaviruses since their discovery in the 1970s, and the role that these methods have played in our understanding of the molecular epidemiology of Rotaviruses. The global distribution of rotavirus genotypes, as well as, how these patterns vary over space and time, are described. Finally, we outline how our understanding of the transmission dynamics of rotavirus helps to explain the observed epidemiological trends.
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diversity and zoonotic potential of Rotaviruses in swine and cattle across europe
Veterinary Microbiology, 2012Co-Authors: Sofie Elisabeth Midgley, Krisztián Bányai, Javier Buesa, Nabil Halaihel, Charlotte Kristiane Hjulsager, Ferenc Jakab, Jeerome Kaplon, Lars Erik Larsen, Marina Monini, Mateja PoljsakprijateljAbstract:Abstract Group A Rotaviruses can infect both humans and animals. Individual rotavirus strains can occasionally cross species barriers and might hereby contribute to the emergence of new genotypes in heterologous hosts. The incidence and impact of zoonotic rotavirus are not well defined, and one reason for this is a lack of data about strains circulating in suspected reservoir animal hosts. In this study we report the incidence, genetic diversity, and molecular epidemiology of Rotaviruses detected in domestic cattle and swine in 6 European countries. From 2003 to 2007, 1101 and more than 2000 faecal specimens were collected from swine and cattle, both healthy and diarrhoeic, and tested for Rotaviruses. Viruses from positive stools were genotyped and a subset of strains was characterized by nucleotide sequencing and phylogenetic analysis of the VP7 (G) and VP4 (P) genes. Rotaviruses were detected in 43% of bovine samples and in 14% of porcine samples. In cattle, 10 different combinations of G and P types were identified and the most common strains were G6P[11] and G6P[5]. In swine, the number of identified G–P combinations was higher ( n = 21), however, no single combination was predominant across Europe. Newly described genotype specificities, P[27] and P[32], were identified in swine. When compared at the nucleotide sequence level, the identified porcine rotavirus strains and contemporary human strains grouped together phylogenetically, whereas bovine rotavirus strains formed separate clades. These data demonstrate large genetic diversity of porcine and bovine rotavirus strains across Europe, and suggest that livestock herds may serve as potential reservoirs for human infections.
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zoonotic aspects of Rotaviruses
Veterinary Microbiology, 2010Co-Authors: Vito Martella, Jelle Matthijnssens, Krisztián Bányai, Canio Buonavoglia, Max CiarletAbstract:Rotaviruses are important enteric pathogens of humans and animals. Group A Rotaviruses (GARVs) account for up to 1 million children deaths each year, chiefly in developing countries and human vaccines are now available in many countries. Rotavirus-associated enteritis is a major problem in livestock animals, notably in young calves and piglets. Early in the epidemiological GARV studies in humans, either sporadic cases or epidemics by atypical, animal-like GARV strains were described. Complete genome sequencing of human and animal GARV strains has revealed a striking genetic heterogeneity in the 11 double stranded RNA segments across different rotavirus strains and has provided evidence for frequent intersections between the evolution of human and animal Rotaviruses, as a result of multiple, repeated events of interspecies transmission and subsequent adaptation.
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prevalence of group c Rotaviruses in weaning and post weaning pigs with enteritis
Veterinary Microbiology, 2007Co-Authors: Vito Martella, Krisztián Bányai, S Arista, Eleonora Lorusso, Anna Lucia Bellacicco, Nicola Decaro, Michele Camero, Giancarlo Bozzo, P Moschidou, G PezzottiAbstract:Abstract Diarrheic fecal specimens collected from porcine herds were screened for the presence of group C Rotaviruses using a reverse transcription-polymerase chain reaction (RT-PCR) assay. A total of 188 samples were tested and 54 were positive. When compiled these data with diagnostic results on group A Rotaviruses and enteric caliciviruses we found that all but 5 group C rotavirus positive samples contained at least one additional virus. A subset of samples were subjected to nucleotide sequencing. The selected strains showed an unexpectedly wide range of nucleotide sequence heterogeneity (88.6–100%) to each other and to the reference porcine group C rotavirus strain, Cowden. The nucleotide sequence identity to the genuine bovine and human strains were, respectively, 86.8 and 87.2% or less. In conclusion, our study demonstrates that infection with group C rotavirus is frequent in Italian piggeries. The considerable rate of multiple infections requires further studies to investigate the pathogenic potential of group C Rotaviruses in pigs, alone or in mixed infection, and raises challenges in the laboratory diagnosis of porcine enteric infections.
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sequence analysis of the vp7 and vp4 genes identifies a novel vp7 gene allele of porcine Rotaviruses sharing a common evolutionary origin with human g2 Rotaviruses
Virology, 2005Co-Authors: Vito Martella, Krisztián Bányai, Max Ciarlet, Rafael Baselga, S Arista, Gabriella Elia, Eleonora Lorusso, Valentina Terio, A Madio, F M RuggeriAbstract:During an epidemiological survey encompassing several porcine herds in Saragoza, Spain, the VP7 and VP4 of a rotavirus-positive sample, 34461-4, could not be predicted by using multiple sets of G- and P-type-specific primers. Sequence analysis of the VP7 gene revealed a low amino acid (aa) identity with those of well-established G serotypes, ranging between 58.33% and 88.88%, with the highest identity being to human G2 Rotaviruses. Analysis of the VP4 gene revealed a P[23] VP4 specificity, as its VP8* aa sequence was 95.9% identical to that of the P14[23],G5 porcine strain A34, while analysis of the VP6 indicated a genogroup I, that is predictive of subgroup I specificity. Analysis of the 10th and 11th RNA segments revealed close identity to strains of porcine and human origin, respectively. The relatively low overall aa sequence conservation (<89% aa) to G2 human Rotaviruses, the lack of N-glycosylation sites that are usually highly conserved in G2 Rotaviruses, and the presence of several amino acid substitutions in the major antigenic hypervariable regions hampered an unambiguous classification of the porcine strain 34461-4 as G2 serotype on the basis of sequence analysis alone. The identification of a borderline, G2-like, VP7 gene allele in pigs, while reinforcing the hypotheses of a tight relationship in the evolution of human and animal Rotaviruses, provides additional evidence for the wide genetic/antigenic diversity of group A Rotaviruses.
Vito Martella - One of the best experts on this subject based on the ideXlab platform.
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Genomic evolution, host-species barrier, reassortment and classification of Rotaviruses
Future Virology, 2010Co-Authors: Jelle Matthijnssens, Vito Martella, Marc Van RanstAbstract:Evaluation of: Yamamoto D, Ghosh S, Ganesh B et al.: Analysis on genetic diversity and molecular evolution of human group B Rotaviruses based on whole genome segments. J. Gen. Virol. 91(Pt 7), 1772–1781 (2010). Rotaviruses are members of the Reoviridae family, causing severe diarrheal illness and death in humans and animals. They have been subdivided into at least seven serological groups (A–G), and, recently, a new rotavirus known as ‘new adult diarrhea virus’ or ADRV-N was discovered. Only in group A Rotaviruses have a substantial number of strains been analyzed completely on the molecular level. For groups B, C and ADRV-N Rotaviruses a very limited number of complete genomes are available, and for group D, E and F no sequence data are available at all. Here, Yamamoto and colleagues describe the full genomic characterization of four human group B Rotaviruses isolated in India, Bangladesh and Myanmar. These four strains were analyzed phylogenetically and individual gene segments were compared with their ...
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zoonotic aspects of Rotaviruses
Veterinary Microbiology, 2010Co-Authors: Vito Martella, Jelle Matthijnssens, Krisztián Bányai, Canio Buonavoglia, Max CiarletAbstract:Rotaviruses are important enteric pathogens of humans and animals. Group A Rotaviruses (GARVs) account for up to 1 million children deaths each year, chiefly in developing countries and human vaccines are now available in many countries. Rotavirus-associated enteritis is a major problem in livestock animals, notably in young calves and piglets. Early in the epidemiological GARV studies in humans, either sporadic cases or epidemics by atypical, animal-like GARV strains were described. Complete genome sequencing of human and animal GARV strains has revealed a striking genetic heterogeneity in the 11 double stranded RNA segments across different rotavirus strains and has provided evidence for frequent intersections between the evolution of human and animal Rotaviruses, as a result of multiple, repeated events of interspecies transmission and subsequent adaptation.
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prevalence of group c Rotaviruses in weaning and post weaning pigs with enteritis
Veterinary Microbiology, 2007Co-Authors: Vito Martella, Krisztián Bányai, S Arista, Eleonora Lorusso, Anna Lucia Bellacicco, Nicola Decaro, Michele Camero, Giancarlo Bozzo, P Moschidou, G PezzottiAbstract:Abstract Diarrheic fecal specimens collected from porcine herds were screened for the presence of group C Rotaviruses using a reverse transcription-polymerase chain reaction (RT-PCR) assay. A total of 188 samples were tested and 54 were positive. When compiled these data with diagnostic results on group A Rotaviruses and enteric caliciviruses we found that all but 5 group C rotavirus positive samples contained at least one additional virus. A subset of samples were subjected to nucleotide sequencing. The selected strains showed an unexpectedly wide range of nucleotide sequence heterogeneity (88.6–100%) to each other and to the reference porcine group C rotavirus strain, Cowden. The nucleotide sequence identity to the genuine bovine and human strains were, respectively, 86.8 and 87.2% or less. In conclusion, our study demonstrates that infection with group C rotavirus is frequent in Italian piggeries. The considerable rate of multiple infections requires further studies to investigate the pathogenic potential of group C Rotaviruses in pigs, alone or in mixed infection, and raises challenges in the laboratory diagnosis of porcine enteric infections.
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sequence analysis of the vp7 and vp4 genes identifies a novel vp7 gene allele of porcine Rotaviruses sharing a common evolutionary origin with human g2 Rotaviruses
Virology, 2005Co-Authors: Vito Martella, Krisztián Bányai, Max Ciarlet, Rafael Baselga, S Arista, Gabriella Elia, Eleonora Lorusso, Valentina Terio, A Madio, F M RuggeriAbstract:During an epidemiological survey encompassing several porcine herds in Saragoza, Spain, the VP7 and VP4 of a rotavirus-positive sample, 34461-4, could not be predicted by using multiple sets of G- and P-type-specific primers. Sequence analysis of the VP7 gene revealed a low amino acid (aa) identity with those of well-established G serotypes, ranging between 58.33% and 88.88%, with the highest identity being to human G2 Rotaviruses. Analysis of the VP4 gene revealed a P[23] VP4 specificity, as its VP8* aa sequence was 95.9% identical to that of the P14[23],G5 porcine strain A34, while analysis of the VP6 indicated a genogroup I, that is predictive of subgroup I specificity. Analysis of the 10th and 11th RNA segments revealed close identity to strains of porcine and human origin, respectively. The relatively low overall aa sequence conservation (<89% aa) to G2 human Rotaviruses, the lack of N-glycosylation sites that are usually highly conserved in G2 Rotaviruses, and the presence of several amino acid substitutions in the major antigenic hypervariable regions hampered an unambiguous classification of the porcine strain 34461-4 as G2 serotype on the basis of sequence analysis alone. The identification of a borderline, G2-like, VP7 gene allele in pigs, while reinforcing the hypotheses of a tight relationship in the evolution of human and animal Rotaviruses, provides additional evidence for the wide genetic/antigenic diversity of group A Rotaviruses.
Reimar Johne - One of the best experts on this subject based on the ideXlab platform.
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Distantly Related Rotaviruses in Common Shrews, Germany, 2004–2014
Emerging Infectious Diseases, 2019Co-Authors: Reimar Johne, Simon H. Tausch, Josephine Grützke, Alexander Falkenhagen, Corinna Patzina-mehling, Martin Beer, Dirk Höper, Rainer G. UlrichAbstract:We screened samples from common shrews (Sorex araneus) collected in Germany during 2004-2014 and identified 3 genetically divergent Rotaviruses. Virus protein 6 sequence similarities to prototype Rotaviruses were low (64.5% rotavirus A, 50.1% rotavirus C [tentative species K], 48.2% rotavirus H [tentative species L]). Shrew-associated Rotaviruses might have zoonotic potential.
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sequence analysis of the vp6 encoding genome segment of avian group f and g Rotaviruses
Virology, 2011Co-Authors: Reimar Johne, Peter Otto, Bernhard Roth, U Lohren, David M Belnap, Jochen Reetz, Eva TrojnarAbstract:Abstract Rotavirus groups A to E are mainly defined by antibody reactivity to the capsid protein VP6. Additionally, two putative rotavirus groups (F and G) have been identified in birds. Here, the first nucleotide sequences of the VP6-encoding genome segment of group F (strain 03V0568) and group G (strain 03V0567) Rotaviruses, both derived from chickens, are presented. The group F rotavirus is most closely related to avian group A and D Rotaviruses, with 49.9–52.3% nucleotide and 36.5–39.0% amino acid sequence identity. The group G rotavirus is most closely related to mammalian group B Rotaviruses, with 55.3–57.5% nucleotide and 48.2–49–9% amino acid sequence identity. The terminal sequences of the genome segment were similar in groups A, D and F, and in groups B and G. The findings indicate a long-term evolution of rotavirus groups in two separated clades and support the development of a sequence-based classification system for rotavirus groups.
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evidence of interspecies transmission and reassortment among avian group a Rotaviruses
Virology, 2009Co-Authors: Thomas Schumann, Helmut Hotzel, Peter Otto, Reimar JohneAbstract:Avian Rotaviruses are broadly distributed among birds, but only scarcely characterized on the molecular level. The VP4-, VP6-, VP7- and NSP5-encoding sequences of eight group A Rotaviruses from chickens and turkeys determined here indicate a low degree of sequence similarity with mammalian Rotaviruses. An NSP6-encoding region was missing in all chicken isolates except for isolate Ch2. Four novel genotypes (P[30], P[31], G22 and H8) were assigned by the Rotavirus Classification Working Group. Generally, chicken and turkey isolates clustered into separate branches of phylogenetic trees. However, chicken isolate Ch2 consistently clustered together with turkey isolates. Chicken isolate 06V0661G1 has a VP4-encoding sequence of unknown origin, but possesses VP6, VP7 and NSP5 genotypes typical for chicken isolates. These results might indicate interspecies transmission and reassortment among avian group A Rotaviruses under field conditions. PCR protocols enabling amplification of avian and mammalian group A Rotaviruses were developed for use in further epidemiological studies.
Timo Vesikari - One of the best experts on this subject based on the ideXlab platform.
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noroviruses as a major cause of acute gastroenteritis in children in finland 2009 2010
Scandinavian Journal of Infectious Diseases, 2011Co-Authors: Leena Puustinen, Sirpa Rasanen, Vesna Blazevic, Marjo Salminen, Minna Hamalainen, Timo VesikariAbstract:AbstractNoroviruses are, after Rotaviruses, the second most common cause of acute gastroenteritis in young children. In a prospective study conducted in 2009–2010 at the Tampere University Hospital, 195 stool specimens were collected from cases of acute gastroenteritis in children and examined for noroviruses, sapoviruses, and Rotaviruses, using a reverse transcriptase polymerase chain reaction (RT-PCR). Noroviruses were found in 49 (25%) of the cases and sapoviruses in 12 (6%). The norovirus genotype GII.4 dominated with a 76% share; other genotypes detected were GII.7/GII.6 (16%), GII.g/GII.12, GII.e/GII.4, and GII.7 (2% each). For comparison, 47 (24%) cases of rotavirus gastroenteritis were diagnosed in the same period. In conclusion, after the introduction of rotavirus vaccination in Finland in September 2009, noroviruses have become as common as Rotaviruses as the causative agents of acute gastroenteritis in young children, and are likely to become the leading cause. Norovirus GII.4 continues to be t...
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Noroviruses as a major cause of acute gastroenteritis in children in Finland, 2009–2010
Scandinavian Journal of Infectious Diseases, 2011Co-Authors: Leena Puustinen, Sirpa Rasanen, Vesna Blazevic, Marjo Salminen, Minna Hamalainen, Timo VesikariAbstract:AbstractNoroviruses are, after Rotaviruses, the second most common cause of acute gastroenteritis in young children. In a prospective study conducted in 2009–2010 at the Tampere University Hospital, 195 stool specimens were collected from cases of acute gastroenteritis in children and examined for noroviruses, sapoviruses, and Rotaviruses, using a reverse transcriptase polymerase chain reaction (RT-PCR). Noroviruses were found in 49 (25%) of the cases and sapoviruses in 12 (6%). The norovirus genotype GII.4 dominated with a 76% share; other genotypes detected were GII.7/GII.6 (16%), GII.g/GII.12, GII.e/GII.4, and GII.7 (2% each). For comparison, 47 (24%) cases of rotavirus gastroenteritis were diagnosed in the same period. In conclusion, after the introduction of rotavirus vaccination in Finland in September 2009, noroviruses have become as common as Rotaviruses as the causative agents of acute gastroenteritis in young children, and are likely to become the leading cause. Norovirus GII.4 continues to be t...
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Rotaviruses detected by reverse transcription polymerase chain reaction in acute gastroenteritis during a trial of rhesus human reassortant rotavirus tetravalent vaccine implications for vaccine efficacy analysis
Journal of Clinical Virology, 1999Co-Authors: Xiaoli Pang, Albert Z Kapikian, Yasutaka Hoshino, Jaana Joensuu, Timo VesikariAbstract:Background: Rotaviruses are routinely diagnosed by detection of rotavirus antigen in stools using an enzyme immunoassay (EIA). A sensitive method, like reverse transcription polymerase chain reaction (RT-PCR), may reveal more Rotaviruses, but the clinical significance of such findings is not well established. Objectives: To study whether RT-PCR can detect more episodes of rotavirus-associated gastroenteritis than EIA and to determine how rotavirus RT-PCR findings might change efficacy analysis of a rotavirus vaccine trial, in which the outcome measure was rotavirus gastroenteritis diagnosis with EIA. Study design: We applied RT-PCR for detection of Rotaviruses in gastroenteritis episodes encountered in an efficacy trial of rhesus-human reassortant rotavirus tetravalent (RRV-TV) vaccine, in a total of 2398 infants. During a follow-up, covering two rotavirus epidemic seasons, 256 cases of rotavirus associated gastroenteritis were detected by EIA; 226 were in the primary efficacy analysis period that included children who had received three doses of vaccine or placebo. Results: With RT-PCR, 84 (33%) more cases of rotavirus gastroenteritis were diagnosed than with EIA, 65 of these were in the primary efficacy analysis period. Clinically, cases of rotavirus gastroenteritis diagnosed by RT-PCR were much milder (median severity score 6 on a 20-point scale) than those diagnosed by EIA (median score 11), P<0.0001. RT-PCR revealed proportionally more G2 and G4 Rotaviruses than EIA. G1 Rotaviruses detected by RT-PCR were almost equally divided between RRV-TV (25) vaccine and placebo (28) groups, whereas an apparent vaccine protective effect was seen in the distribution of G2 (one in the RRV-TV and eight in the placebo group) and G4 Rotaviruses (six in the RRV-TV and 14 in the placebo group). Conclusion: RT-PCR is a useful tool in the diagnosis of rotavirus gastroenteritis, particularly for cases associated with other than the epidemiologically dominant G-type. Application of RT-PCR contributes to the overall appraisal of performance of rotavirus vaccine.
