Molecular epidemiology of human group A rotavirus infections in the United Kingdom between 1995 and 1998

Molecular Characterization of Avian Rotaviruses F and G Detected in Brazilian Poultry Flocks

Avian rotaviruses (RVs) are important etiologic agents of gastroenteritis in birds. In general, avian RVs are understudied; consequently, there is a paucity of information regarding these viruses. Therefore, the characterization of these viral species is highly relevant because more robust information on genetic, epidemiologic, and evolutionary characteristics can clarify the importance of these infections, and inform efficient prevention and control measures. In this study, we describe partial genome characterizations of two avian RV species, RVF and RVG, detected in asymptomatic poultry flocks in Brazil. Complete or partial sequences of at least one of the genomic segments encoding VP1, VP2, VP4, VP6, VP7, NSP1, NSP4, NSP4, or NSP5 of 23 RVF and 3 RVG strains were obtained, and demonstrated that multiple variants of both RVF and RVG circulate among Brazilian poultry. In this study, new and important information regarding the genomic characteristics of RVF and RVG is described. In addition, the circulation of these viruses in the study region and the genetic variability of the strains detected are demonstrated. Thus, the data generated in this work should help in understanding the genetics and ecology of these viruses. Nonetheless, the availability of a greater number of sequences is necessary to advance the understanding of the evolution and zoonotic potential of these viruses.

Dynamics of G2P[4] strain evolution and rotavirus vaccination: A review of evidence for Rotarix

Rotavirus (RV) gastroenteritis is a vaccine-preventable disease that creates high medical and economic burden in both developed and developing countries. Worldwide, more than 100 countries have introduced RV vaccines in their national immunization programs, and the remarkable impact of reducing the burden of severe childhood gastroenteritis has been unequivocally demonstrated. Currently, 2 oral vaccines (Rotarix, GSK and RotaTeq, Merck) are widely utilized. Recent temporary increases in the relative prevalence of G2P[4] RV strains have been observed in countries implementing RV vaccination. This comprehensive literature review aims to provide an insight on RV genotype evolution in the context of mass vaccination with Rotarix, particularly in the case of G2P[4]. In the post-vaccine era, strain surveillance data indicated temporal and spatial changes in countries both with and without RV vaccination programs. Annual fluctuations in G2P[4] prevalence seem to occur naturally, with no substantial differences between countries using Rotarix, RotaTeq or mixed vaccination programs. Moreover, Rotarix has been shown to be efficacious and effective against gastroenteritis caused by non-vaccine strains, including G2P[4]. These data indicate that shifts in RV genotype distribution are likely to constitute an inherent process of virus evolution to infect the human gut. Following RV vaccine introduction, incidences of RV gastroenteritis declined dramatically and mass vaccination will likely maintain this status, despite possible fluctuations in the relative distribution of genotypes. There is no conclusive evidence of unusual burst of new or vaccine-escape strains since global RV vaccines use. The emergence of strains with a potential to increase the current burden of RV disease should be continuously monitored and can only be established by exhaustive characterization of strains, including whole genomic sequencing. Given the natural fluctuations in RV strains over time, caution is advised when interpreting temporal changes in RV strain dynamics, as they could mistakenly be attributed to vaccination.

Impact of rotavirus vaccination on rotavirus genotype distribution and diversity in England, September 2006 to August 2016

IntroductionRotavirus vaccination with the live-attenuated monovalent (a G1P[8] human rotavirus strain) two-dose Rotarix vaccine was introduced in England in July 2013. Since then, there have been significant reductions in rotavirus gastroenteritis incidence.AimWe assessed the vaccine's impact on rotavirus genotype distribution and diversity 3 years post-vaccine introduction.MethodsEpidemiological and microbiological data on genotyped rotavirus-positive samples between September 2006 and August 2016 were supplied by EuroRotaNet and Public Health England. Multinomial multivariable logistic regression adjusting for year, season and age was used to quantify changes in genotype prevalence in the vaccine period. Genotype diversity was measured using the Shannon's index (H') and Simpson's index of diversity (D).ResultsWe analysed genotypes from 8,044 faecal samples. In the pre-vaccine era, G1P[8] was most prevalent, ranging from 39% (411/1,057) to 74% (527/709) per year. In the vaccine era, G1P[8] prevalence declined each season (35%, 231/654; 12%, 154/1,257; 5%, 34/726) and genotype diversity increased significantly in 6-59 months old children (H' p < 0.001: D p < 0.001). In multinomial analysis, G2P[4] (adjusted multinomial odds ratio (aMOR): 9.51; 95% confidence interval (CI): 7.02-12.90), G3P[8] (aMOR: 2.83; 95% CI: 2.17-3.81), G12P[8] (aMOR: 2.46; 95% CI: 1.62-3.73) and G4P[8] (aMOR: 1.42; 95% CI: 1.02-1.96) significantly increased relative to G1P[8].ConclusionsIn the context of reduced rotavirus disease incidence, genotype diversity has increased, with a relative change in the dominant genotype from G1P[8] to G2P[4] after vaccine introduction. These changes will need continued surveillance as the number and age of vaccinated birth cohorts increase in the future.

Whole genomic analysis of human G8P[14] group A rotavirus detected from community gastroenteritis outbreak

Several suspected cases of zoonotic transmission of group A rotavirus (RVA)-related gastroenteritis were reported previously. In August 2012, G8P[14] RVA was detected in fecal specimens from a community gastroenteritis outbreak occurring during a school trip. In this study, additional analyses were performed and it was found that this strain had the G8-P[14]-I2-R2-C2-M2-A3-N2-T6-E2-H3 sequence, similar to bovine-like RVA strains. Some contamination by emesis and diarrheic feces was observed near a rest room in the lodging area. Contact history with animals was unknown in members of this school trip, and this case implied that the strain may have acquired the ability for person-to-person transmission.

Molecular characterisation and clinical correlates of rotavirus in children and adults in a tertiary care centre, Chennai, South India

AIMS

This study was undertaken to determine the rate of detection of rotavirus causing diarrhoea among children and adults, identify the common genotypes circulating and determine clinical correlates.

SETTINGS AND DESIGN

This is a cross-sectional study in a tertiary care centre.

MATERIALS AND METHODS

Stool samples were collected from adults and children, transported on ice, aliquoted and stored at - 80°C. Rotavirus antigen detection enzyme-linked immunosorbent assay was performed on all samples. Representative samples were typed by conventional hemi-nested VP7 and VP4 reverse transcription-polymerase chain reaction.

STATISTICAL ANALYSIS USED

Test of proportion, Student's t-test and Chi-square test were used for statistical analysis.

RESULTS

A total of 444 stool samples were collected and tested over 14 months. Among these, 116 were paediatric with a rate of positivity of 36.21% and 328 were adults with rate of positivity of 20.73%. Among children under 5 years (n = 90), the rate of positivity was 41.11%. Vesikari scale was used for clinical assessment. The mean ± standard deviation Vesikari score in rotavirus-infected children and rotavirus-uninfected children was 11.2 ± 3.2 and 8.9 ± 3.6, respectively, and the difference was statistically significant. Nineteen samples were genotyped in children < 5 years, 94.7% were of G1P[8] and 5.3% were of G9P[4] genotype. Genotyping of 14 adult samples, G1P[8](85.7%) was found as the predominant genotype, two samples (14.3%) were partially typed (G9PUT and G12PUT).

CONCLUSIONS

The rate of positivity of rotavirus in children under 5 years was 41.11%. G1P[8] is the most common strain circulating across all age groups.

High genetic diversity of species A rotaviruses detected in swine farms in Chile

Rotavirus A is one of the main causative agents of diarrhoea in lactating and weaned pigs worldwide. Its impact in the swine industry is well documented. However, in Chile, the current epidemiological status of rotavirus on porcine farms is unknown. This study evaluated the current epidemiologic status of rotavirus A infection in Chile using on-farm detection techniques, electrophoretic confirmation, genotyping and phylogenetic clustering by analysis of partial sequences of VP4 and VP7 genes. Rotavirus A was detected in four out of five farms with an overall prevalence of 17.7 % in diarrhoeic pigs. The average age of diarrhoea onset was at 32±6.2 days, corresponding to weaning pigs, and rotavirus was not detected in lactating piglets. Molecular characterization indicated that genotypes G5, G3, P[7] and P[13] are currently the most widely represented on these pigs farms. The phylogenetic analysis showed that farms shared similar G types (VP7), which might denote a common origin. Meanwhile, [P] types (VP4) showed considerable genetic diversity, and this might represent a high rate of reassortment of this genetic segment in rotavirus circulating in the researched area. These findings demonstrate the importance of considering both the geographical and production factors to accurately determine rotavirus prevalence status at the national level, and have relevant implications in determining effective strategies for rotavirus infection control on porcine farms.

Porcine Rotaviruses: Epidemiology, Immune Responses and Control Strategies

Rotaviruses (RVs) are a major cause of acute viral gastroenteritis in young animals and children worldwide. Immunocompetent adults of different species become resistant to clinical disease due to post-infection immunity, immune system maturation and gut physiological changes. Of the 9 RV genogroups (A–I), RV A, B, and C (RVA, RVB, and RVC, respectively) are associated with diarrhea in piglets. Although discovered decades ago, porcine genogroup E RVs (RVE) are uncommon and their pathogenesis is not studied well. The presence of porcine RV H (RVH), a newly defined distinct genogroup, was recently confirmed in diarrheic pigs in Japan, Brazil, and the US. The complex epidemiology, pathogenicity and high genetic diversity of porcine RVAs are widely recognized and well-studied. More recent data show a significant genetic diversity based on the VP7 gene analysis of RVB and C strains in pigs. In this review, we will summarize previous and recent research to provide insights on historic and current prevalence and genetic diversity of porcine RVs in different geographic regions and production systems. We will also provide a brief overview of immune responses to porcine RVs, available control strategies and zoonotic potential of different RV genotypes. An improved understanding of the above parameters may lead to the development of more optimal strategies to manage RV diarrheal disease in swine and humans.

Association of rotavirus strains and severity of gastroenteritis in Indian children

Rotavirus is the leading cause of severe and dehydrating diarrhea in children aged under 5 years. We undertook this hospital-based surveillance study to examine the possible relationship between the severity of diarrhea and the various G-group rotaviruses circulating in India. Stool samples (n = 2,051) were systematically collected from 4,711 children aged <5 years admitted with severe acute gastroenteritis to 12 medical school centers from April 2011 to July 2012. Rotavirus testing was undertaken using a commercially available enzyme immunoassay kit for the rotavirus VP6 antigen (Premier Rotaclone Qualitative ELISA). Rotavirus positive samples were genotyped for VP7 and VP4 antigens by reverse-transcription polymerase chain reaction at a central laboratory. Of the stool samples tested for rotavirus antigen, 541 (26.4%) were positive for VP6 antigen. Single serotype infections from 377 stool samples were compared in terms of gastroenteritis severity. Among those with G1 rotavirus infection, very severe diarrhea (Vesikari score ≥ 16) was reported in 59 (33.9%) children, severe diarrhea (Vesikari score 11–15) in 104 (59.8%), moderate (Vesikari score 6–10) and mild diarrhea (Vesikari score 0–5) in 11 (6.3%). Among those with G2 infection, very severe diarrhea was reported in 26 (27.4%) children, severe diarrhea in 46 (48.4%), and moderate and mild diarrhea in 23 (24.2 %). Among those with G9 infection, very severe diarrhea was reported in 47 (54.5%) children, severe diarrhea in 29 (33.6%), and moderate and mild diarrhea in 10 (11.9%). Among those with G12 infection, very severe diarrhea was reported in 9 (40.9%) children and severe diarrhea in 13 (59.1%). The results of this study indicate some association between rotavirus serotypes and severity of gastroenteritis.

Changing distribution of age, clinical severity, and genotypes of rotavirus gastroenteritis in hospitalized children after the introduction of vaccination: a single center study in Seoul between 2011 and 2014

Background

This study aimed to explore changes in clinical epidemiology and genotype distribution and their association among hospitalized children with rotavirus gastroenteritis after the introduction of vaccines.

Methods

Between November 2010 and October 2014, hospitalized children with acute gastroenteritis were enrolled. Rotavirus genotypes were confirmed through reverse transcription-polymerase chain reaction (RT-PCR), semi-nested PCR, and sequencing. Clinical information including vaccination status and the modified Vesikari scores were collected.

Results

Among 179 children with rotavirus infection, nineteen (10.6 %) were completely vaccinated. During the study period, the number of children between three and 23 months of age decreased significantly compared to the number of children older than 24 months of age (P = 0.010), who showed lower diarrhea severity (duration, P = 0.042; frequency, P = 0.021) but higher vomiting severity (P = 0.007, 0.036) compared to the former. Vaccination status was also significantly associated with lower vomiting severity after adjustment for age (frequency only, P = 0.018). The predominant genotypes were G2P[4] (18.4 %), G1P[8] (14.5 %), and G1P[4]P[8] (12.8 %), and the prevalence of genotypes with uncommon and mixed combinations was more than 50 %. Children infected with G2P[4] strains tended to be older (P = 0.005) and had more severe vomiting (P = 0.018, 0.006) than those with G1P[8].

Conclusions

Increase in age of infected, hospitalized children was accompanied by change in clinical severity during 2011–2014 after the introduction of vaccines in Seoul. Clinical severity was also associated with vaccination status and genotype. Long-term large scale studies are needed to document the significance of the increase in genotypes of uncommon and mixed combinations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1623-y) contains supplementary material, which is available to authorized users.

Prevalence and Genetic Diversity of Enteric Viruses in Children with Diarrhea in Ouagadougou, Burkina Faso

Enteric viruses are a major cause of diarrhea in children, especially those under five years old. Identifying the viral agents is critical to the development of effective preventive measures. This study aimed to determine the prevalence and genetic diversity of common enteric viruses in children under five years old in Burkina Faso. Stool samples from children with (n = 263) and without (n = 50) diarrhea disorders were collected in Ouagadougou, Burkina Faso from November 2011 to September 2012. Rotavirus, norovirus, sapovirus, astrovirus, adenovirus and Aichivirus A were detected using real-time or end-point (RT-)PCR. Rotavirus strains were G and P genotyped by multiplex RT-PCR and other viral strains were characterized by sequencing of viral subgenomic segements. At least one viral agent was detected in 85.6% and 72% of the symptomatic and asymptomatic patients, respectively. Rotavirus (63.5%), adenovirus (31.2%) and genogroup II norovirus (18.2%) were the most prevalent viruses in symptomatic patients, but only rotavirus and genogroup II norovirus were significantly associated with diarrhea (OR: 7.9, 95%CI: 3.7-17; OR: 3.5, 95%CI: 1-11.7, respectively). Sapovirus (10.3%), astrovirus (4.9%), genogroup I norovirus (2.7%) and Aichivirus A (0.8%) were less prevalent. The predominant genotype of rotavirus was G9P[8] (36.5%), and the predominant norovirus strain was GII.4 variant 2012 (71.4%). Among sapovirus, the genogroup II (87.5%) predominated. Astrovirus type 1 (41.7%) was the most frequent astrovirus identified. Aichivirus A belonged to the three genotypes (A, B and C). Enteric adenoviruses type 40 and 41 were identified in 10.2% and 5.1% respectively. Several cases of co-infections were detected. The results highlight the high prevalence and the high diversity of enteric viruses in Burkinabe children.

Community-Acquired Rotavirus Gastroenteritis Compared with Adenovirus and Norovirus Gastroenteritis in Italian Children: A Pedianet Study

Background. Rotavirus (RV) is the commonest pathogen in the hospital and primary care settings, followed by Adenovirus (AV) and Norovirus (NV). Only few studies that assess the burden of RV gastroenteritis at the community level have been carried out. Objectives. To estimate incidence, disease characteristics, seasonal distribution, and working days lost by parents of RV, AV, and NV gastroenteritis leading to a family pediatrician (FP) visit among children < 5 years. Methods. 12-month, observational, prospective, FP-based study has been carried out using Pedianet database. Results. RVGE incidence was 1.04 per 100 person-years with the highest incidence in the first 2 years of life. Incidences of AVGEs (1.74) and NVGEs (1.51) were slightly higher with similar characteristics regarding age distribution and symptoms. Risk of hospitalisation, access to emergency room (ER), and workdays lost from parents were not significantly different in RVGEs compared to the other viral infections. Conclusions. Features of RVGE in terms of hospitalisation length and indirect cost are lower than those reported in previous studies. Results of the present study reflect the large variability of data present in the literature. This observation underlines the utility of primary care networks for AGE surveillance and further studies on community-acquired gastroenteritis in children.

Rotavirus G2P[4] detection in fresh vegetables and oysters in Mexico City

Rotaviruses are the principal cause of dehydration caused by diarrhea in children younger than 2 years of age. Although these viral infections have mainly been associated with ingestion of fecally contaminated food and water, few studies have addressed the presence of the virus in food that is consumed raw or slightly cooked. In this work, 30 oyster samples and 33 vegetable samples were examined for the presence of rotavirus genotypes to evaluate their potential to produce gastrointestinal infections. The rotaviruses were identified by reverse transcriptase PCR amplification of the VP7 gene. G and P genotyping was also performed by reverse transcriptase PCR, with a detection sensitivity of up to 15 PFU/ml. Rotaviruses were found in 17 (26.9%) of 63 samples (10 oysters and 7 vegetables). The G2 genotype was found in 11 (64.7%) of 17 of the rotavirus strains, and 16 (94.1%) of 17 had the P[4] genotype. The combined genotypes found most frequently were G2P[4] (10 [58.82%] of 17), GNTP[4] (6 [35.29%] of 17), and G2P[NT] (1 [5.8%] of 17).

Epidemiology and genetic diversity of rotavirus strains in children with acute gastroenteritis in Lahore, Pakistan

Pakistan harbors high disease burden of gastro-enteric infections with majority of these caused by rotavirus. Unfortunately, lack of proper surveillance programs and laboratory facilities have resulted in scarcity of available data on rotavirus associated disease burden and epidemiological information in the country. We investigated 1306 stool samples collected over two years (2008–2009) from hospitalized children under 5 years of age for the presence of rotavirus strains and its genotypic diversity in Lahore. The prevalence rate during 2008 and 2009 was found to be 34% (n = 447 out of 1306). No significant difference was found between different age groups positive for rotavirus (p>0.05). A subset of EIA positive samples was further screened for rotavirus RNA through RT-PCR and 44 (49.43%) samples, out of total 89 EIA positive samples, were found positive. G and P type prevalence was found as follows: G1P [4] = 3(6.81%); G1P [6] = 9(20.45%); G1P [8] = 1(2.27%); G2P [4] = 21(47.72%); G2P [8] = 1(2.27%); G9P [4] = 1(2.27%); G9P [6] = 1(2.27%) and G9P [8] = 7(15.90%). Phylogenetic analysis revealed that the VP7 and VP4 sequences clustered closely with the previously detected strains in the country as well as Belgian rotaviruses. Antigenic characterization was performed by analyzing major epitopes in the immunodominant VP7 and VP4 gene segments. Although the neutralization conferring motifs were found variable between the Pakistani strains and the two recommended vaccines strains (Rotarix™ and RotaTeq™), we validate the use of rotavirus vaccine in Pakistan based on the proven and recognized vaccine efficacy across the globe. Our findings constitute the first report on rotavirus’ genotype diversity, their phylogenetic relatedness and epidemiology during the pre-vaccination era in Lahore, Pakistan and support the immediate introduction of rotavirus vaccine in the routine immunization program of the country.

Molecular characterization of group A rotavirus found in elderly patients in Ireland; predominance of G1P[8], continued presence of G9P[8], and emergence of G2P[4]

Rotavirus is a major cause of gastroenteritis in young children worldwide. There have been several recent reports concerning rotavirus isolation from adults, particularly in the elderly, presenting with gastroenteritis. In this study, the authors report on rotavirus outbreaks in five separate elderly care facilities between April, and June 2011 in Ireland. The following genotypes were detected; G1P[8] (n = 5/11), G2P[4] (n = 2/11), and G9P[8] (n = 2/11). Thus, similarities to previous reports were found in that G1P[8] predominated, G9P[8] was still detected but G2P[4] was detected for the first time in a geriatric population in Ireland. Here also described is the detection of Group 2 lineage IIC rotavirus in Ireland for the first time.

Rotavirus infection and its genetic characterization in non-hospitalized adults with acute gastroenteritis in Shanghai, China

Rotavirus is a major cause of acute gastroenteritis in infants and young children, while its role as a pathogen in adults has long been underappreciated. In order to describe the epidemiological patterns and genetic characteristics of rotavirus causing sporadic acute gastroenteritis in adults, hospital-based surveillance of rotavirus infections was conducted in Shanghai, China, between June 2010 and May 2011. Stool specimens were collected from outpatients with acute gastroenteritis admitted to three local hospitals. Rotavirus was detected using a colloidal gold test device. G and P genotyping were performed by multiplex PCR assays, and the VP7 gene of G9 strains were sequenced for further genetic characterization. Of 1,479 adult diarrheal stool samples examined during the 1-year surveillance period, 138 (9.3 %) were found to be rotavirus positive. G1 appeared to be the predominant genotype (35.5 %), suggesting a shift from genotype G3 to G1 in the study population in Shanghai. Meanwhile, a high frequency of genotype G9 (27.5 %) was also observed, and G9 was also predominant (38.1 %) in the small number of children (n=123) involved in the present study. Other specificities detected in adults were G2 (12.3 %) and G3 (13.8 %). For P genotyping, only two types, P[8] and P[4], were detected. P[8] was dominant in both children and adults. Sequence and phylogenetic analysis revealed that these strains could be divided into two different groups, with clustering within G9 lineage 3 and the subcluster of Japanese and Chinese G9 strains, respectively. In comparison to the previous data, G9 strains established themselves in a short time span as an important genotype in Shanghai, China.

Multiplex real-time PCR assays for the detection of group C rotavirus, astrovirus, and Subgenus F adenovirus in stool specimens

Group C rotavirus (GCRV), astrovirus (AstV), and adenovirus (subgenus F AdenoV) are etiologic agents of acute nonbacterial gastroenteritis, which often represents community outbreaks. For the efficient detection of GCRV, AstV, and subgenus F AdenoV in stool specimens, a multiplex real-time PCR assay was developed to detect these three viruses simultaneously, with high sensitivity and specificity. In total, 8404 clinical specimens were collected between April 2008 and March 2011 and tested for GCRV, AstV, and subgenus F AdenoV by the multiplex real-time PCR, as well as for norovirus (NoV), sapovirus (SaV), and group A rotavirus (GARV) by non-multiplex real-time PCR. Forty-one specimens were positive for GCRV, AstV, or subgenus F AdenoV, including 15 specimens that were also positive for NoV, SaV, or GARV. Multiple viruses were detected simultaneously in 29 out of 4596 (0.63%) specimens infected with at least one virus. The association rates of AstV and subgenus F AdenoV with other viruses were significantly higher than those of NoV, SaV, GARV, or GCRV.

Complete genetic characterization of human G2P[6] and G3P[6] rotavirus strains

During the 2008-2009 rotavirus season, 10 G3P[6] rotavirus strains were isolated for the first time in Belgium, while an outbreak of G2P[6] strains occurred in the USA in 2005-2006. Partial sequencing of the 11 genome segments of the 10 Belgian G3P[6] strains revealed a clonal origin. Two of these strains, and a G2P[6] strain representative of the American outbreak, were selected and sequenced completely to analyze their evolutionary relationships. Genetic analysis revealed that all strains possessed a DS-1-like genotype constellation. The 2 Belgian G3P[6] strains showed >99% sequence identity at the nucleotide level and the American G2P[6] strain was phylogenetically closely related to the Belgian P[6] strains. These data suggest that reassortment(s) involving VP7 occurred recently, and that the prevalence of DS-1-like P[6] rotavirus strains need to be closely monitored because the currently licensed RVA vaccines contain neither the P[6] genotype nor strains with a complete human DS-1 genotype constellation.

Enteric pathogens through life stages

Enteric infections and diarrheal diseases constitute pervasive health burdens throughout the world, with rates being highest at the two ends of life. During the first 2–3 years of life, much of the disease burden may be attributed to infection with enteric pathogens including Salmonella, rotavirus, and many other bacterial, viral, and protozoan organisms; however, infections due to Clostridium difficile exhibit steady increases with age. Still others, like Campylobacter infections in industrialized settings are high in early life (<2 years old) and increase again in early adulthood (called the “second weaning” by some). The reasons for these differences undoubtedly reside in part in pathogen differences; however, host factors including the commensal intestinal microbial communities, immune responses (innate and acquired), and age-dependant shifts likely play important roles. Interplay of these factors is illustrated by studies examining changes in human gut microbiota with inflammatory bowel disease and irritable bowel syndrome. Recent gut microbial surveys have indicated dramatic shifts in gut microbial population structure from infants to young adults to the elders. An understanding of the evolution of these factors and their interactions (e.g., how does gut microbiota modulate the “inflamm-aging” process or vice versa) through the human life “cycle” will be important in better addressing and controlling these enteric infections and their consequences for both quality and quantity of life (often assessed as disability adjusted life-years or “DALYs”).

[Comparison of clinical characteristics of patients with rotavirus gastroenteritis relative to the infecting rotavirus g-p genotype.]

BACKGROUND

Group A rotavirus is a major cause of severe diarrhea in children throughout the world. For the proper management of rotavirus infections, it will be helpful to know their clinical characteristics according to the G and P genotypes of the infecting virus.

METHODS

The diarrheal stool specimens from patients hospitalized in Chosun University Hospital during 2002-2003 were tested for rotavirus by Dipstick 'Eiken' Rota kit. Rotavirus antigen-positive stool specimens were analyzed for group A rotavirus by RT-PCR, and the group A-positive PCR products were genotyped for P and G types by PCR.

RESULTS

Among the 119 specimens analyzed for genotypes, the predominant strain was genotype G4P[6] (51.3%), followed by G2P[4] (19.3%), G1P[8] (7.6%), G3P[8] (5.0%), and G9P[8] (4.2%). To examine the characteristics of each rotavirus genotype, a clinico-epidemiological study was performed for 100 patients whose medical records were available. The frequencies of diarrhea, vomiting, dehydration, and fever; the rates of nosocomial infection and transfer from other hospitals; and the mean severity scores were significantly different among the patients infected with different types of rotavirus. Especially, patients with G4P[6] type were more likely than those infected with other genotypes to show the following distinct features: Most patients showed milder symptoms and were neonates transferred from other obstetric hospitals and 68.4% of the cases were nosocomial infection. G4P[6] strains were isolated almost all along the year. The mean severity scores of patients infected by G4P[6], G2P[4], G1P[8], G3P[8], and G9P[8] strains were 6.8, 9.5, 8.0, 9.0, and 10.8, respectively.

CONCLUSIONS

Many features of rotavirus infections including the epidemic period, rate of nosocomial infection, age and severity of symptoms were different according to the genotypes of the infecting virus.

Burden of community-acquired and nosocomial rotavirus gastroenteritis in the pediatric population of Western Europe: a scoping review

BACKGROUND

Rotavirus affects 95% of children worldwide by age 5 years and is the leading cause of severe dehydrating diarrhea. The objective of this review was to estimate the burden of rotavirus gastroenteritis (RVGE) in the Western European pediatric population.

METHODS

A comprehensive literature search (1999-2010) was conducted in PubMed and other sources (CDC; WHO, others). Data on the epidemiology and burden of RVGE among children < 5 years-old in Western Europe --including hospital-acquired disease--were extracted.

RESULTS

76 studies from 16 countries were identified. The mean percentage of acute gastroenteritis (AGE) cases caused by rotavirus ranged from 25.3%-63.5% in children < 5 years of age, peaking during winter. Incidence rates of RVGE ranged from 1.33-4.96 cases/100 person- years. Hospitalization rates for RVGE ranged from 7% to 81% among infected children, depending on the country. Nosocomial RVGE accounted for 47%-69% of all hospital-acquired AGE and prolonged hospital stays by 4-12 days. Each year, RVGE incurred $0.54- $53.6 million in direct medical costs and $1.7-$22.4 million in indirect costs in the 16 countries studied. Full serotyping data was available for 8 countries. G1P[8], G2P[4], G9P[8], and G3P[8] were the most prevalent serotypes (cumulative frequency: 57.2%- 98.7%). Serotype distribution in nosocomial RVGE was similar.

CONCLUSIONS

This review confirms that RVGE is a common disease associated with significant morbidity and costs across Western Europe. A vaccine protecting against multiple serotypes may decrease the epidemiological and cost burden of RVGE in Western Europe.

Evaluation of a multiplex real time reverse transcription PCR assay for the detection and quantitation of the most common human rotavirus genotypes

Group A rotaviruses (RVs) are important pathogens that cause acute, dehydrating gastroenteritis in infants and young children. In this study, a multiplex real-time polymerase chain reaction protocol using primers and TaqMan(®) probes specific for viral VP4 and VP7 genes was evaluated. This assay offers simultaneous genotyping and quantification of the most common RV genotypes G1P[8], G2P[4], G3P[8], G4P[8], and G9P[8]. It was compared to the molecular typing results provided by conventional PCR. A total of 92 archived stool specimens obtained from children younger than 5 years old with the diagnosis of acute gastroenteritis were examined. Real-time PCR assay detected rotavirus strains among the most common genotype combinations G4P[8] (70.7%), G1P[8] (10.9%), G2P[4] (5.4%), G9P[8] (2.2%). This new assay described has an acceptable sensitivity (low limit 6.3×10(2)copies/g of stool).

Emergence of G9 as a predominant genotype of human rotaviruses in Cuba

To study human rotaviruses in Cuban children up to 5 years old with acute diarrhea, a total of 64 faecal samples from two pediatric hospitals between 2006 and 2008 were analyzed. Thirty-nine samples (60.9%) were found positive for rotaviruses by enzyme-linked immunosorbent assay (ELISA) and polyacrylamide gel electrophoresis (PAGE), while four (6.2%) exhibited discordant results (ELISA positives/PAGE negatives). All the positive samples were genotyped by a reverse transcription-polymerase chain reaction (RT-PCR). The most prevalent G and P types were G1 (60.5%) and P[8] (90.6%), respectively. Among the rotaviruses detected, two long RNA patterns were identified by PAGE (L/A and L/B). The predominant genotype in 2006 and 2007 was G1/P[8] with detection rates 71.4% and 80%, respectively. In contrast, G9/P[8] was found at the highest rate (78.5%) in 2008. The phylogenetic analysis of VP7 genes of the ten representative strains indicated that Cuban G1/P[8] rotaviruses were close to those reported in the Americas, and G9/P[8] rotaviruses were located in the lineage of the emerging G9 strains spreading worldwide. This is the first molecular epidemiologic study of rotaviruses in Cuba, highlighting the current increase of the G9 rotavirus which has been recognized globally as an emerging genotype. The study reinforces the need for a systematic surveillance of the molecular epidemiology of rotaviruses.

Burden of rotavirus gastroenteritis in the pediatric population in Central and Eastern Europe: serotype distribution and burden of illness

BACKGROUND

Rotaviral gastroenteritis (RVGE) is the leading cause of severe diarrhea in children under five years of age worldwide. This comprehensive review aims to estimate the burden of RVGE among children in Central and Eastern Europe.

METHODS

An extensive search of the biomedical literature (1999-2009) was conducted in major databases. Studies pertaining to the epidemiology and burden of rotavirus in Central and Eastern Europe were captured and data from each country was systematically extracted and compared.

RESULTS

This literature search captured 38 studies pertaining to RVGE infection in the region. Among children under 15 years of age, RVGE accounted for between 22.0% and 55.3% of all cases of acute gastroenteritis per year. For most countries RVGE was most common in the winter months, although it was reported year round in Bulgaria. Geographical comparison of genotyping data revealed that three genotype combinations, G1P[8], G4P[8], and G2P[4] were present in all countries for which full genotyping data was available. Genotype predominance varied on a season to season basis within each country. Only limited data was available for healthcare resource utilization, and economic burden for this region.

CONCLUSIONS

RVGE is a common disease associated with significant morbidity, and mortality. While three genotype combinations currently predominate in the region, the dominance of a certain serotype can change dramatically from year to year and from country to country. A vaccination program with broad serotype coverage may help to decrease the burden of RVGE in Central and Eastern Europe.

Emergence of human rotavirus genotype G9 in metropolitan Detroit between 2007 and 2009

Between January 2007 and April 2009, rotavirus (RV)-positive stool samples from 238 children with acute gastroenteritis, seen at Children's Hospital of Michigan in Detroit, USA, were collected and RV genotyping was performed. G and P genotypes were determined by RT-PCR and nucleotide sequencing was conducted on selected G9 and P[6] strains. Correlation between the severity of gastroenteritis episode and the infecting G genotype was done using a 14-point scoring system. The predominant G genotype was G9 (39.5 %), followed by G1 (35.3 %) and G4 (15.5 %), while P[8] was the most prevalent P genotype (66.5 %), followed by P[4] (21.9 %) and P[6] (11.2 %). The gene combinations G1P[8] and G9P[8] were the most prevalent (21.4 % and 20.6 %, respectively), followed by G4P[8] (13 %) and G9P[6] (8.8 %). Immunization data showed that only 17/238 (7.1 %) children received ≥one dose of RV vaccine (the pentavalent vaccine RotaTeq or the monovalent vaccine Rotarix) and that 10/17 were infected with G4P[8] strains. Severity of RV gastroenteritis episodes was not related to the infecting G genotype. Our results suggest a high proportion of genotype G9 strains in combination with P[8], P[6] and P[4] specificity circulating in the metropolitan Detroit area. While the protective efficacy of the RV vaccines has been demonstrated against G9P[8] strains, the level of cross-protection offered by the vaccines against G9 strains with P[6] and P[4] genotypes in the Detroit paediatric population remains to be determined.

Molecular and clinical characterization of rotavirus from diarrheal infants admitted to pediatric emergency units in france

BACKGROUND

rotaviruses are the major cause of acute gastroenteritis in young children worldwide, and require careful surveillance, especially in the context of vaccination programs. Prospective surveillance is required to monitor and characterize rotavirus infections, including viral and clinical data, and to detect the emergence of potentially epidemic strains.

METHODS

between 2006 and 2009, stool samples and clinical records were collected from 2044 children with acute diarrhea admitted to the pediatric emergency units of 13 French university hospitals. Rotaviruses were detected in stools, then genotyped by reverse transcription-polymerase chain reaction with regard to their outer capsid proteins VP4 and VP7.

RESULTS

the genotyping of 1947 rotaviruses showed that G1 (61.7%) and G9 (27.4%) strains were predominant and stable, followed by G2 (6.5%), G3 (4.0%), and G4 (2.5%) strains. Most strains were associated with P[8] (92.9%). Overall, 31 uncommon strains and possible zoonotic reassortants were detected including G12 and G8 strains, some being closely related to bovine strains. No difference in clinical presentation and severity was found among genotypes.

CONCLUSIONS

the relative stability of rotavirus genotypes currently cocirculating in France may ensure vaccine effectiveness in the short and medium term. However, the likely emergence of G12 and G8 strains should be monitored during ongoing and future vaccination programs, especially as all genotypes can cause severe infections. Special attention should be paid to the emergence of new rotavirus reassortants not included in current rotavirus vaccines.

Burden of rotavirus gastroenteritis in the Middle Eastern and North African pediatric population

Background

Rotavirus gastroenteritis (RVGE) is the most common cause of severe childhood diarrhea worldwide. Objectives were to estimate the burden of RVGE among children less than five years old in the Middle East (Bahrain, Iran, Iraq, Israel, Jordan, Kuwait, Oman, Qatar, Saudi Arabia, Syria, UAE, Yemen), North Africa (Algeria, Egypt, Libya, Morocco, Tunisia) and Turkey.

Methods

A comprehensive literature search was conducted in major databases on the epidemiology and burden of rotavirus among children less than five years old between 1999 and 2009. Data from each country was extracted and compared.

Results

The search identified 43 studies. RVGE was identified in 16-61% of all cases of acute gastroenteritis, with a peak in the winter. RVGE-related hospitalization rates ranged from 14% to 45%, compared to 14%-28% for non-RVGE. Annually, RVGE caused up to 112 fatalities per 100,000 in certain countries in the region. Hospitalization costs ranged from $1.8 to $4.6 million annually, depending on the country. The most recent literature available showed that G1P[8] was the most prevalent genotype combination in 8 countries (range 23%-56%). G2P[4] was most prevalent in 4 countries (26%-48%). G9P[8] and G4P[8] were also frequently detected.

Conclusions

RVGE is a common disease associated with significant morbidity, mortality, and economic burden. Given the variety and diverse rotavirus types in the region, use of a vaccine with broad and consistent serotype coverage would be important to help decrease the burden of RVGE in the Middle East and North Africa.

Circulating human group A rotavirus genotypes in Malaysia

This study examined the temporal distribution of rotavirus genotypes in Malaysia. Rotaviruses from children with diarrhea admitted to hospitals in 1996 (n = 93) and 2007 (n = 12) in two different regions of Peninsular (West) Malaysia were analyzed for their G and P genotypes using a hemi-nested RT-PCR assay. In the 2007 samples, the dominant strain was G9P[8]. It was identified in 42% of the samples. Different strains all possessing the G1 genotype were identified in the rest of the samples. In contrast, 81% of the samples collected in 1996 were the G1P[8] strain. No strains with G9 genotype were detected in samples collected in 1996.

Characterization of group A rotavirus infections in adolescents and adults from Pune, India: 1993-1996 and 2004-2007

A total of 1,591 fecal specimens were collected in 1993-1996 and 2004-2007 from adolescents and adults with acute gastroenteritis in Pune, India for detection and characterization of rotavirus. At the two time points, group A rotavirus was detected in 8.6% and 16.2% of the adolescents and 5.2% and 17.2% of the adults, respectively. Reverse transcription-PCR with consensus primers followed by multiplex genotyping PCR detected common strains G1P[8], G2P[4], G3P[8], and G4P[8] in a total of 53.1% of the samples from 1993 to 1996, while the only prevalent strain identified in 2004-2007 was G2P[4] (23.5% of total). Uncommon rotavirus strains (G1P[4], G2P[8] G9P[6]/P[4]) increased from 7.8% (1993-1996) to 41.2% (2004-2007), while the prevalence of mixed rotavirus infections was high (39%/35%) at both time points. Mixed infections detected by multiplex PCR were confirmed by sequencing two or more individual genotype-specific PCR products of the VP7 and VP4 genes from the same sample. Phylogenetic analysis of the sequences showed circulation of a heterogeneous rotavirus strain population comprising genotypes G1 (lineages I and IIb), G2 (lineages I and IIb), G4 (lineage Ia), P[4] (lineages P[4]-5 and P[4]-1), P[8] (lineages P[8]-II and P[8]-III), and P[6] (M37-like lineage). The VP6 gene sequences of the nontypeable strains were most homologous to animal strains. This study documents the molecular epidemiology of rotavirus strains in adolescents and adults in India, and suggests that it may be important to monitor these strains over time for the potential impact on rotavirus vaccines under development for use in the Indian population. J. Med. Virol. 82:519-527, 2010. (c) 2010 Wiley-Liss, Inc.

Modelling the seasonality of rotavirus disease and the impact of vaccination in England and Wales

Two rotavirus vaccines are currently recommended for inclusion in routine childhood immunization programmes. We developed a deterministic age-structured model of rotavirus transmission and disease to investigate the population-level effects of vaccination in England and Wales. The model explicitly captures the natural history of infection and uses realistic population mixing patterns. The model accurately reproduces the strong seasonal pattern and age distribution of rotavirus disease observed in England and Wales. We predict vaccination will provide both direct and indirect protection within the population. If coverage levels comparable to other childhood vaccines are achieved, we predict that vaccination will reduce rotavirus disease incidence by 61% resulting in a potential fall in burden on health-care services.

Rotaviruses

Rotaviruses can be detected easily, and methods have been developed to visualise their characteristic morphology, to detect rotavirus proteins through immunological methods or the virus genome, either directly by polyacrylamide gel electrophoresis or after reverse transcription of the viral RNA and amplification by PCR. The abundance of virus particles found in clinical samples during an acute infection makes the detection of rotavirus proteins, mainly VP6, the method of choice for virus detection. Molecular methods are generally reserved for the characterisation of a diverse population of viruses circulating in many mammalian species. Characterisation methods have been developed to determine diversity within genes encoding viral structural proteins, VP4, VP7, and VP6 and the non-structural protein and viral enterotoxin, NSP4. The combined use of the detection and characterisation methods described in this chapter allows novel rotavirus strains resulting from genetic reassortment among common strains, reassortment among animal and human strains and zoonotic strains to be identified. Also, strains in which diversity is generated through the accumulation of point mutations during virus replication are identified. The development of safe and effective rotavirus vaccines necessitates the detection and characterisation of rotaviruses of genomic and antigenic diversity circulating in both the human and animal populations.

G2P[4] the most prevalent rotavirus genotype in 2007 winter season in an European non-vaccinated population

BACKGROUND

Recently, a high prevalence of G2P[4] rotavirus (RV) infection was reported from Brazil, and linked with the universal RV vaccination programme that used the G1P[8] live oral RV vaccine.

OBJECTIVE

To determine the genotypes of RV co-circulating in a non-vaccinated population, in northern Portugal in the winter season of 2007.

STUDY DESIGN

Prospective multicenter study of the genotypes circulating in the northwest region of Portugal during January to March 2007. Children with acute gastroenteritis, who attended the Pediatric Emergency Services of five Hospitals, were included in the study. The parents of the children completed a clinical and epidemiological data questionnaire and stool samples were collected. Stool samples positive in a RV enzyme immunoassay (EIA) were genotyped by reverse transcriptase-polymerase chain reaction.

RESULTS

Stool samples were collected from 424 children. Two hundred and thirty-four (55.2%) stool samples were RV-positive. G2P[4] was the predominant RV type (68.6%), followed by G9P[8] (14.0%).

CONCLUSIONS

Because our population was naïve for RV vaccine, the G2P[4] predominance cannot be explained by vaccination. Rather, this high prevalence of G2P[4] may be within the normal fluctuation of RV genotypes. RV strain surveillance programmes are important for informing RV vaccination programmes.

Phylogenetic analysis of rotaviruses with predominant G3 and emerging G9 genotypes from adults and children in Wuhan, China

Prevalence and phylogenetic relatedness of rotaviruses causing diarrheal diseases in children and adults were analyzed in Wuhan, China. During a period between June 2006 and February 2008, group A rotavirus was identified in 24.9% (280/1126) and 7.6% (83/1088) of specimens taken from children and adults, respectively. G3P[8] was the most frequent genotype in both children (66.3%) and adults (62.7%), followed by G1P[8] (20.3% and 26.2%, respectively). G9 was detected in specimens from six children (2.0%) and seven adults (5.6%). The VP7 genes of G3P[8] rotaviruses from children and adults showed extremely high sequence identities to each other (98.9-100%) and also to those of G3 viruses isolated in Wuhan in 2003-2004. In the phylogenetic analysis of the VP7 gene, the G3P[8] rotaviruses in Wuhan were clustered into a single lineage with some G3 viruses, which had been referred to as "the new variant G3" rotaviruses, reported recently in East Asia and Southeast Asia. Similar to G3P[8] rotaviruses, extremely high sequence identities between children and adults were observed for VP7 genes of G1 and G9 rotaviruses. The G9 viruses were clustered in the lineage of globally spreading strains, while G1 viruses were genetically close to those reported previously in China and Japan. These findings indicated the persistence of the variant G3 rotaviruses and spread of G9 rotaviruses derived from the global G9 lineage in Wuhan, and suggested that the rotaviruses were circulating among children and adults, irrelevant to the G types.

Outbreak of rotavirus variant P[8] in Seoul, South Korea

An epidemiologic study was performed to determine the genetic variability of rotaviruses in Seoul, South Korea. In 3,174 stool specimens from children with acute diarrhea at five referral hospitals, 571 (18%) possessed the antigen of group A rotavirus detectable by ELISA--10.8% in 2004 and 28.1% in 2005. VP7 genotyping revealed that the G3 type was found in 25.6% of all typed isolates, G4 in 23.8%, G2 in 21.6%, and G1 in 17.6%. VP4 genotyping showed that the P[8] type was detected in 66.7%, P[6] in 15.6%, P[4] in 13.0%, and P[9] in 0.2%. Because the variant P[8] type could not be amplified initially by conventional P typing primers (1T-1), PCR were performed using newly designed 1T-1S primer, which revealed that 307 specimens were the variant P[8] type. Uncommon combinations such as G4P[6] and G2P[8] were also found with relatively high prevalence, 14.6% and 12.8%, respectively. Variant P[8] types were associated with an outbreak of rotavirus in 2005.

Molecular epidemic features and variation of rotavirus among children with diarrhea in Lanzhou, China, 2001-2006

BACKGROUND

Human rotavirus (HRV) is the most common pathogen causing severe diarrhea among infants and young children worldwide. This study aims to understand rotavirus epidemiology and its variation in the period of 2001-2006 in Lanzhou, Gansu Province, China, and to provide an epidemiological basis for the development of rotavirus vaccine.

METHODS

A total of 1019 stool specimens were collected from patients with acute diarrhea admitted to the First Hospital of Lanzhou University from 2001 to 2006, who were younger than 5 years old. Dako IDEIATM kits were used for detection of rotavirus, and RT-PCR was performed for determination of G serotype and P genotype of the rotavirus.

RESULTS

Rotavirus was present in 51.6% (526) of the 1019 specimens. G serotype identified G3 at 40.9%, G2 14.6%, G1 22.2% and G9 1.9%. Mixed-G infection was observed in 4.4% and non-typeable infection 16.0%. P genotype was observed in 372 samples, of which P[8] accounted for 186 cases (50.0%), P[4] 72 cases (19.4%), mixed-P infection 2 cases (0.5%), and non-typeable cases 112 (30.1%). G3 was the most prevalent G serotype found in this study from 2001 to 2004, G2 was the most prevalent G serotype (34.4%) from 2004 to 2005, and G1 (61.5%) was the most prevalent strain from 2005 to 2006. G9 was detected in 10 cases (1.9%) and G4 was not detected during this 5-year period. P[8] was the most prevalent P genotype found over the 5 consecutive years of this study, although there was a significant transition of P genotype from 2004 to 2005 with P[4] (45%) identified as the predominant P genotype, followed by P[8] (22.1%). The predominant G-P combination was P[8]G1 (33.6%), followed by P[8]G3 (32.1%) and P[4]G2 (17.2%). Rotavirus diarrhea admissions peaked between October and December. Continuous surveillance showed that the incidence rate of rotavirus was the highest in infants aged 6-23 months, averaging 11.0-11.9 months.

CONCLUSIONS

Five years of continuous surveillance showed that rotavirus remains the most significant viral agent causing diarrhea hospitalization among children under 5 years old in Lanzhou, China although the predominant strain of rotavirus varies between years. Mixed-G serotype infection also appears to occur at a relatively high rate in Lanzhou.

Prospective study of the burden of acute gastroenteritis and rotavirus gastroenteritis in children less than 5 years of age, in Padova, Italy

BACKGROUND

Data on the burden of rotavirus gastroenteritis in Europe are needed to help understand the potential impact of introducing new rotavirus vaccines.

MATERIALS AND METHODS

As part of prospective observational study (Rotavirus gastroenteritis Epidemiology and Viral types in Europe Accounting for Losses in Public Health and Society Study, REVEAL) conducted in 2004--2005 in seven European countries, we studied, the characteristics of acute gastroenteritis and rotavirus gastroenteritis in children less than 5 years in primary care, emergency room and hospital settings (Padova, Italy).

RESULTS

A total of 757 children with acute gastroenteritis were included and enzyme-linked immunoabsorbent assay (ELISA) results were available for 725 cases. The overall estimated annual incidence for rotavirus gastroenteritis was 4.7%. Overall, rotavirus gastroenteritis was estimated to account for 43.6% of acute gastroenteritis cases. Among children with acute gastroenteritis (AGE) aged 6-23 months, 61.2% were rotavirus positive. Rotavirus gastroenteritis (RVGE) was responsible for 68.8% of hospitalizations, 61% of emergency consultations, and 33% of primary care consultations. The most prevalent serotype was G9 (84.4%) followed by G1 (11.8%). The relative risk for rotavirus gastroenteritis of being referred to hospital after an initial consultation in primary care was 3.37 (95% CI: 1.77-6.43) and 3.38 (95% CI: 2.28-5.01) for emergency room referral. Children with rotavirus gastroenteritis generally had more severe disease than children with rotavirus-negative gastroenteritis.

CONCLUSION

Rotavirus accounts for a significant proportion of acute gastroenteritis cases in children less than 5 years in Italy, many of whom require frequent primary care consultations, or care in emergency room or hospital settings.

New oligonucleotide primers for P-typing of rotavirus strains: Strategies for typing previously untypeable strains

BACKGROUND

The use of molecular methods for rotavirus characterisation provides increased sensitivity for typing, and allows the identification of putative reassortant strains. However, due to the constant accumulation of point mutations through genetic drift; and to the emergence of novel genotypes; and possibly zoonotic transmission and subsequent reassortment, the reagents and methods used for genotyping require close monitoring and updating.

OBJECTIVES

To design and evaluate a new VP4 consensus oligonucleotide primer pair that provides increased sensitivity and allows typing of strains that were untypeable using available methods.

STUDY DESIGN

A total of 489 rotavirus-positive faecal specimens from studies conducted between 1996 and 2006 were used for the evaluation of the new VP4 primers which was performed in the WHO Rotavirus Collaborating and Reference centres in the US, Australia, South Africa and the UK.

RESULTS

The new primer pair allowed P-typing of rotavirus strains and provided increased sensitivity, allowing typing of a significant number of strains that previously could not be P-typed.

CONCLUSIONS

This study highlights the importance of a constant reconsideration of primer sequences employed for the molecular typing of rotaviruses.