Emergence of serotype G12 rotaviruses, Hungary

Detection and characterization of rotavirus G and P types from children with acute gastroenteritis in Qom, central Iran

AIM

The aim of the study is to estimate the burden of Rotavirus gastroenteritis as well as predominant genotypes of Rotavirus among children less than 5 years of age referring to Pediatric University Hospital in Qom, Iran.

BACKGROUND

Gastroenteritis is the fourth most common cause of death and accounts for 16% of all deaths in children <5 years of age worldwide.

METHODS

During two years, 130 patients referring to a pediatric hospital were enrolled in this study. After RNA extraction, Rotaviruses were detected by the VP6 gene. Then, G-typing (G1, G2, G3, G4, G8, G9, and G12) and P-typing (P4, P6, and P8) were performed using RT-PCR and specific primers.

RESULTS

The results of the PCR revealed that from a total of 130 patients, 22 cases (16.9%) showed positive VP6 by RT-PCR. G1 was mostly the predominant serotype (27%), accounting for 22% of all VP7-positive isolates, followed by G9 (18%), G2 (9%), G3 (9%), and G4 (9%). None of the strains revealed the presence of G8 genotype (0%), and 5 specimens (23%) were non-typable. The frequency of P typing was P8 (50%), P6 (23%), P4 (14%), and 3 samples were P-non-typable (13%), respectively. The dominant G-P combination was G1 [8] (32%).

CONCLUSION

Such studies based on typing methods assists in the Rotavirus vaccine introduction by policymakers and design of new effective vaccines.

Distribution of Rotavirus Genotypes Ccirculating in Ahvaz, Iran in 2016

Background

Group A rotavirus (RVA) mainly causes acute gastroenteritis, exclusively in young children in developing countries. The prevalence and determination of the molecular epidemiology of rotavirus genotypes will determine the dominant rotavirus genotypes in the region and provide a strategy for the development of appropriate vaccines.

Methods

A total of 100 fecal samples were collected from children below five years with acute gastroenteritis who referred to Aboozar Children’s Hospital of Ahvaz city during October 2015 to March 2016. All samples were screened by latex agglutination for the presence of rotavirus antigen. Rotavirus-positive samples were further analyzed by the semi-multiplex RT-PCR, and the sequencing was performed for G/P genotyping.

Results

Findings showed that 32% of the specimens were RVA-positive. Among the 32 VP7 genotyped strains, the predominant G genotype was G9 (37.5%), followed by G2 (21.9%), G1 (12.5%), G12 (9.4%), G4 (9.4%), G2G9 (6.3%), and G3 (3.1%). Among the 31 VP4 genotyped strains, P[8] genotype was the dominant (62.5%), followed by P[4] (31.3%) and P[4] P[8] (3.1%). The genotypes for G and P were identified for 31 rotaviruses (96.87%), but only one strain, G9, remained non-typeable for the P genotype. The most prevalent G/P combination was G9P[8] (28.5%), followed by G2P[4] (18.8%), G1P[8] (9.4%), G12P[8] (9.4%), G4P[8] (9.4%), G2G9P[4] (6.3%), G9P[4] P[8] (3.1%), G3P[8] (3.1%), G9P[4] (3.1%), G2P[8] (3.1%), and G9P[non-typeable] (3.1%).

Conclusion

A novel rotavirus strain, G12, was detected, for the first time, in patients from the southwest of Iran. Comprehensive investigations are required to evaluate the emergence of this strain.

Molecular characterization of rotavirus disclosed the first introduction of G12P[8] strain in northern Italy

Aim: This paper discusses the unexpected findings from the RotaNet-Italy hospital-based surveillance study carried out in northern Italy. Materials & methods: From September 2015 to August 2016, 51 rotavirus-A (RVA) positive fecal samples were collected from children aged less than 15 years, who were hospitalized for acute gastroenteritis in Lombardy, northern Italy. Results: Molecular characterization revealed the predominance of the uncommon G12P[8] RVA strain, which was detected in 49% of cases. Phylogenetic analysis showed that these G12 strains clustered into lineage 3. Conclusion: To our knowledge, this is the first study on the G12P[8] genotype’s introduction in northern Italy. Our findings emphasize the importance of the surveillance of RVA gastroenteritis with the aim of obtaining new insight into the unusual newly emerging RVA strains.

Molecular epidemiology of Rotavirus causing diarrhea among children less than five years of age visiting national level children hospitals, Nepal

Background

Rotaviruses are the major cause of diarrhea among the infants and young children all over the world causing over 500,000 deaths and 2.4 million hospitalizations each year. In Nepal Rotavirus infection positivity rates ranges from 17.0 to 39.0% among children less than 5 years. However, little is known about the molecular genotypes of Rotavirus prevailing. The objective of this study was to estimate the burden of Rotavirus gastroenteritis and determine the genotypes of Rotavirus among children less than 5 years.

Methods

The cross sectional study was conducted from January to November 2014 among children less than 5 years old visiting Kanti Children’s Hospital and Tribhuvan University Teaching Hospital.

Rotavirus antigen detection was performed by Enzyme Linked Immunosorbent Assay (ELISA) using ProSpecT Rotavirus Microplate Assay. Among the Rotavirus antigen positive samples, 59 samples were used for Rotavirus RNA extraction. Multiplex PCR was performed to identify G type comprising G1-G4, G8-G10 and G12 and P type comprising P[4], P[6], P[8], P[9], P[10], and P[11].

Results

A total of 717 diarrheal stool samples were collected from patients ranging from 10 days to 59 months of age. Rotavirus antigen positive was found among (N = 164)22.9% of patients. The highest number of the diarrhea was seen in January. Molecular analysis of Rotavirus genotypes revealed that the predominant G-Type was G12 (36%) followed by G9 (31%), G1 (21%), G2 (8.6%). The predominant P- type was P6 (32.8%) followed by P8 (31%), P10 (14.8%), P4 (14.8%). A total of seven G/P type combinations were identified the most common being G12P [6] (35.8%), G1P [8] (15.1%), G9P [8] (15.1%).

Conclusion

Rotavirus diarrhea is, mostly affecting children from 7 to 24 months in Nepal, mostly occurring in winter. The circulating genotypes in the country are found to be primarily unusual genotypes and predominance of G12P[6]. It is recommended to conduct genotyping of Rotavirus on large samples before starting vaccination in the country.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-017-0858-0) contains supplementary material, which is available to authorized users.

VP7 and VP8* genetic characterization of group A rotavirus genotype G12P[8]: Emergence and spreading in the Eastern Brazilian coast in 2014

Group A rotavirus (RVA) genotype G12 is habitually associated with diarrhea disease (DD) in African children and recently its detection has increased worldwide. A total of 970 stool samples collected from individuals with DD in the Northeastern, Southeastern, and Southern Brazilian regions, Eastern coast, were analyzed and 321 (33%) were positive for RVA and of these, 241 (75%) genotyped as G12P[8]. The rate of RVA positivity was higher among children aged 5-10 years old (60%). All RVA infections observed in adults aged >21 years were G12P[8] (n = 27) showing that this genotype affected older age groups during the year of 2014 in Brazil. Phylogenetic analysis of VP7 and VP8* G12P[8] strains demonstrated an elevated similarity among Brazilian and G12-III prototypes strains circulating worldwide recently, suggesting that this lineage is associated with the global spread of the G12 genotype, considered as the 6th most prevalent human RVA genotype nowadays; while other G12 lineages remain sporadically detected and usually detected in association with other P genotypes. VP8* analysis revealed that Brazilian strains belong to P[8]-3 lineage, the single P[8] lineage presently detected in the country. No major nucleotide/amino acid disparities were observed among strains recovered from children and adults for VP7 and VP8* genes. These data are essential to support the surveillance studies, particularly in countries where the RVA vaccine was introduced in their National Immunization Program enabling identification of potential alterations in the epidemiological profile that can impact its efficacy in vaccination programs. J. Med. Virol. 89:64-70, 2017. © 2016 Wiley Periodicals, Inc.

Distribution of rotavirus VP7 and VP4 genotypes circulating in Tunisia from 2009 to 2014: Emergence of the genotype G12

Group A rotavirus (RVA) represents the most important aetiological agent of diarrhoea in children worldwide. From January 2009 to December 2014, a multi-centre study realized through 11 Tunisian cities was undertaken among children aged <5 years consulting or hospitalized for acute gastroenteritis. A total of 1127 faecal samples were collected. All samples were screened by ELISA for the presence of RVA antigen. RVA-positive samples were further analyzed by PAGE and used for G/P-genotyping by semi-nested multiplex RT-PCR. Globally, 270 specimens (24 %) were RVA-positive, with peaks observed annually between November and March. Nine different electropherotypes could be visualized by PAGE, six with a long profile (173 cases) and two with a short one (seven cases). Mixed profiles were detected in two cases. Among the 267 VP7 genotyped strains, the predominant G- genotype was G1 (39.6 %) followed by G3 (22.2 %), G4 (13 %), G9 (11.5 %), G2 (5.2 %) and G12 (5.2 %). Among the 260 VP4 genotyped strains, P[8] genotype was the predominant (74.5 %) followed by P[6] (10.4 %) and P[4] (5.5 %). A total of 257 strains (95.2 %) could be successfully G- and P-genotyped. G1P[8] was the most prevalent combination (34.4 %), followed by G3P[8] (16.3 %), G9P[8] (10.3 %), G4P[8] (8.9 %), G2P[4] (4 %), G12P[6] (2.6 %) and G12P[8] (1.9 %). Uncommon G/Pgenotype combinations, mixed infections and untypeable strains were also detected. This is the first report, in Tunisia, of multiple detection of an emerging human RVA strain, G12 genotype. This study highlighted the need for maintaining active surveillance of emerging strains in Northern Africa.

Detection of the emerging rotavirus G12P[8] genotype at high frequency in brazil in 2014: Successive replacement of predominant strains after vaccine introduction

The continuum characterization of rotavirus (RVA) genotypes is essential to understand how vaccine introduction could impact virus epidemiology. In the present study, an unexpected rapid changing pattern of RVA genotypes distribution in Brazilian population during three followed seasons is described. From January/2012 to December/2014, a total of 3441 fecal specimens were collected from collaborating centers across Southern, Southeastern and Midwest of Brazil. All specimens were screened for RVA using ELISA, and genotyped by RT-PCR. Differences in proportions were tested using Chi-Squares. A p-value of less than 0.05 was considered statistically significant. RVA was detected in 19.7% (677/3441). Among RVA positive cases (n=677), a total of 652 (96.3%) samples were successfully amplified by RT-PCR. G3P[8] remained prevalent in 2012 (37.6%, 69/185) and 2013 (40.1%, 74/186) (χ(2)=0.107, p=0.743), but declined markedly in 2014 (3.5%, 10/281) (χ(2)=71.770, p=0.000). G12P[8] was second highest strain in 2012 (22.7%, 42/185), decrease rapidly in 2013 (2.7%, 5/186) (χ(2)=26.224, p=0.000) and re-emerged as the predominant genotype in 2014 (86.6%, 243/281) (χ(2)=118.299, p=0.000). From July/2014, G12P[8] was the single genotype detected in all regions studied. The sudden emergence, spread and predominance of G12P[8] strain in Brazil, raised the hypothesis of a possible G12 outbreak being in progress. Nationally, the long term decline in gastroenteritis hospitalization observed in the country after RVA vaccine introduction was confirmed. Nevertheless, the sharp increase in diarrhea hospitalization prevalence from 2013 to 2014 observed in Southern and Southeastern regions is consistent with what appears to be an outbreak of G12P[8]. Continued surveillance is needed to verify the effectiveness of the RotarixTM vaccine in Brazil together with potential emergence of unusual genotypes.

Epidemiology of rotavirus A diarrhea in Chókwè, Southern Mozambique, from February to September, 2011

Acute diarrhea disease caused by Rotaviruses A (RVA) is still the leading cause of morbidity and mortality in children ≤5 years old in developing countries. An exploratory cross-sectional study was conducted between February and September, 2011 to determine the proportion of acute diarrhea caused by RVA. A total of 254 stool specimens were collected from children ≤5 years old with acute diarrhea, including outpatients (222 children) and inpatients (32 children), in three local health centers in Chókwè District, Gaza Province, South of Mozambique. RVA antigens were detected using enzyme immunoassay (EIA); the RVA G (VP7) and P (VP4) genotypes were determined by RT-PCR or analysis sequencing. Sixty (24%) out of 254 fecal specimens were positive for RVA by EIA; being 58 (97%) from children ≤2 years of age. RVA prevalence peaks in June and July (coldest and drier months) and the G[P] binary combination observed were G12P[8] (57%); G1P[8] (9%); G12P[6] (6%); and 2% for each of the following genotypes: G1P[6], G2P[6] G4P[6], and G9P[8]. Non-Typeable (NT) G and/or P genotypes were observed as follows: G12P [NT] (6%); G1P [NT], G3P[NT] and GNTP[NT] (4%). Considering the different GP combinations, G12 represented 67% of the genotypes. This is the first data showing the diversity of RVA genotypes in Mozambique highlighting the epidemiological importance of these viruses in acute diarrhea cases in children ≤2 years old. In addition, these findings will provide a baseline data before the introduction of the RVA monovalent (Rotarix(®) ) vaccine in the National Immunization Program in September 2015. J. Med. Virol. 88:1751-1758, 2016. © 2016 Wiley Periodicals, Inc.

Introduction and prolonged circulation of G12 rotaviruses in Sicily

Genotype G12 strains are now considered to be the sixth most prevalent human rotaviruses worldwide. In two Sicilian cities, Palermo and Messina, surveillance of rotavirus circulation performed since 1985 and 2009, respectively, did not detect G12 strains until 2012. From 2012 to 2014 rotavirus infection was detected in 29·7% of 1647 stool samples collected from children admitted for acute gastroenteritis to three Sicilian hospitals in Palermo, Messina and Ragusa. In 2012, G12P[8] was first detected in Palermo and then in Messina where it represented the second most frequent genotype (20% prevalence) after G1P[8]. Thereafter, G12 strains continued to circulate in Sicily, showing a marked prevalence in Ragusa (27·8%) in 2013 and in Palermo (21%) and Messina (16·6%) in 2014. All but one of the Sicilian G12 strains carried a P[8] VP4 genotype, whereas the single non-P[8] rotavirus strain was genotyped as G12P[9]. Phylogenetic analysis of the VP7 and VP4 sequences allowed distinction of several genetic lineages and separation of the G12P[8] strains into three cluster combinations. These findings indicate independent introductions of G12 rotavirus strains in Sicily in recent years.

First report of gastroenteritis by genotype G12 rotavirus in Dakar, Senegal

The genotype G12 rotavirus was isolated from the stool of children 5 years old or younger with acute gastroenteritis during 1 year in three Dakar hospitals. The G12 genotype was the most common (58.25%). VP4 genotyping revealed mixed genotypes (1.94%).

Large-scale whole genome sequencing identifies country-wide spread of an emerging G9P[8] rotavirus strain in Hungary, 2012

With the availability of rotavirus vaccines routine strain surveillance has been launched or continued in many countries worldwide. In this study relevant information is provided from Hungary in order to extend knowledge about circulating rotavirus strains. Direct sequencing of the RT-PCR products obtained by VP7 and VP4 genes specific primer sets was utilized as routine laboratory method. In addition we explored the advantage of random primed RT-PCR and semiconductor sequencing of the whole genome of selected strains. During the study year, 2012, we identified an increase in the prevalence of G9P[8] strains across the country. This genotype combination predominated in seven out of nine study sites (detection rates, 45-83%). In addition to G9P[8]s, epidemiologically major strains included genotypes G1P[8] (34.2%), G2P[4] (13.5%), and G4P[8] (7.4%), whereas unusual and rare strains were G3P[8] (1%), G2P[8] (0.5%), G1P[4] (0.2%), G3P[4] (0.2%), and G3P[9] (0.2%). Whole genome analysis of 125 Hungarian human rotaviruses identified nine major genotype constellations and uncovered both intra- and intergenogroup reassortment events in circulating strains. Intergenogroup reassortment resulted in several unusual genotype constellations, including mono-reassortant G1P[8] and G9P[8] strains whose genotype 1 (Wa-like) backbone gene constellations contained DS1-like NSP2 and VP3 genes, respectively, as well as, a putative bovine-feline G3P[9] reassortant strain. The conserved genomic constellations of epidemiologically major genotypes suggested the clonal spread of the re-emerging G9P[8] genotype and several co-circulating strains (e.g., G1P[8] and G2P[4]) in many study sites during 2012. Of interest, medically important G2P[4] strains carried bovine-like VP1 and VP6 genes in their genotype constellation. No evidence for vaccine associated selection, or, interaction between wild-type and vaccine strains was obtained. In conclusion, this study reports the reemergence of G9P[8] strains across the country and indicates the robustness of whole genome sequencing in routine rotavirus strain surveillance.

Update of rotavirus strains circulating in Africa from 2007 through 2011

BACKGROUND

The African Rotavirus Surveillance Network has been detecting and documenting rotavirus genotypes in the subcontinent since 1998, largely based on intercountry workshops conducted at Rotavirus Regional Reference Laboratories. This article reports on rotavirus genotypes generated at Regional Reference Laboratories, South Africa between 2007 and 2011 from 16 African countries.

METHODS

Stool samples were collected from <5-year-old children with diarrhea following World Health Organization criteria of hospital-based rotavirus surveillance. Enzyme immunoassay (EIA) was performed by National Laboratories. Regional Reference Laboratories retested 10% of randomly selected EIA positives and 10% of EIA negatives from each country as part of quality control. At least 50 rotavirus EIA positives from each country per year were subjected to reverse transcriptase polymerase chain reaction based on G-/P-types. Sequencing was conducted in 5-10% of each representative G or P genotype to confirm the genotype, as well as to type some of the samples that could not be genotyped with reverse transcriptase polymerase chain reaction-based methods.

RESULTS

A total of 2555 of rotavirus EIA positives were genotyped. G1 was the most predominant (28.8%), followed by G9 (17.3%), G2 (16.8%), G8 (8.2%), G12 (6.2%) and G3 (5.9%). Similarly, the P[8] strain was the most prevalent (40.6%), followed by P[6] (30.9%) and P[4] (13.9%). The top G/P combinations detected were G1P[8] (18.4%), G9P[8] (11.7%), G2P[4] (8.6%), G2P[6] (6.2%), G1P[6] (4.9%), G3P[6] (4.3%), G8P[6] (3.8%) and G12P[8] (3.1%).

CONCLUSIONS

There is high genetic diversity of rotavirus strains circulating in the subcontinent. Understanding the strain diversity pre- and postvaccine introduction are important in Africa to understand the broader impact of the rotavirus vaccines on regionally circulating strains.

One year survey of human rotavirus strains suggests the emergence of genotype G12 in Cameroon

In this study the emergence of rotavirus A genotype G12 in children <5 years of age is reported from Cameroon during 2010/2011. A total of 135 human stool samples were P and G genotyped by reverse transcriptase PCR. Six different rotavirus VP7 genotypes were detected, including G1, G2, G3, G8, G9, and G12 in combinations with P[4], P[6] and P[8] VP4 genotypes. Genotype G12 predominated in combination with P[8] (54.1%) and P[6] (10.4%) genotypes followed by G1P[6] (8.2%), G3P[6] (6.7%), G2P[4] (5.9%), G8P[6] (3.7%), G2P[6] (0.7%), G3P[8] (0.7%), and G9P[8] (0.7%). Genotype P[6] strains in combination with various G-types represented a substantial proportion (N=44, 32.6%) of the genotyped strains. Partially typed strains included G12P[NT] (2.2%); G3P[NT] (0.7%); G(NT)P[6] (1.5%); and G(NT)P[8] (0.7%). Mixed infections were found in five specimens (3.7%) in several combinations including G1+ G12P[6], G2+ G3P[6] + P[8], G3+ G8P[6], G3 + G12P[6] + P[8], and G12P[6] +P[8]. The approximately 10% relative frequency of G12P[6] strains detected in this study suggests that this strain is emerging in Cameroon and should be monitored carefully as rotavirus vaccine is implemented in this country, as it shares neither G- nor P-type specificity with strains in the RotaTeq® and Rotarix® vaccines. These findings are consistent with other recent reports of the global spread and increasing epidemiologic importance of G12 and P[6] strains.

Genetic analysis of G12P[8] rotaviruses detected in the largest U.S. G12 genotype outbreak on record

In 2006-07, 77 cases of gastroenteritis in Rochester, NY, USA were associated with rotavirus genotype G12P[8]. Sequence analysis identified a high degree of genetic relatedness among the VP7 and VP4 genes of the Rochester G12P[8] strains and between these strains and currently circulating human G12P[8] strains. Out of 77 samples, two and seven unique nucleotide sequences were identified for VP7 and VP4 genes, respectively. Rochester strain VP7 genes were found to occupy the G12-III lineage and VP4 genes clustered within the P[8]-3 lineage. Six strains contained non-synonymous nucleotide substitutions that produced amino acid changes at 6 sites in the VP8(∗) region of the VP4 gene. Two sites (amino acids 242 and 246) were located in or near a described trypsin cleavage site. Selection analyses identified one positively selected VP7 site (107) and strong purifying selection at 58 sites within the VP7 gene as well as 2 of the 6 variant sites (79 and 218) in VP4.

Shared G12 VP7 gene among human and bovine rotaviruses detected in Cameroonian villages

Group A rotaviruses (RVA) are an important enteric pathogen in humans and livestock animals. Transmission of animal RVA strains to humans has been documented on several occasions. A reverse route of transmission of RVA under natural circumstances is anticipated, although evidence is scarce. However, experimental studies indicated that animals can be infected with human RVAs. By screening the stool samples collected from 157 cattle during 2011 in two Cameroonian villages, four samples (2.5%) were found positive for RVA. Upon sequence analysis of a 410 bp fragment of the VP7 gene, the RVA strains shared up to 100% nt identity to each other and to G12 RVAs identified in human patients living in the same geographic regions. This finding provides evidence for a human-to-animal transmission of an epidemic human rotavirus strain.

Molecular epidemiology of rotavirus and norovirus in Ile-Ife, Nigeria: high prevalence of G12P[8] rotavirus strains and detection of a rare norovirus genotype

Rotavirus (RV) and norovirus (NoV) are considered the most common causes of viral gastroenteritis in children. In this study, the prevalence of RV and NoV infection in 55 children with diarrhea from the rural community Akinlalu in Southwestern Nigeria was investigated using real-time PCR assays. The RV and NoV strains were genotyped by PCR and/or sequencing. RV and NoV infections occurred with a prevalence of 34.5% and 25.5% respectively, with predominance in children <1 year. Most infections occurred during the dry season with increasing prevalence of RV as the dry season progressed (October-January). Infections with RV VP6 subgroup (SG) II were more prevalent (27.3%) than SGI (7.3%). Similarly, NoV genogroup II infections were more common (23.6%) than genogroup I (1.8%). Five children out of 55 (9.1%) were co-infected with both RV and NoV. Notably, G12P[8] was the predominant RV strain (36.8%, n = 7), observed for the first time in Nigeria. The VP7 gene of the G12 strains clustered within lineage III, sharing high nucleotide identity with each other (>99%) indicating introduction in Nigeria from a single donor. Furthermore, a putative novel genotype within genogroup I NoV was detected, which till date has only been reported once in humans. To conclude, a high prevalence of the emerging G12P[8] RV strain was observed for the first time in Nigeria, as well as a putative novel NoV genotype in humans. These results provide new information which can be important for future vaccine evaluations and possible introduction in Nigeria.

Surveillance of human rotaviruses in 2007-2011, Hungary: exploring the genetic relatedness between vaccine and field strains

BACKGROUND

The availability of rotavirus vaccines has resulted in an intensification of post vaccine strain surveillance efforts worldwide to gain information on the impact of vaccines on prevalence of circulating rotavirus strains.

OBJECTIVES

In this study, the distribution of human rotavirus G and P types in Hungary is reported. In addition, the VP4 and VP7 genes of G1P[8] strains were sequenced to monitor if vaccine-derived strains were introduced and/or some strains/lineages were selected against.

STUDY DESIGN

The study was conducted in 8 geographic areas of Hungary between 2007 and 2011. Rotavirus positive stool samples were collected from diarrheic patients mostly <5 years of age. Viral RNA was amplified by multiplex genotyping RT-PCR assay, targeting the medically most important G and P types. When needed, sequencing of the VP7 and VP4 genes was performed.

RESULTS

In total, 2380 strains were genotyped. During the 5-year surveillance we observed the dominating prevalence of genotype G1P[8] (44.87%) strains, followed by G4P[8] (23.4%), G2P[4] (14.75%) and G9P[8] (6.81%) genotypes. Uncommon strains were identified in a low percentage of samples (4.12%). Phylogenetic analysis of 318 G1P[8] strains identified 55 strains similar to the Rotarix strain (nt sequence identities; VP7, up to 97.9%; VP4, up to 98.5%) although their vaccine origin was unlikely.

CONCLUSIONS

Current vaccines would have protected against the majority of identified rotavirus genotypes. A better understanding of the potential long-term effect of vaccine use on epidemiology and evolutionary dynamics of co-circulating wild type strains requires continuous strain surveillance.

Rotavirus genotypes in children in the Basque Country (North of Spain): rapid and intense emergence of the G12[P8] genotype

Between July 2009 and June 2011, rotavirus was detected in 507 of 4597 episodes of acute gastroenteritis in children aged <3 years in Gipuzkoa (Basque Country, Spain), of which the G-type was determined in 458 (90·3%). During the annual seasonal epidemic of 2010-2011, the unusual G-type 12 was predominant, causing 65% (145/223) of cases of rotavirus gastroenteritis. All the G12 strains were clustered in lineage III and were preferentially associated with P-type 8. This epidemic was characterized by broad geographical distribution (rural and urban) and, over 7 months, affected both infants and children, the most frequently affected being children between 4 and 24 months. Of children with rotavirus G12, 16% required hospital admission, the admission rate in children aged <2 years being 20·7 cases/10 000 children. The sudden emergence and predominance of G12 rotaviruses documented in this winter outbreak suggest that they may soon become a major human rotavirus genotype.

Human infection with novel G3P[25] rotavirus strain in Taiwan

Genotype P[25] rotaviruses are rare and to date have been reported to occur only in a few countries of mainland Asia. Here we report the molecular characterization of a novel human rotavirus genotype combination, G3P[25], detected in a 17-month-old child hospitalized due to severe gastroenteritis during 2009 in central Taiwan. Sequencing and phylogenetic analysis of the VP4 gene demonstrated a distinct origin from other strains bearing the P[25] VP4 gene, whereas the VP7, VP6 and NSP4 gene phylogenies identified common origins with cognate genes of other, presumed human-porcine reassortment Taiwanese strains. These results suggest that interactions between human and animal strains appear to contribute to the generation of genetic and antigenic diversity of rotavirus strains, with potential public health importance in Taiwan.

Rotavirus infection: a perspective on epidemiology, genomic diversity and vaccine strategies

For centuries, acute diarrhea has been a major cause of death in young children worldwide, and until 1973, before rotavirus was discovered; no infectious agents could be identified in about 80% of patients admitted to hospital with severe dehydrating diarrhea. Rotaviruses have now been shown to cause 40-50% of severe acute diarrhea in young children worldwide in both developing and developed countries. More than 600,000 young children die and approximately 2.4 million hospitalize annually from rotavirus disease, especially in South-East Asia and sub-Saharan Africa. Two safe and effective vaccines are now licensed in 100 countries but used in 17 countries. Rotarix (GSK) vaccine is derived from single attenuated human rotavirus G1P[8], representative of the most common serotype identified worldwide. RotaTeq (Merck) is a pentavalent mixture of naturally attenuated bovine/human rotavirus reassortants representing G1, G2, G3, G4, and P[8] serotypes. Though these vaccines have already dramatically decreased the morbidity associated with rotavirus in countries where they are widely used, the third generation of vaccines, based on inactivated viruses or recombinant virus like particle are already in pipeline. Continuous surveillance and the genetic and antigenic analysis of the various strains of rotavirus circulating worldwide will aid significantly in assessing the effectiveness of these vaccines and monitor emergence of new strains. Introduction of rotavirus vaccines in national vaccine policy along with other childhood vaccines may result in significant reduction in mortality in children in poor socioeconomic countries.

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.

Molecular characterization of group A rotaviruses detected in children with gastroenteritis in Ireland in 2006–2009

Community and hospital-acquired cases of human rotavirus are responsible for millions of gastroenteritis cases in children worldwide, chiefly in developing countries, and vaccines are now available. During surveillance activity for human rotavirus infections in Ireland, between 2006 and 2009, a total of 420 rotavirus strains were collected and analysed. Upon either PCR genotyping and sequence analysis, a variety of VP7 (G1–G4 and G9) and VP4 (P[4], P[6], P[8] and P[9]) genotypes were detected. Strains G1P[8] were found to be predominant throughout the period 2006–2008, with slight fluctuations seen in the very limited samples available in 2008–2009. Upon either PCR genotyping and sequence analysis of selected strains, the G1, G3 and G9 viruses were found to contain E1 (Wa-like) NSP4 and I1 VP6 genotypes, while the analysed G2 strains possessed E2 NSP4 and I2 VP6 genotypes, a genetic make-up which is highly conserved in the major human rotavirus genogroups Wa- and Kun-like, respectively. Upon sequence analysis of the most common VP4 genotype, P[8], at least two distinct lineages were identified, both unrelated to P[8] Irish rotaviruses circulating in previous years, and more closely related to recent European humans rotaviruses. Moreover, sequence analysis of the VP7 of G1 rotaviruses revealed the onset of a G1 variant, previously unseen in the Irish population.

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.

Molecular characterization of rare G12P[6] rotavirus isolates closely related to G12 strains from the United States, CAU 195 and CAU 214

Two human G12 rotaviruses, CAU 195 and CAU 214, were isolated from South Korea using cell culture and characterized on the basis of sequence divergence in the VP7, VP4, and NSP4 genes. Phylogenetic analysis of the VP7 gene sequences indicated that these strains clustered into lineage III and were most closely related to G12 rotaviruses isolated in the United States. The VP4 and NSP4 gene sequences showed that two strains belonged to the P[6]-Ia lineage and genotype [B]. This finding provides information that can be used to evaluate G12 strains and aid in the development of effective vaccines in the future.

Nosocomial rotavirus gastroenteritis in Spain: a multicenter prospective study

BACKGROUND

The objective of this study was to assess the incidence of nosocomial rotavirus gastroenteritis among children <2 years of age.

METHODS

We conducted a prospective active surveillance for acute gastroenteritis (AGE) in the pediatric wards of 3 representative hospitals in Valencia (Spain) from October 2006 to March 2007, among children between 1 and 23 months of age with acute diarrhea. Children were followed up for 3 days after discharge. We obtained clinical and demographic information from participants and tested their stool specimens for rotavirus.

RESULTS

A total of 1576 children were hospitalized at the 3 hospitals and 1300 (82.5%) were followed up as the study cohort. In 69 children, AGE started 48 hours after admission and were considered nosocomial infections. In 35 of the 59 cases where stool samples were obtained, rotavirus (RV) was present (59%), and in 12 of them symptoms started after discharge. The accumulated incidence of nosocomial rotavirus disease during the study period was 2.8 cases per 100 inpatients (95% CI: 1.9-3.8), and the incidence rate was 4.8 cases per 1000 hospital days (95% CI: 3.2-6.5). The most commonly found genotype in nosocomial infection was G9P[8], in 23 cases (66%), followed by G1P[8] in 4 cases (11%). The total economic cost was 883 euro per case.

CONCLUSION

Active surveillance demonstrated that the burden of nosocomial rotavirus disease is substantial, and G9P [8] was the genotype found most frequently. Following up children after discharge from hospital allowed the discovery of cases of nosocomial RVAGE which are missed in most other studies.

Secular variation in United States rotavirus disease rates and serotypes: implications for assessing the rotavirus vaccination program

BACKGROUND

Since 2006, we have conducted population-based surveillance for rotavirus disease in children seen in hospitals and emergency departments (EDs) in Monroe County, NY (Rochester), Hamilton County, OH (Cincinnati), and Davidson County, TN (Nashville).

METHODS

During the 2006 and 2007 rotavirus seasons, clinical information and stool specimens were obtained from county children who were <3 years presenting with diarrhea and/or vomiting to the hospital or ED of the only children's hospital in each county. Specimens were tested for rotavirus and genotyped, and rates of hospitalization and ED visits were calculated.

RESULTS

While aggregate rotavirus hospitalization rates for the 3 sites were similar in 2006 and 2007 (22.5/10,000 and 26.8/10,000, respectively), individual rates for the 3 counties differed considerably. The rotavirus hospitalization rate in Rochester between 2006 and 2007 increased 3-fold, but decreased by 33% in Cincinnati and 41% in Nashville over the 2 study years. G1 strains accounted for >80% of strains at all 3 sites in 2006. However, in 2007, the uncommon P[8], G12 strain was detected in 69% of Rochester specimens, while the P[8], G1 strain remained predominant in the other 2 sites. No subjects received rotavirus vaccine in 2006 and coverage with 2 to 3 vaccine doses reached 15% in all 3 communities by June 2007.

CONCLUSIONS

During the 2006 and 2007 rotavirus seasons, with only limited vaccine use, remarkable variability was observed in the population-based rates of severe rotavirus and in the rotavirus serotypes across the 3 sites. This natural secular variability in rotavirus disease must be considered in the assessment of the impact of vaccine on disease rates and rotavirus serotypes.

[Post vaccination rotavirus surveillance in Hungary, in 2007]

Vaccination is the main strategy to control severe dehydrating gastroenteritis caused by rotaviruses in early childhood. The availability of new generation rotavirus vaccines has led to an intensification of strain surveillance worldwide, in part, to gauge the impact of the possible vaccine-driven immune selection of wild-type rotavirus strains. In the present study, authors describe the strain prevalence data obtained in 2007, with the involvement of different regions of Hungary. Genomic RNA was extracted from rotavirus-positive stool samples collected mainly from children and then subjected to genotyping using multiplex RT-PCR assay. Type-specific primers targeted G1 to G4, G6, G8 to G10, and G12 VP7 specificities, and P[4], P[6], and P[8] to P[11] VP4 specificities were used. Out of 489 rotavirus-positive specimens, collected from 482 patients, 466 and 474 were successfully G and P typed, respectively, and both G and P type specificities could be assigned for 457 strains. Prevalence data showed the predominance of G4P[8] (31.5%) strains, followed by G1P[8] (28.3%), G2P[4] (19.3%), and G9P[8] (10.2%). Minority strains were G1P[4] (0.4%), G2P[8] (1.3%), G3P[9] (0.2%), G4P[6] (0.7%), G6P[9] (0.4%), G8P[8] (0.2%), G9P[4] (0.2%), G9P[6] (0.8%), and G12P[8] (0.4%). Mixed infections were found in 1.2% of the samples, while 4.9% remained partially or fully non-typified. Our data indicate that the antigen specificities of medically important rotavirus strains identified in this 1-year study are well represented in the vaccines available in the pharmaceutical private market in Hungary. Depending on the vaccination coverage achievable in the forthcoming years, the post-vaccination rotavirus strain surveillance may allow us to gain comprehensive information on the impact of rotavirus vaccines on the prevalence of circulating rotavirus strains.

Are human P[14] rotavirus strains the result of interspecies transmissions from sheep or other ungulates that belong to the mammalian order Artiodactyla?

A limited number of human G6P[14] rotavirus strains that cause gastroenteritis in humans have been isolated in Europe and Australia. The complete genome sequences were determined for five of these human strains--B10925-97 (isolated in Belgium in 1997), 111/05-27 (Italy, 2005), PA169 (Italy, 1987), MG6 (Australia, 1993), and Hun5 (Hungary, 1997)--and their genetic relatedness to animal rotavirus strains was evaluated by sequencing the complete genome of the sheep rotavirus OVR762 (G8P[14]; Spain, 2002), the guanaco (Lama guanicoe) rotavirus strains Arg/Chubut/99 and Arg/Río Negro/98 (G8P[14] and G8P[1], respectively; Argentina, 1999 and 1998), the sable antelope strain RC-18/08 (G6P[14]; South Africa, 2008), and the bovine rotavirus strain Arg/B383/98 (G15P[11]; Argentina, 1998). These analyses revealed an overall consensus genomic constellation (G6/G8)-P[14]-I2-(R2/R5)-C2-M2-(A3/A11)-N2-T6-(E2/E12)-H3, together with a few gene reassortments, and the phylogenetic analyses confirmed that the P[14] human strains evaluated in this study were closely related to rotavirus strains isolated from sheep, cattle, goats, guanacos, and antelopes and to rabbits (albeit to a lesser extent), suggesting that one (or more) of these animal species might be the source of the human G6P[14] strains. The main feature of the genotype and phylogenetic analyses was the close overall genomic relatedness between the five human G6P[14] rotavirus strains and the ovine and antelope rotavirus strains. Taken together, these data strongly suggest a common origin for the human P[14] strains and those of the even-toed ungulates belonging to the mammalian order Artiodactyla, with sheep probably playing a key role in the interspecies transmission responsible for the introduction of P[14] rotavirus strains into the human population.

Emergence of G12 rotavirus strains in Delhi, India, in 2000 to 2007

The prospect that rotavirus diarrhea in children may soon be prevented by vaccines has placed a new priority on understanding the diversity of rotavirus strains and the mechanism by which these strains evolve over time. We have characterized a total of 465 rotavirus strains collected in North India from 2000 to 2007 for G and P types by reverse transcription-PCR and sequencing. The novel G12 rotavirus strains recently detected in other countries were first detected in India in 2001 and have emerged as the predominant strains in Delhi, India, during 2005 to 2007. While the VP7 sequence was highly homologous among G12 strains isolated in Delhi, suggesting recent emergence from a common ancestor, the strains had a diverse constellation of other gene segments, demonstrating substantial reassortment. For the entire period, the common rotavirus G types G1 (26%), G2 (25%), and G9 (14%) comprised 65% of the strains, and common P types, P[4] (19%), P[6] (22%), and P[8] (35%), comprised 76% of the total P types. Of note, we detected a high percentage of unusual (17%) strains and fecal specimens with mixed (12% G and 15% P) rotavirus infections having a variety of genomic constellations. For the first time, we identified two novel rotavirus strains with unusual G/P combinations, G2P[11] and G3P[11], in patients with diarrhea. The study highlights the great diversity among rotaviruses isolated from Indian children, the opportunity for genetic reassortment between strains, and the emergence of a novel G12 strain in our country. Due to the demonstrated effect of antigenic diversity on rotavirus vaccines, it will be important to continue careful monitoring of these strains as rotavirus vaccine programs are implemented in India.

Molecular epidemiology of rotavirus diarrhea among children in Saudi Arabia: first detection of G9 and G12 strains

In anticipation of rotavirus vaccine introduction in Saudi Arabia, this study was undertaken to determine the distribution of the G and P genotypes of rotaviruses in order to examine whether there was any emerging serotype or unusual strain circulating in children in Saudi Arabia. Of 984 stool specimens collected between 17 April 2004 and 16 April 2005, rotavirus was detected by an enzyme-linked immunosorbent assay in 187 (19%) diarrheal children less than 5 years of age. Of these, 160 (86%) were classified into G and P genotypes as follows: G1P[8] (44%), G2P[4] (20%), G9P[8] (11%), G12P[8] (4%), and G3P[8] (4%). RNA polyacrylamide gel electrophoresis identified 94 (50%) specimens as long RNA patterns, 30 (16%) specimens as short RNA patterns, and 1 mixed infection. Only a single long RNA electropherotype was identified for seven specimens containing G12P[8] rotavirus. RNA-RNA hybridization demonstrated that the G12P[8] strains were similar in their genomic constellation to locally cocirculating strains and to a Nepalese G12P[8] strain. The Saudi Arabian G12 VP7 gene had a 99% nucleotide sequence identity with Nepalese and Indian G12 VP7 genes and belonged to the third lineage. This study is the first to describe the distribution of rotavirus G and P types and also the first to identify G9P[8] and G12P[8] strains in the country.