Circulating Rotavirus Strains Research Articles

Distribution of group a Rotavirus circulating in Mashhad, Iran.

Group A Rotavirus (RVA) is the most important causative agent of acute diarrheal disease in pediatrics 5 years and below. This study aimed to determine the distribution of circulating RVA in Mashhad, Iran to develop health improvement strategies and vaccine decision making. A total of 106 fecal specimens were collected from children admitted to Akbar and Dr. Sheikh referral pediatric hospitals of Mashhad City during the December 2020 to March 2021 and December 2021 to March 2022. All specimens were tested for specific bacterial, parasitic, and amoebic infections. Negative samples were analyzed for RVA infections using the RT-PCR method. RVA was detected in 31.3% of the specimens, indicating no statistical significance in gender distribution or between fall and winter positivity rates. The number of RVA-positive specimens increased following age increasing in the range of 1 to 60 months. Today, acute diarrheal disease (ADD) is still caused mostly by Rotavirus infections in pediatrics in Mashhad. Comprehensive studies are needed to determine the genetic diversity of circulating Rotavirus strains in this era.

Vaccine evaluation and genotype characterization in children infected with rotavirus in Qatar

BackgroundWe characterized and identified the genetic and antigenic variations of circulating rotavirus strains in comparison to used rotavirus vaccines.MethodsRotavirus-positive samples (n = 231) were collected and analyzed. The VP7 and VP4 genes were sequenced and analyzed against the rotavirus vaccine strains. Antigenic variations were illustrated on the three-dimensional models of surface proteins.ResultsIn all, 59.7% of the hospitalized children were vaccinated, of which only 57.2% received two doses. There were no significant differences between the vaccinated and non-vaccinated groups in terms of clinical outcome. The G3 was the dominant genotype (40%) regardless of vaccination status. Several amino acid changes were identified in the VP7 and VP4 antigenic epitopes compared to the licensed vaccines. The highest variability was seen in the G3 (6 substitutions) and P[4] (11 substitutions) genotypes in comparison to RotaTeq®. In comparison to Rotarix®, G1 strains possessed three amino acid changes in 7-1a and 7-2 epitopes while P[8] strains possessed five amino acid changes in 8-1 and 8-3 epitopes.ConclusionsThe current use of Rotarix® vaccine might not be effective in preventing the infection due to the higher numbers of G3-associated cases. The wide range of mutations in the antigenic epitopes compared to vaccine strains may compromise the vaccine’s effectiveness.ImpactThe reduced rotavirus vaccine effectiveness necessitate regular evaluation of the vaccine content to ensure optimal protection.We characterized and identified the genetic and antigenic variations of circulating rotavirus strains in comparison to the Rotarix vaccine strain that is used in Qatar.The study highlight the importance for regular monitoring of emerging rotavirus variants and their impact on vaccine effectiveness in young children.

Estimates the Evolution of G8P[8] Rotaviruses in Thailand during 2012 - 2014

Point mutation and abrupt changes of segmented genomes of rotavirus group A (RVAs) from mixed infection are critical factors for generating genetically divergent strains. Our preceding study of rotavirus infections in 2012 - 2014 in Thailand indicated the high prevalence of G8P[8] strains. This study aimed to identify the origin of each segment of the genome of these G8P[8] RVA strains by using phylogenetic analysis. All gene segments from the 5 selected G8P[8] were sequenced partially and aligned with locally circulating rotavirus strains to estimate the phylogenic relationship. Based on the genome's constellation of the genome, these 5 strains’ genetic backgrounds possessed genotype constellation 2 or called the DS-1-like genotype. Ten genes, except for VP6, were clustered within the same phylogenic tree of the cognate genes of Thai circulating G8P[8]strains isolated between 2013 - 2014. Their 5 genes VP2, VP3, NSP1, NSP3, and NSP5, also exhibited high nucleotide similarities with the first unusual Japanese DS-1-like strains G1P[8] NT004. Besides, the VP4 shared a high nucleotide sequence similarity with the cognate gene of circulating Thai human G1P[8] Wa-like and G1P[8] NT004. However, the remaining 4 gene segments (VP1, VP7, NSP2, and NSP4) were clustered with other human or animal RVA strains within the same monophyletic. All of these G8P[8] strains shown to be an intragenogroup reassortment. Thus, characterization of the genomes is crucial to monitor the evolutionary dynamics and relationships of co-circulating RVAs in predicting the effectiveness of current vaccines and future vaccine development strategies.
 HIGHLIGHTS
 
 G8P[8] strains’ genetic backgrounds possessed genotype constellation 2 ( DS-1-like genotype)
 G8P[8] strains might originate from a sequential process of multiple reassortment events involving intra-genogroups from humans and animal species
 Ten genes, except for VP6, were clustered within the same phylogenic tree of the cognate genes of Thai circulating G8P[8]strains isolated between 2013 - 2014
 
 GRAPHICAL ABSTRACT

Genetic diversity of G3 rotavirus strains circulating among children with acute gastroenteritis in Nam Dinh and Thua Thien Hue provinces, Vietnam, 2016 - 2021

Rotavirus (RV) is the most common cause of severe childhood diarrhea worldwide. Since 2006, the WHO has approved the use of two vaccines against Rotavirus (RotaTeq and Rotarix), which has contributed to a significant reduction in morbidity and mortality from this disease in children under 5 years of age. Beside of that, the presence of vaccines could also cause selective pressure among circulating RV strains. Diarrhea samples were a part of the study of the project “Evaluation of rotavirus vaccine effectiveness in Vietnam” and some diarrhea samples were randomly selected from 2010 - 2015 and were stored in our laboratory. Rotavirus antigen in diarrhea samples was detected using the Premier Rotaclone kit. G and P genotypes were determined by RT-PCR using type specific primers. The nucleotide sequencewas determined by next generation sequencing and phylogenetic analysis was performed by the neighbor-joining method. 375/1715 (21.9%) samples detected G3 strain include equine-like G3 (eG3) and human G3 (hG3). The prevalence of G3 strains decreased from 2016 to 2021. All eleven gene segments were typed among 34 samples and substantial diversity among the circulating strains was observed. The circulating G3 strains were also phylogenetically diverse and related to strains from several different countries, different origins such as human (20 samples), pig (1 sample), cat (3 samples) and equine (10 samples). Comparing with the vaccine strains, the antigenic epitopes present on VP7 ofG3 in Vietnam differed considerably, especially the K238N. With the genetic characteristics of the G3 strain, it could contribute to the vaccine effectiveness in Vietnam.

Разнообразие циркулирующих штаммов ротавируса до и после внедрения ротавирусной вакцины

Разнообразие циркулирующих штаммов ротавируса до и после внедрения ротавирусной вакцины

Genotypic characterization of group A rotavirus in children < 5 years of age at tertiary care hospital in North India

PurposeThis study was undertaken to find out the positivity of rotavirus associated diarrhoea in children <5 years of age in Meerut district and to determine the genomic diversity of the circulating rotavirus strains in this geographical area. MethodsA cross-sectional study was conducted in a tertiary care hospital for a period of one year. A total of 240 stool samples were collected from children suffering from acute diarrhoea and subjected for rotavirus antigen detection by enzyme immunoassay (EIA). The EIA-positive samples were further genotyped to determine the G and P types using semi nested multiplex reverse transcriptase-polymerase chain reaction (RT-PCR). Demographic and clinical parameters were recorded in a pre-designed proforma. ResultsThe rotavirus antigen positivity rate was 14.58% in Meerut district. There was male predominance and highest positivity rate was seen in children 13–24 months of age, in winter months and majority of cases belonged to moderate degree of severity. A total of 64% children in the study area were vaccinated and positivity was low in the vaccine group. G9P[4] was the predominant genotype followed by G3P[8]. Uncommon strains G12P[6] and G12P[8] were also reported as circulating genotypes in this study. ConclusionsThe positivity rate of rotavirus associated diarrhoea has reduced in Meerut district post vaccination. G9P[4] was the most common circulating RV genotype in Meerut. Our study highlights the importance of including the emerging rotavirus strains in future multivalent RV vaccines to make the vaccines regionally more specific.

Diversity of Rotavirus Strains in Children; Results From a Community-Based Study in Nepal.

Objective: The objectives of this study were to describe the incidence and genetic diversity of Rotavirus (RV) infection among children up to 3 years of age in a community in Nepal.Methods: We investigated community-acquired cases of asymptomatic and symptomatic RV infections in children from birth to 36 months of age in a community-based birth cohort in Bhaktapur, Nepal. Monthly surveillance and diarrheal stool samples were collected from 240 children enrolled at birth, of which 238 completed the 3 years of follow-up. Samples were screened for rotavirus by Enzyme Immuno Assay (EIA). All RV screened positives were further genotyped by reverse transcription-polymerase chain reaction for the capsid genes VP7 and VP4.Results: In total, 5,224 stool samples were collected from 238 children, followed from birth to 36 months of age. Diarrhea occurred in 92.4% (230/238) of all children in the cohort. During the 3 years study period, RV was more frequently seen in children with symptoms (7.6%) than in non-symptomatic children (0.8%). The highest RV detection rate was found in younger children between 3 and 21 months of age. Although rotavirus is known as winter diarrhea, it was detected throughout the year except in August. The highest positivity rate was observed in the months between December and March, with a peak in January. Four common G types were seen: G2 (30%), G1 (29%), G12 (19%), and G9 (16%). The most predominant genotypes seen were G2P[4] (30%), followed by G1P[8] (27.0%), G12P[6] (14.0%), G9P[8] (10%), and remaining were mixed, partial, and untyped.Conclusion: Our study confirms that rotavirus is a common cause of gastroenteritis in young children in the community. The prevalence and pathogenicity of rotavirus infection differed by age. There was substantial variability in circulating strains in the community samples compared to samples collected from hospitals. This shows the importance of including community-based surveillance systems to monitor the diversity of circulating rotavirus strains in Nepal.

Rotavirus vaccine efficacy up to 2 years of age and against diverse circulating rotavirus strains in Niger: Extended follow-up of a randomized controlled trial.

BackgroundRotavirus vaccination is recommended in all countries to reduce the burden of diarrhea-related morbidity and mortality in children. In resource-limited settings, rotavirus vaccination in the national immunization program has important cost implications, and evidence for protection beyond the first year of life and against the evolving variety of rotavirus strains is important. We assessed the extended and strain-specific vaccine efficacy of a heat-stable, affordable oral rotavirus vaccine (Rotasiil, Serum Institute of India, Pune, India) against severe rotavirus gastroenteritis (SRVGE) among healthy infants in Niger.Methods and findingsFrom August 2014 to November 2015, infants were randomized in a 1:1 ratio to receive 3 doses of Rotasiil or placebo at approximately 6, 10, and 14 weeks of age. Episodes of gastroenteritis were assessed through active and passive surveillance and graded using the Vesikari score. The primary endpoint was vaccine efficacy of 3 doses of vaccine versus placebo against a first episode of laboratory-confirmed SRVGE (Vesikari score ≥ 11) from 28 days after dose 3, as previously reported. At the time of the primary analysis, median age was 9.8 months. In the present paper, analyses of extended efficacy were undertaken for 3 periods (28 days after dose 3 to 1 year of age, 1 to 2 years of age, and the combined period 28 days after dose 3 to 2 years of age) and by individual rotavirus G type. Among the 3,508 infants included in the per-protocol efficacy analysis (mean age at first dose 6.5 weeks; 49% male), the vaccine provided significant protection against SRVGE through the first year of life (3.96 and 9.98 cases per 100 person-years for vaccine and placebo, respectively; vaccine efficacy 60.3%, 95% CI 43.6% to 72.1%) and over the entire efficacy follow-up period up to 2 years of age (2.13 and 4.69 cases per 100 person-years for vaccine and placebo, respectively; vaccine efficacy 54.7%, 95% CI 38.1% to 66.8%), but the difference was not statistically significant in the second year of life. Up to 2 years of age, rotavirus vaccination prevented 2.56 episodes of SRVGE per 100 child-years. Estimates of efficacy against SRVGE by individual rotavirus genotype were consistent with the overall protective efficacy. Study limitations include limited generalizability to settings with administration of oral polio virus due to low concomitant administration, limited power to assess vaccine efficacy in the second year of life owing to a low number of events among older children, potential bias due to censoring of placebo children at the time of study vaccine receipt, and suboptimal adapted severity scoring based on the Vesikari score, which was designed for use in settings with high parental literacy.ConclusionsRotasiil provided protection against SRVGE in infants through an extended follow-up period of approximately 2 years. Protection was significant in the first year of life, when the disease burden and risk of death are highest, and against a changing pattern of rotavirus strains during the 2-year efficacy period. Rotavirus vaccines that are safe, effective, and protective against multiple strains represent the best hope for preventing the severe consequences of rotavirus infection, especially in resource-limited settings, where access to care may be limited. Studies such as this provide valuable information for the planning of national immunization programs and future vaccine development.Trial registrationClinicalTrials.gov NCT02145000.

Immunological and molecular detection of rotavirus genotype in children with gastroenteritis in Diyala-Iraq

Aim: To explore the prevalence along with the molecular detection and genotyping of group A rotavirus (RVA) among children up to 5 years old complaining of gastroenteritis in Diyala province-Iraq. Methods: This is a cross sectional study conducted in Diyala province-Iraq during the period of 2019-2020. One hundred children up to 5 years old with gastroenteritis were enrolled. 54% were males and 46% were females. They were attending hospitals or primary healthcare centers. All were vaccinated with rotavirus vaccine. Blood and fecal samples were collected from each subject. Serum anti-rotavirus IgM and IgG plus fecal rotavirus Ag were tested for using ELISA techniques. Stool samples positive for rotavirus Ag were submitted for conventional PCR and for G and P genotyping thereafter. Statistical analysis was done using SPSS version 25 and P values ≤ 0.05 were considered significant. Results: The anti-rotavirus IgM and IgG positivity rates among children were 71% (P = 0.001) and 81% (P = 0.0001), respectively. Additionally, the rotavirus stool antigen was positive in 75% of the children (P = 0.001). Among 61 stool samples submitted for conventional PCR technique, the rotavirus RNA was detected in 25 (40.9%). The sequencing and genotyping investigation of 10 PCR positive products revealed that all investigated viral samples belonged to G1P[8] rotavirus A genotype. Conclusion: The current strains analyzed belonged to the G1P[8] rotavirus A genotypes, indicating high coverage of current rotavirus vaccines and affirming the importance of continuous characterization of circulating rotavirus strains and monitoring vaccine efficacy.

Emergence of G12P[6] rotavirus strains among hospitalised children with acute gastroenteritis in Belém, Northern Brazil, following introduction of a rotavirus vaccine.

Species A rotavirus still remains a major cause of acute gastroenteritis in infants and young children. Globally, six genotypes (G1P[8], G2P[4], G3P[8], G4P[8], G9P[8] and G12P[8]) account for >90% of circulating strains; however, genotype G12 in combination with P[6] or P[9] has been detected at increasing rates. We sought to broaden our knowledge about the rotavirus strains circulating during the early post-vaccine-introduction period. Stool samples were obtained from children hospitalised for acute gastroenteritis in Belém, Northern Brazil, from May 2008 to May 2011 and examined by reverse transcription polymerase chain reaction and nucleotide sequencing. A total of 122 out of the original 1076 rotavirus strains were judged to be non-typeable in the first analysis and were therefore re-examined. G2P[4] was the most prevalent genotype (58.0%), followed by G1P[8] (16.9%), and G12P[6] (7.5%). G12P[6] strains were identified at similar rates during the first (2.5%) and second (3.9%) years, and the rate jumped to 15.6% in the third year. Analysis of VP7 sequences of the G12P[6] strains showed that they belonged to lineage III. In addition, co-circulating G12P[6] strains displaying long and short RNA patterns were found to belong to the Wa-like and DS-1-like constellation, respectively. Additional unusual circulating strains G12P[9] and G3P[9] were also identified. This hospital-based study showed a high prevalence of G12P[6] strains in the third year of surveillance. Our results highlight the need for continuous longitudinal monitoring of circulating rotavirus strains after introduction of rotavirus vaccines in Brazil and elsewhere.

Human rotavirus in Iran; molecular epidemiology, genetic diversity and recent updates on vaccine advances.

Human rotavirus is the predominant pathogen causing gastroenteritis in infants and children younger than 5 years of age globally. Before introduction and implementation of rotavirus vaccine,more than frothy percent of all caused acute gastroenteritis hospitalization and nearly half a million deaths per year was occurred due to Rotavirus infection mostly in the low-income countries. Rotaviruses are divided in G and P genotypes, based on two genomic segments' nucleotide sequences VP7 and VP4, respectively. Currently, 27 G and 37 P types have been described; among them G1 to G4 and G9 and P[8], P[4], and P[6] genotypes are the most prevalent circulating rotavirus strains globally. Molecular epidemiological surveys revealed that G1P[8] is the predominant genotype in Iran, although other genotypes have also been reported. Rotavirus vaccine was recommended by the World Health Organization as a necessary part of national childhood immunization programs in 2009. Rotarix (monovalent) and RotaTeq (pantavalent) are two oral vaccines that have been available in more than one hundred countries around the world to control the viral infection and reduce the cases of diarrheal diseases. This article provides a review of frequency, molecular epidemiology and current situation of Rotavirus genetic diversity Iran. In addition, recent advances in rotavirus vaccine research are discussed.

Molecular Characterization of Rotavirus Strains Circulating in Enugu Nigeria: 2011 to 2016

Rotavirus gastroenteritis is a major public health concern globally, estimated to cause 215,000 deaths among children < 5 years of age in 2013; with majority of mortality occurring in developing countries. In 2013, it was estimated that Nigeria was the second country with the highest number of rotavirus deaths. Monitoring of circulating rotavirus strains in Enugu, Nigeria is part of on-going rotavirus surveillance before the introduction of rotavirus vaccination. A total of 2694 stool samples were collected from enrolled under 5 years old children with diarrhoea between January 2011 and December 2016 and tested the virus using an antigen enzyme immunoassay. Randomly selected rotavirus positive samples were further characterized by rotavirus genotype methods to identify the G and P types circulating during the study period. Rotavirus was detected in 1242 (46%) of the 2694 samples collected over the six years period. Of these, 867 were randomly selected for genotyping. G and P types could be assigned for 832 samples (96%), while 31 (3.6%) could only be assigned either genotype G or P (partially typed) and 4 (0.4%) could not be assigned genotype G and P (untypeable). The most common G-genotypes detected during the entire study period were G12, G1 and G3 accounting for 27.6%, 21.0% and 16.3% respectively. Mixed G and P-genotypes were commonly detected. Ninety-one of the samples, representing 10.8% (91/839) had mixed G-genotype whilst 130 of the samples representing 15.2% (130/852) had mixed P-genotype. The most common P-genotypes detected were P[8], P[6] and P[4] representing 38.3%, 35.4% and 9.1% respectively. The predominant strain detected was G12P[8] (22.3%) followed by G3P[6] (14.5%), G1P[8] (9.2%) and G1P[6] (8.0%). These data are useful for making an informed decision about the introduction of rotavirus vaccine into the national routine immunization program and to monitor the impact of the vaccine post licensure.

Hospital based surveillance and molecular characterization of rotavirus in children less than 5 years of age with acute gastroenteritis in Nepal

BackgroundRotavirus remains a significant causative agent of childhood acute gastroenteritis, particularly among children less than 5 years of age. Although precise data on childhood mortality associated with diarrheal disease in Nepal is not available, it is estimated that22% of all rotavirus deaths globally occurs in neighboring country of India. In spite of the substantial burden of rotavirus gastroenteritis in the Indian subcontinent, rotavirus vaccine has not been introduced in Nepal. Continuous surveillance for monitoring rotavirus disease burden and molecular characterization is needed prior to rotavirus vaccine introduction in Nepal. MethodsA total of 3310 stool samples (2849 hospitalized cases and 461 non-hospitalized cases), were collected from patients <5 years of age from January 2013 to December 2016 and tested for rotavirus antigen by ELISA (ProSpecT, USA). A subset of ELISA positive stool samples was genotyped. Demographic data were collected. ResultsDuring the four-year surveillance period, the overall burden of rotavirus infection was 24% among hospitalized children which was much higher than among non-hospitalized children (12%). The majority of children hospitalized with rotavirus gastroenteritis were less than 2 years of age (86%). Rotavirus-associated gastroenteritis hospitalizations occur year-round in Nepal, but a distinct peak in winter (up to 40% among hospitalized) was observed. Of 735 ELISA positive samples, 492 were genotyped by RT-PCR. The most prevalent genotype was G12P[6] (45.3%), followed byG2P[4](12.2%), G1P[8] (9.6%), G9P[4](7.3%), and G9P[8](4.5%). Mixed infection accounted for 4.4% of cases, 6.2% were partially typed and 10.5% of the samples were G and P untypable. ConclusionsA high burden of rotavirus gastroenteritis and a diversity of circulating rotavirus strains in Nepal were observed. Recommendation to introduce a rotavirus vaccine with known vaccine effectiveness would help in reducing the severity of Rotavirus diarrheal disease in children less than 5 years of age.

Prevalence of rotavirus and rapid changes in circulating rotavirus strains among children with acute diarrhea in China, 2009–2015

Rotavirus is a leading cause of morbidity and mortality in young children worldwide. In China, the universal immunization of children with the rotavirus vaccine has not been introduced, and the two globally distributed vaccines (RotaTeq and Rotarix) are not licensed in the country. We aim to determine the prevalence and strain diversity of rotavirus in children with diarrhea aged≤five years across China. Sentinel-based surveillance of acute diarrhea was conducted at 213 participating hospitals in China from January 1, 2009, through December 31, 2015. Group A rotavirus (RVA) was tested by using enzyme-linked immunosorbent assays, and G- and P-genotype of RVA were tested by RT-PCR methods. Of 33,616 children with diarrhea, 10,089 (30%) were positive for RVA; RVA-associated diarrhea was identified in 2247 (39.5%, n = 2247/5685) inpatients and 7842 (28.1%, n = 7842/27931) outpatients. Children living in low-middle-income regions suffered from the highest burden of rotavirus, with 40.7% of diarrhea cases attributed to rotavirus infection, followed by 31.3% in upper-middle-income and 11.2% in high-income regions. The majority of children (88.9%, n = 8976/10089) who tested positive for RVA were children aged≤2 years. The seasonal peak of RVA was in the winter. Among all 2533 RVA strains genotyped, five strain combinations, G9P[8], G3P[8], G1P[8], G2P[4] and G3P[4], contributed to 71.3% (1807/2533) of the RVA-associated diarrhea cases. The predominant strain of RVA has rapidly evolved from G3P[8] and G1P[8] to G9P[8] in the recent years, with the proportion of G9P[8] having increased remarkably from 3.4% in 2009 to 60.9% in 2015. The burden of diarrhea attributed to rotavirus is high in China, highlighting the potential value of vaccination. The rapid shift of RVA strains highlights the importance of conducting rotavirus surveillance to ensure that currently marketed vaccines provide protective efficacy against the circulating strains.

Diversity of rotavirus strains circulating in children under five years of age who presented with acute gastroenteritis before and after rotavirus vaccine introduction, University Teaching Hospital, Lusaka, Zambia, 2008–2015

BackgroundFollowing the introduction of rotavirus vaccine into the routine immunization schedule, the burden of rotavirus disease has significantly reduced in Zambia. Although rotavirus vaccines appear to confer good cross-protection against both vaccine and non-vaccine strains, concerns about strain replacement following vaccine implementation remain. We describe the diversity of the circulating rotavirus strains before and after the Rotarix® vaccine was introduced in Lusaka from January 2012. MethodsUnder five children were enrolled through active surveillance at University Teaching Hospital using a standardized WHO case investigation form. Stool samples were collected from children who presented with ≥3 loose stool in 24 h and were admitted to the hospital for acute gastroenteritis as a primary illness. Samples were tested for group A rotavirus antigen enzyme-linked immunosorbent assay. Randomly selected rotavirus positive samples were analysed by reverse transcription polymerase chain reaction for G and P genotyping and and Nucleotide sequencing was used to confirm some mixed infections. ResultsA total of 4150 cases were enrolled and stool samples were collected from 4066 (98%) children between 2008 and 2011, before the vaccine was introduced. Rotavirus antigen was detected in 1561/4066 (38%). After vaccine introduction (2012 to 2015), 3168 cases were enrolled, 3092 (98%) samples were collected, and 977/3092 (32%) were positive for rotavirus. The most common G and P genotype combinations before vaccine introduction were G1P[8] (49%) in 2008; G12P[6] (24%) and G9P[8] (22%) in 2009; mixed rotavirus infections (32%) and G9P[8] (20%) in 2010, and G1P[6] (46%), G9P[6] (16%) and mixed infections (20%) in 2011. The predominant strains after vaccine introduction were G1P[8] (25%), G2P[4] (28%) and G2P[6] (23%) in 2012; G2P[4] (36%) and G2P[6] (44%) in 2013; G1P[8] (43%), G2P[4] (9%), and G2P[6] (24%) in 2014, while G2P[4] (54%) and G2P[6] (20%) continued to circulate in 2015. ConclusionThese continual changes in the predominant strains suggest natural secular variation in circulating rotavirus strains post-vaccine introduction. These findings highlight the need for ongoing surveillance to continue monitoring how vaccine use affects strain evolution over a longer period of time and assess any normal seasonal fluctuations of the rotavirus strains.

Genotypic characterization of rotavirus in children under 5 years circulating in C\xf4te D\u2019Ivoire from 2010 to 2013

BackgroundRotavirus infection is the most common cause of severe gastroenteritis in children under five years of age in both developed and developing countries. The World Health Organisation (WHO) recommends the surveillance of rotavirus strains prior to vaccine introduction in all applicable countries. The objective of this study was to describe the epidemiological characteristics as well as to determine the circulating genotypes of rotaviruses in Côte d’Ivoire prior to vaccine introduction.MethodsThe study included children under five years of age who met the inclusion criteria after informed consent had been sort from their parents or guardians. Rotavirus VP6 antigens were detected for each stool sample using Enzyme Immunoassay (EIA). Genotyping of positive EIA samples was performed by reverse-transcriptase-PCR (RT-PCR) assays.ResultsA total of 684 children were recruited. Children aged between 6 and 11 months were the most represented with 34%. Rotavirus VP6 antigens were found in 27.1% (186/684) of samples tested. Commonly detected G genotypes included G12 (46.6% (82/176) and G1 (13.1% (23/176) whilst P[8] (49.8% (91/183) was the most predominant P genotype. Rotavirus G12P[8] was the most predominant strain circulating in Côte d’Ivoire within the period of study and constituted 26.6% of all strains detected.ConclusionThe monitoring of circulating strains will help guide decision-makers in the choice of vaccine. Genotypic variability of circulating rotavirus strains over the years implies there is a need for continuous rotavirus strain surveillance even after vaccine introduction.

Rotavirus strain distribution in Ghana pre- and post- rotavirus vaccine introduction

BackgroundGhana introduced the monovalent rotavirus vaccine (Rotarix) into its national paediatric vaccination programme in May2012. Vaccine introduction was initiated nationwide and achieved >85% coverage within a few months. Rotavirus strain distribution pre- and post-RV vaccine introduction is reported. MethodsStool samples were collected from diarrhoeic children <5 years of age hospitalized between 2009 and 2016 at sentinel sites across Ghana and analyzed for the presence of group A rotavirus by enzyme immunoassay. Rotavirus strains were characterized by RT-PCR and sequencing. ResultsA total of 1363 rotavirus EIA-positive samples were subjected to molecular characterization. These were made up of 823 (60.4%) and 540 (39.6%) samples from the pre- and post-vaccine periods respectively. Rotavirus VP7 genotypes G1, G2 and G3, and VP4 genotypes P[6] and P[8] constituted more than 65% of circulating G and P types in the pre–vaccine period. The common strains detected were G1P[8] (20%), G3P[6] (9.2%) and G2P[6] (4.9%).During the post-vaccine period, G12, G1 and G10 genotypes, constituted more than 65% of the VP7 genotypes whilst P[6] and P[8] made up more than 75% of the VP4 genotypes. The predominant circulating strains were G12P[8] (26%), G10P[6] (10%) G3P[6] (8.1%) and G1P[8] (8.0%). We also observed the emergence of the unusual rotavirus strain G9P[4] during this period. ConclusionRotavirus G1P[8], the major strain in circulation during the pre-vaccination era, was replaced by G12P[8] as the most predominant strain after vaccine introduction. This strain replacement could be temporary and unrelated to vaccine introduction since an increase in G12 was observed in countries yet to introduce the rotavirus vaccine in West Africa. A continuous surveillance programme in the post-vaccine era is necessary for the monitoring of circulating rotavirus strains and the detection of unusual/emerging genotypes.

Farmed and companion animals as reservoirs of zoonotic rotavirus strains

Abstract Rotavirus (RV) infections are a major epidemiological problem in humans and farm animals. So far, a number of human and animal RV strains have been identified. Based on the antigenic properties of the VP6 capsid protein, they have been classified into eight serogroups (A-H). The most important of them are viruses from group A (RVA), which are responsible for more than 90% of cases of rotaviral diarrhoea. The segmented structure of the virus genome and the presence of animals in human neighbourhood favour genetic reassortment between RV strains originating from different hosts. This could result in an emergence of zoonotic virus strains. The increasing number of human infections caused by virus strains having genotypes which have only been identified in animals indicates the need for epidemiological surveillance of infections. Additionally, the identification of epidemic virus strains in the outbreaks of disease in humans should be conducted. The identification of RVA strains circulating in humans and animals will allow the assessment of the impact of vaccination on the selection and emergence of zoonotic RVA strains. 1. Introduction. 2. General characteristics and classification of rotaviruses. 3. Group A rotavirus infection in humans. 4. Group A rotavirus infection in animals. 5. Genetic changes and reassortment as factors leading to the formation of zoonotic rotavirus strains. 6. Impact of human immunization on changes in genotype profile of circulating rotavirus strains. 7. Conclusions

English

Group A rotaviruses are the major viral agent of acute gastroenteritis and severe diarrhea in children <5 years old. The World Health Organization (WHO) recommends surveillance of circulating strains before and after introduction of vaccination in countries. However, the diversity of circulating strains in developing countries is a major challenge to the vaccination programs. This study, carried out in furtherance of the sentinel surveillance, aims to identify the different genotypes circulating before the introduction of the Rotavirus vaccine. All children with acute gastroenteritis aged 0 to 5 years, admitted in one of the sentinel surveillance collection sites were included in the study. The study period was from January 2010 to December 2016. Rotavirus was detected in stool specimens by enzyme-linked immunosorbent assay (ELISA). Rotavirus G and P types were determined by real-time polymerase chain reaction (RT-PCR). A total of 1472 stool samples were collected during this period. 31.8% of the stools were rotavirus positive by ELISA test. G1 was predominant with 39.6% followed by G12 (27%). P [8] was 50.4%. The predominant genotype combinations were G1P [8] with 26.1%; G12P [8], 15%; G1P [6], 11.3% and G12P [6], 10.8%. Genotyping of circulating rotavirus strains is important in monitoring strains before and after the introduction of the vaccine. With previous observations, these findings will contribute to baseline data to further monitor the impact of rotavirus immunization in Cote d’Ivoire. Key words: Rotavirus, Cote d’Ivoire, diarrhea, vaccination, acute gastroenteritis.

Circulating rotavirus genotypes in the Irish paediatric population prior to the introduction of the vaccination programme.

Rotavirus is the leading cause of viral gastroenteritis in children, and it is anticipated that the introduction of the Rotarix™ vaccine (GlaxoSmithKline Biologicals S.A., Rixensart, Belgium) into the Irish immunisation schedule will result in a significant reduction of rotavirus-associated disease. In the pre- and post-vaccination eras, it is important to determine circulating strains of rotavirus to assess vaccine effectiveness, to monitor vaccine failures, and to detect potential emerging strains. This study was a collaboration between the Temple Street Children's University Hospital (TSCUH), Dublin, and the National Virus Reference Laboratory (NVRL), Dublin, to determine the then circulating rotavirus strains in a paediatric hospital. In the 2015/2016 period (July 2015-June 2016) 89 faecal samples from paediatric patients (53 from TSCUH, 36 from other hospitals) were characterised. The results showed G1P[8] to be the predominant genotype (57%), followed by G9P[8] (34%), G4P[8] (6%), G2P[4] (2%), and G12P[8] (1%). This distribution of genotypes is comparable to those found in other European countries prior to vaccination suggesting that the vaccine should be highly efficacious in the Irish population.