Diversity of circulating rotavirus strains in children hospitalized with diarrhea in India, 2005-2009

Post-introduction evaluation (PIE) of rotavirus vaccine in India

Background

India became the first country in the WHO South-East Asia Region (SEAR) to introduce the rotavirus vaccine (RVV) in the Universal immunization programme (UIP) in 2016 with nationwide expansion by 2019. It was a landmark move to reduce the diarrheal disease burden in under-five children. To assess the implementation process of introduction of RVV, Post Introduction Evaluation (PIE) was conducted in March 2022.

Methods

The evaluation was conducted across 14 states, 28 districts and 28 health facilities to obtain a nationwide geographical inclusion. Stakeholders involved in program decision-making, planning, training, vaccine delivery, logistics, and communication from all levels (National, state, district, health facility, health worker, caregiver) were interviewed using standardized data collection tool for PIE (adapted from the standard WHO PIE questionnaire) and scripted on a digital tool.

Results

A total of 260 interviews were conducted. Political willingness, well-planned preparedness activities, securing vaccines timely, strong supply chain monitoring, availability of domestic RVV products, quality trainings and intense communication activities were the key factors identified for the successful RVV introduction. Key activities during the introduction included cold chain space assessment, trainings of healthcare workforce, dissemination of job aids, updation of recording & reporting formats and strengthening of AEFI surveillance. Lack of community awareness for immunization in a few areas, fear of AEFI amongst some caregivers and local issues with Alternate Vaccine Delivery (AVD) were some reported challenges in achieving high coverage for RVV.

Conclusions

Overall, the nationwide roll-out of RVV was smooth and the vaccine has been well-accepted in the community. The assessment emphasizes on having a well-strategized operational and communication planning, which is very crucial for any new vaccine introduction.

Whole-genome characterization of common rotavirus strains circulating in Vellore, India from 2002 to 2017: emergence of non-classical genomic constellations

Rotaviruses (RVs) are the most common etiological agent of acute gastroenteritis among young children, even after vaccine introduction in low-income countries. A whole-genome classification representing the 11 RV genes, was introduced for surveillance and characterization of RVs. This study characterized the common circulating strains in Vellore, India from 2002 to 2017 to understand rotavirus strain diversity and evolution using Whole genome sequencing (WGS) carried out on Illumina MiSeq. The 89% (92% of Wa-like, 86% of DS-1-like) of strains had classical constellations, while reassortant constellations were seen in 11% (8% of Wa-like, 14% of DS-1-like) of the strains. The rare E6-NSP4 in combination with DS-1 like G1P[8] and the emergence of the OP-354 subtype of P[8] were identified. Phylogenetics of RV strains revealed multiple subtypes circulating in the past 15 years, with strong evidence of animal to human gene transmission among several strains.

Comparative Analysis of Enzyme-Linked Immunosorbent Assay and Immunochromatography for Rotavirus and Adenovirus Detection in Children below Five Years with Acute Gastroenteritis

Introduction The most frequent etiologies of viral gastroenteritis among young children are rotavirus and enteric adenovirus. The clinical signs and symptoms of viral gastroenteritis are not distinct enough to allow for diagnosis. For the diagnosis and treatment of acute gastroenteritis, it is preferable to use quick, simple, and low-cost procedures. This study was undertaken to determine efficacy of immune-chromatography test (ICT) in comparison with enzyme-linked immunosorbent assay (ELISA) to detect rotavirus and adenovirus antigen in fecal specimen among children less than 5 years of age with acute gastroenteritis.

Materials and Methods In a cross-sectional observational study, 314 fecal samples were collected from children aged less than 5 years with acute gastroenteritis attending or admitted to a tertiary care hospital during the 1 year study period. Samples were tested for rotavirus and adenovirus antigen using ICT and ELISA.

Results Among the 314 children evaluated, 112 (35.66%) had rotavirus infection, nine (2.86%) had adenovirus infection, and three (0.95%) had both rotavirus and adenovirus infection. This study found that ICT is 98.20% sensitive and 100% specific for the diagnosis of rotaviral diarrhea and 100% sensitive and 99.7% specific for adenovirus diarrhea, compared to ELISA.

Conclusion Immunochromatography tests used for the detection of rotavirus and adenovirus in the fecal sample showed a high degree of sensitivity and specificity. The ICT is easy to perform and rapid, and it does not require any special equipment. Hence, the ICT could be used as an alternative method for detecting viral pathogens in clinical practice.

Clinical Profile and Characterization of Rotavirus Strains in Under-Five Children with Diarrhea: A Hospital-Based Study from Eastern Odisha, India

Objective Diarrheal diseases are one of the most common causes of hospitalization in children under five. Rotavirus is the most common cause of acute diarrhea in younger children, and the prevalence decreases rapidly with increasing age. The objective of the study was to estimate the burden of rotavirus infection in acute gastroenteritis among under-five children admitted to a tertiary care hospital in eastern Odisha, for the clinical profile and identity of the prevalent strains.

Methods This was a prospective observational study linked to the National Rotavirus Surveillance Network (NRSN), where 720 under-five children with diarrhea were enrolled. In total, 675 stool samples of eligible candidates were sent for rotavirus isolation, and identification of strains was done by identifying VP7 (G-type) and VP4 (P-type) genes by reverse transcription polymerase chain reaction.

Results Categorical variables were presented as frequency and percentage, and continuous variables were expressed as mean ± standard deviation. Rotavirus was detected in 256 (37.92%) samples. Males outnumbered females. The most common affected age group was 7 to 12 months, followed by 13 to 18 months. G3P[8] was the most prevalent strain in this study.

Conclusion Children between the age of 7 and 18 months were most vulnerable to rotavirus infection. The most prevalent strain varies from one region to another and continuous surveillance is needed.

Rotavirus vaccines performance: dynamic interdependence of host, pathogen and environment

INTRODUCTION

As of January 2021, rotavirus vaccination programs have been implemented in 109 countries and their use has resulted in a positive impact on rotavirus-related diarrheal hospitalizations and mortality in children below 5 years of age. Despite these successes, several countries in Africa and Asia where disease burden is high have not yet implemented rotavirus vaccination at all or at a scale sufficient enough to demonstrate impact. This could be, among other reasons, due to poor vaccine coverage and the modest levels of efficacy and effectiveness of the vaccines in these resource-limited settings.

AREAS COVERED

We review various factors related to the human host (malnutrition, maternally derived antibodies and breastfeeding, genetic factors, blood group, and co-administration with oral polio vaccine), rotavirus pathogen (force of infection, strain diversity and coinfections), and the environment (related to the human microbiome) which reflect complex and interconnected processes leading to diminished vaccine performance in resource-limited settings.

EXPERT OPINION

Addressing the limiting factors for vaccine efficacy is needed but likely to take a long time to be resolved. An immediate solution is to increase the immunization coverage to higher values generating an overall effect of adequate proportion of protected population to reduce the prevalence of rotavirus disease.

Phylogenetic analysis of VP7 and VP4 genes of the most predominant human group A rotavirus G12 identified in children with acute gastroenteritis in Himachal Pradesh, India during 2013-2016

G12 strains are now considered to be the sixth most prevalent human rotaviruses globally. India has introduced rotavirus vaccine Rotavac® into the national immunization program in 2016 and Himachal Pradesh (HP) is the first state to launch it. During epidemiological rotavirus surveillance in HP, predominance of G12 rotaviruses was observed. This study investigated the genetic variability and evolution of HP G12 strains (n = 15) associated with P-genotypes P[6], P[4], and P[8] identified between 2013 and 2016. Phylogenetic analysis of VP7 gene revealed that all characterized G12 strains clustered in lineage-III and diversified into three subclusters indicating that these strains may have originated from three different ancestral G12 strains. The comparative sequence analysis of HP strains with Rotavac® and Rotarix® vaccine strains revealed various amino acid substitutions in epitope regions of VP7 and VP4 proteins especially at the antibody neutralization sites. Only 12/29 VP7 epitope residues and 2/25 VP4 epitope residues were found to be conserved between HP rotavirus strains and vaccine strains. Both long and short electropherotypes were observed in G12P[4] strains, while a single long electropherotype was observed in G12P[6] strains. Children of ≤11 months were significantly infected with G12 rotaviruses. The frequency of vomiting episodes (≥5/day) was significantly higher in children infected with G12 rotavirus strains as compared to non-G12 rotaviruses (p = 0.0405). Our study provides the comprehensive data on clinical characteristics and evolutionary pattern of the G12 rotavirus, the most prevalent strain in HP and emphasizes the need to monitor these strains for inclusion in future vaccine.

A review of rotavirus vaccine use in Asia and the Pacific regions: challenges and future prospects

Introduction: Rotavirus infection causes a significant proportion of diarrhea disease burden in children <5 years of age in Asia and the Pacific regions. The World Health Organization recommends that rotavirus vaccination should be included in national immunization programs to prevent rotavirus gastroenteritis (RVGE).Areas covered: A literature review was performed to identify and summarize published evidence on RVGE epidemiology and status of rotavirus vaccine use, including the impact and cost-effectiveness of rotavirus vaccination programs in Asia and the Pacific regions (49 countries) during the period 2000-2018.Expert opinion: Rotavirus vaccination programs have successfully reduced the burden of RVGE in many countries. However, such programs still do not exist in most Asia-Pacific countries, and therefore the burden of RVGE remains high in children <5 years of age. Challenges to vaccine implementation include a lack of surveillance data; safety concerns around intussusception; a general lack of awareness about RVGE disease epidemiology and vaccines among physicians, policy-makers, and parents; insufficient cost-effectiveness analyses; and potential issues with vaccine affordability including vaccination costs and lack of political will. Recommendations to overcome these challenges include developing cost-effectiveness analyses for more diverse national and regional settings, providing non-governmental support for low-income countries, and improving advocacy efforts.Plain language summaryWhat is the context?• Rotavirus (RV) infection causes acute gastroenteritis (GE) in children under 5 years of age.• Rotavirus vaccination (RVV) implementation has been slow in Asia and the Pacific (AP) regions, which could be responsible for the region falling behind in their fight against RVGE.What is new?• RVV via national immunization programs (NIPs) is available in 8/49 countries and through the private market or non-governmental support in other countries. Coverage rates vary between countries, possibly driven by the mechanism through which RVV is available.• A substantial positive impact of RVV on RVGE disease burden with a very low risk of intestinal intussusception for up to 7 days after RVV has been documented in the AP regions.• Economic evaluation studies, mainly cost-effectiveness analyses, predict a significant reduction in treatment costs related to RVGE and its complications showing that RVV is good value for money.What is the impact?• The prospect of continued safe and effective use of RVV in the AP regions is promising.• Challenges to RVV implementation include establishing evidence of burden of disease, poor awareness of rotavirus vaccines, limited evidence from cost-effectiveness analyses from several countries, issues of affordability of the vaccine and a lack of political will.• Recommendations for RVV implementation into the NIPs include conducting clinical and cost-effectiveness studies in countries where these are not available, establishing reliable surveillance mechanisms, providing non-governmental support for low-income countries and improving advocacy efforts.• Maintenance of high vaccination coverage is needed in countries that have implemented national RVV programs.Graphical abstract[Formula: see text].

Tate J, D. Parashar U, Kang G. Rotavirus Strain Distribution before and after Introducing Rotavirus Vaccine in India

In April 2016, an indigenous monovalent rotavirus vaccine (Rotavac) was introduced to the National Immunization Program in India. Hospital-based surveillance for acute gastroenteritis was conducted in five sentinel sites from 2012 to 2020 to monitor the vaccine impact on various genotypes and the reduction in rotavirus positivity at each site. Stool samples collected from children under 5 years of age hospitalized with diarrhea were tested for group A rotavirus using a commercial enzyme immunoassay, and rotavirus strains were characterized by RT-PCR. The proportion of diarrhea hospitalizations attributable to rotavirus at the five sites declined from a range of 56–29.4% in pre-vaccine years to 34–12% in post-vaccine years. G1P[8] was the predominant strain in the pre-vaccination period, and G3P[8] was the most common in the post-vaccination period. Circulating patterns varied throughout the study period, and increased proportions of mixed genotypes were detected in the post-vaccination phase. Continuous long-term surveillance is essential to understand the diversity and immuno-epidemiological effects of rotavirus vaccination.

Epidemiology of Intussusception Hospitalizations in Children Under 2 Years of Age Post Rotavirus Vaccine Introduction in Tamil Nadu and Puducherry, India

OBJECTIVE

High burden of rotavirus associated diarrhea has been documented among Indian children. The phased introduction of an indigenous rotavirus vaccine 'ROTAVAC' in India's national immunization programme began in 2017. Phase-III trial showed the vaccine to have a low-intussusception-risk profile. However, evaluation of post-licensure trends of intussusception is necessary to assess potential vaccine-associated intussusception risk. This study's objective was to describe the epidemiology of intussusception hospitalizations in children under two years of age in Tamil Nadu and Puducherry following ROTAVAC introduction.

METHODS

A cross-sectional surveillance was established in six hospitals in Tamil Nadu and Puducherry. Children under two years of age with intussusception fulfilling Brighton Collaboration's criteria for level 1 diagnostic certainty were enrolled. Patient and disease characteristics were captured using a standardized questionnaire. Descriptive and inferential statistical analyses were performed using Stata Version 13.

RESULTS

Overall, 287 cases were enrolled and had a median age of seven months. Frequently presenting symptoms were vomiting (78%), abdominal pain (76%), and blood in stool (71%). Abdominal ultrasonography or radiography confirmed diagnosis in 65% of cases and managed by nonoperative measures. Remaining 35% of cases were diagnosed and managed with surgery. Over 98% of the cases had positive treatment outcomes. Age less than five months (OR = 4.36), and hospitalization at a state government health facility (OR = 5.01) were significant predictors for children to receive surgical management.

CONCLUSIONS

The present study documents the epidemiology of intussusceptions immediately after the rollout of rotavirus vaccine in Tamil Nadu and Puducherry. No appreciable increase in intussusception hospitalizations was seen in the study hospitals after vaccine introduction.

Demographic Profile and Genotypic Distribution of Rotavirus Gastroenteritis from Rural Haryana, India

OBJECTIVE

To know the prevalence of rotavirus among hospitalized <5 y children, their demographic profile and genotypic distribution of rotavirus strain from tertiary care center of rural Haryana.

METHODS

An observational 3-year study done from June 2016 to June 2019 where children under 5 y of age hospitalized for acute gastroenteritis were enrolled. Various demographic, environmental, and clinical parameters were assessed. Stool samples were collected and sent to CMC, Vellore for rotavirus screening by enzyme immune assay (EIA) and RV-positive samples were genotyped using reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

Out of 444 stool sample screened, 107 were positive (24.1%) for rotavirus. RV positive cases seen mostly in 6-24 mo age group with moderate to severe dehydration at presentation and peaks in winter months (Dec - Feb). G3P[8] (35.24%) is the most prevalent genotype identified followed by G1P[8] (20.95%), G1P[6] (11.43%), G2P[4] (6.67%) and G12P[8] (2.86%).

CONCLUSION

Continuous surveillance is required to monitor the circulating genotypes in postvaccination phase and assess the effectiveness and impact of the vaccine.

Rotavirus Diarrhea in Hospitalized Under-5 Children in Madhya Pradesh, India and the Prevalent Serotypes After Vaccine Introduction

OBJECTIVE

To report epidemiology of rotavirus gastroenteritis among under-five children hospitalized for acute diarrhea after the introduction of vaccine in Madhya Pradesh.

METHODS

Children hospitalized for diarrhea between August 2017 and December 2019 were recruited. Stool sample was collected and shipped to Christian Medical College (CMC), Vellore maintaining proper cold chain. Samples were then screened for rotavirus using enzyme immunoassay (EIA). The samples that were positive for rotavirus were further genotyped by reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

Of the 794 stool samples collected, 150 (18.8%) samples were positive for rotavirus. Highest positivity was seen in winter months and in children less than 2 y of age. G3P[8] was found to be the most prevalent serotype.

CONCLUSIONS

The study highlights lowering prevalence of rotavirus gastroenteritis in the authors' region post vaccine introduction. It also highlights the change in prevalent serotypes.

Two-Year Prevalence of Rotavirus Among Under-Five Children Admitted with Acute Gastroenteritis in Andhra Pradesh, India

OBJECTIVE

To estimate the burden of rotavirus diarrhea among under-five children admitted with acute gastroenteritis and to identify genotypes of rotavirus among positive rotavirus cases.

METHODS

This is a cross-sectional study conducted from August 2017 to July 2019 in Government General Hospital and 5 private pediatric nursing homes (Padma Children's Hospital, Mother and Child Hospital, Chandamama Children's Hospital, Vennela Hospital) in Kakinada. Children admitted to the pediatric ward with acute gastroenteritis were included in this study. Stool samples were collected from all these children and tested for rotavirus by enzyme-linked immunosorbent assay and the positive samples were genotyped using reverse transcriptase polymerase chain reaction.

RESULTS

Rotavirus diarrhea was seen in 7.4% of children among all diarrhea admissions. The mean age of the rotavirus-positive children was 13.1 ± 10 mo. The most common genotype in 2017 was G3P[8], and that in 2018 and 2019 was the mixed genotype.

CONCLUSION

In this study, mixed genotype was found to be most common.

Surveillance and Molecular Characterization of Rotavirus Strains Circulating in Odisha, India after Introduction of Rotavac

OBJECTIVE

To know the rotavirus burden associated with acute gastroenteritis along with circulating genotypes among under-five children and to find out possible associations with different demographic and clinical predictors in a tertiary care teaching hospital in Bhubaneswar, Odisha.

METHODS

A prospective acute gastroenteritis surveillance conducted from February 2016 to June 2019 at a tertiary care pediatric hospital in Bhubaneswar has enrolled 850 children under five years of age. The stool samples were tested for VP6 antigen of rotavirus by enzyme immunoassay (EIA) and hemi-nested multiplex PCR to find out VP7 (G type) and VP4 (P type) genes. The data was presented using mean ± SD, median (IQR) along with frequencies and percentages.

RESULTS

Rotavirus positivity was found in 246 children (28.9%) with male: female ratio of 3:1. An increasing trend of rotaviral diarrheal cases was seen during the winter months. History of vomiting for 2 d, age group of 12-23 mo, and fever were significantly associated with rotavirus diarrhea having odd ratios of 1.80 (95% CI, 1.48, and 1.69, respectively). Among the genotypes, G3 and P8 were found to be most common in the present study.

CONCLUSION

With the introduction of Rotavac in the state the overall rotaviral distribution has significantly changed. Children of 6-23 mo were the most affected age group in the study indicating the necessity of this vaccine in the early months of life.

Post Vaccination Epidemiology and Genotyping of Rotavirus Gastroenteritis at a Tertiary Care Centre of North-East Rajasthan

OBJECTIVES

To estimate the proportion of rotavirus diarrhea among hospitalized children aged under-five years, to determine the circulating rotavirus genotypes and to know impact rotavirus vaccine on prevalence and severity of rotavirus diarrhea.

METHODS

This study was a hospital based cross-sectional observational study conducted over a period of 29 mo (September 2017 through January 2020). Stool samples were collected from children who fall within the age range of 0-59 mo with acute diarrhea attending emergency or needing admission. Stool samples were tested for rotavirus by the enzyme linked immune-sorbent assay (ELISA) and genotyped using published methods.

RESULTS

Out of 1480 samples, 360 (24.32%) cases were positive for rotavirus by ELISA, majority of them were male (62.97%). Maximum rotavirus positivity was found in the age group of <11 mo (55.27%). Statistically significance difference was seen in episodes of diarrhea and experience of vomiting in rotavirus diarrhea cases. Highest prevalence has been seen during winter season. The most prevalent G and P type combinations were G3P [8] strains [122 (34.08%)], G2P [4] [83 (23.18%)], G1P [8] [27 (7.54%)] and G9P [4] [20 (5.59%)]. Mixed strains contribute a significant proportion of stool sample.

CONCLUSIONS

Rotavirus is an important cause of diarrhea in hospitalized children. There is continued circulation of G9 and G12 strains and the emergence of G3P [8] as most common strain.

Rotavirus Gastroenteritis in Western Uttar Pradesh, India

OBJECTIVE

To establish hospital-based surveillance to identify cases of rotavirus (RV) among children < 5 y of age hospitalized for acute gastroenteritis (AGE) and to determine the burden and profile of circulating RV genotypes in the region.

METHODS

This study was conducted at a tertiary level hospital in Bijnor district of western Uttar Pradesh, India from January 2018 to January 2020. The duly filled case reporting forms and specimens of all the enrolled children were transported in cold chain to the referral laboratory at Christian Medical College (CMC), Vellore on a monthly basis for testing and storage of stool samples as well as data entry and analysis.

RESULTS

A total of 1055 under-5 children admitted with AGE, were enrolled. Proper stool specimens were collected from 932 children. Rotavirus was found positive in 368 (39.5%) stool specimens. Marked seasonality was observed in RV-positive cases with the highest incidence was noticed during winter months. The 0-11 mo age group had the highest incidence of RV-GE followed by 12-23 mo. G1 (42.08%) was the most frequent G-type whereas G1P[8] (26.23%) was the commonest circulating genotype.

CONCLUSION

The study confirms a significant burden of RV among AGE cases in young children in western Uttar Pradesh. The findings of the study may serve as useful baseline information to the Government of India for assessing vaccine performance after its introduction in the national immunization programmes.

Epidemiology and Genotype Distribution of Rotavirus Gastroenteritis in Under-Five Children of South Rajasthan, India

OBJECTIVE

To determine the epidemiology of rotavirus diarrhea and its genotypes distribution among under five children from Udaipur, Rajasthan.

METHODS

Hospital-based prospective study among children aged 0-59 mo of age hospitalized due to acute gastroenteritis and assess the clinical and epidemiological profile. Stool samples collected during 2017-2019 from 734 children, were tested by enzyme immune assay (EIA) to identify rotavirus and the samples that were positive were subjected to genotyping using published methods.

RESULTS

Rotavirus was detected in 12.94% (95/734) of the stool samples. Maximum positivity (38.9%) was seen in children aged 12-23 mo followed by 34.7% in 6-11 mo of age. Detection rates were higher (46.31%, 44/95) during winter months of December-February; 65% children with rotavirus diarrhea had severe dehydration followed by moderate dehydration in 32% of cases. G3P[8] (40, 43.01%) was the commonest genotype followed by G9P[4] (10, 10.75%).

CONCLUSION

Among under-five children hospitalized due to acute gastroenteritis in a tertiary care setting in Udaipur, Rajasthan, 12.9% of children were rotavirus positive with predominant (43.01%) circulation of G3P[8] strains.

Acute Gastroenteritis in Children Below 5 Years of Age at Tirupati, Andhra Pradesh, India Post Introduction of Rotavirus Vaccine into National Immunization Programme

OBJECTIVE

To identify the burden of rotavirus acute gastroenteritis (AGE) and the genotypes presenting in the authors' area in the period after introduction of rotavirus vaccine in Universal Immunization Programme (UIP).

METHODS

Children aged less than 5 y and presenting to hospital for the treatment of AGE were enrolled into the study from January 2016 to June 2019. Clinical details including age, gender, extent of illness, number of stools, concomitant vomiting and fever, grade of dehydration, and associated illness were recorded. Stool samples were tested for rotavirus using a commercially available ELISA Kit. Genotyping was performed for the rotavirus antigen-positive samples.

RESULTS

Rotavirus positive AGE was seen in 14.2% of the children. High burden of rotavirus gastroenteritis was seen in the age group of 6-23 mo and more cases were observed from December to February months. In our region the prevalent rotavirus genotypes in positive samples are G3 and G1 in G-typing, P[8] and P[4] in P-typing, respectively. G3P[8] and G1P[8] are the most prevalent genotypes identified in our area with a frequency of 35.1% and 25.9%, respectively. Almost all the cases (97.7%) got discharged and only one patient has died.

CONCLUSION

The findings conclude a declining trend in the rotavirus positive AGE cases in the authors' area after introduction of Rotavac vaccine in the UIP.

Rotavirus Gastroenteritis in Eastern Uttar Pradesh, India

OBJECTIVE

To identify cases of rotavirus diarrhea in Uttar Pradesh among children less than 5 y of age presenting with acute gastroenteritis, to study the clinical profile of the cases and to identify the rotavirus genotypes.

METHODS

Any child who is 0-59 mo of age who is admitted to the study facility with diarrhea as the presenting complaint were enrolled into the surveillance after obtaining informed consent. Clinical history and sociodemographic information was recorded for all the patients. Patients with dehydration were treated as per standard protocol. Stool samples were collected for isolation of rotavirus and identification of its genotype.

RESULTS

Of the 418 stool specimens collected, rotavirus was isolated in 47 (11.33%) samples. Rotavirus gastroenteritis was most common below the age of two years. A significant difference in the clinical characteristics between children who were positive for rotavirus and those who tested negative were not observed in this study. But patients with rotavirus diarrhea had longer duration of hospital stay (OR 3.31; CI 1.24-8.87). The outcome was similar in the two groups (OR 2.64; CI 0.27-25.89). G3P[8] was the most common type genotype isolated in 13 (28.89%) patients followed by G2P[4] in 7 (15.56%) patients. Thirteen patients (28.89%) had mixed genotype.

CONCLUSION

Rotavirus diarrhea was most common below two years of age. G3P[8] was the most common genotype identified.

Rotavirus Diarrhea and its Determinants Among Under-Five Children Admitted in a Tertiary Care Hospital of Southern Haryana, India

OBJECTIVE

To estimate the prevalence of rotavirus diarrhea and its demographic, social, and clinical characteristics among children less than five years of age admitted in a rural tertiary care institute.

METHODS

This prospective hospital-based observational study was carried out during February 2016 to June 2019. Diarrheal admissions of children aged 0-59 mo were screened and those who met the inclusion criteria were included in the study. Sociodemographic and clinical information was collected using a case report form. Stool samples were collected within 48 h of admission and transported in cold chain every month to the referral laboratory situated at Christian Medical College for testing.

RESULTS

Among the children admitted with acute diarrhea, 148 (11.02%) were positive for rotavirus in the study. As per Vesikari scoring system, around three fourth (76.2%) of children were having severe or very severe diarrhea. Severity of diarrhea was more among rotavirus positive cases as assessed by the Vesikari scoring system. The rotavirus diarrhea showed a peak during November to February.

CONCLUSION

Rotavirus diarrhea is an issue of public health importance, particularly due to its association with the severe diarrhea. As evidenced from similar settings in the world, rotavirus vaccine introduction and increased coverage is the most important strategy towards prevention and control of rotavirus diarrhea.

Clinical Profile, Risk-Factors, and Outcome of Rotaviral Diarrhea and Non-rotaviral Diarrhea Among Under-Five Children at Cuttack, Odisha, India

OBJECTIVE

To understand the prevalence of rotavirus diarrhea and its associated clinical and socio-demographic characteristics.

METHODS

The prospective hospital-based study was conducted at SVP Post Graduate Institute of Pediatrics and SCB Medical College, Odisha, India among children under-five years of age from April 2016 to July 2019. From all eligible children admitted at hospital, a case-report form containing information on clinical and socio-demographic characteristics was collected and an attempt was made to collect stool sample. A simple logistic regression method was used to assess factors associated with rotavirus diarrhea.

RESULTS

Of the 1963 children, median (IQR) age was 12 (8-19) mo with a female/male ratio was 1:2.05. The prevalence of rotavirus diarrhea was 36.4% (95% CI, 34.2%-38.6%). Children in the age group of 6-11 (OR 1.64, 95% CI, 1.24-2.18), 12-23 (OR 1.73, 95% CI, 1.31-2.29) mo had higher odds of getting rotavirus diarrhea, compared to those in that of 24-59 mo. The prevalence of wasting, stunting, underweight among children with rotavirus diarrhea was 25.2% (95% CI, 22%-28.4%), 2.1% (95% CI, 1.1%-3.1%), 9.0% (95% CI, 6.8%-11.2%), respectively.

CONCLUSION

The results of this study confirmed that diarrhea remains an important cause of hospitalization in children. Further studies are required in the community for Rotavirus and its genotyping.

Epidemiology of Acute Gastroenteritis Caused by Rotavirus among Children Less than Five Years Old Admitted in Hospital, in North India

OBJECTIVES

To report the data of burden of rotaviral acute gastroenteritis in under-five children from two states post-introduction of the vaccine.

METHODS

Children under 5 y of age hospitalized with diarrhea from the states of Haryana and Himachal Pradesh in north India were recruited in the study. Commercially available ELISA kits were used for testing rotavirus in the collected stool samples. Genotyping of the positive samples was done by reverse-transcription polymerase chain reaction.

RESULTS

Out of 345 samples collected, 69 (20%) were found to be positive for rotavirus by ELISA. Genotyping was done and G3P[8] (31.3%), G1P[8] (13.4%), G2P[4] (13.4%) were found to be prevalent strains. Mixed strains were also found in 19.4% stool samples.

CONCLUSIONS

The study highlighted the high burden of rotavirus associated diarrhea in north Indian states. The data is helpful for evaluating the impact of vaccine on the severity of acute gastroenteritis and the changing strains after the introduction of rotavirus vaccine in the Universal Immunization Program.

Rotavirus Gastroenteritis Hospitalizations Among Under-5 Children in Northern India

OBJECTIVE

To study epidemiological profile, prevalence, and molecular epidemiology of RVGE in hospitalized under-5 children at a tertiary care teaching rural hospital located in sub-Himalayan belt of Northern India.

METHODS

This was a hospital-based surveillance study done over 4 y (2016-2019) including under-5 children hospitalized with acute gastroenteritis (AGE). Demographic and clinical parameters were recorded in a pre-designed performa. After consent, stool samples were collected and sent to Christian Medical College (CMC), Vellore for RV screening by enzyme immunoassay (EIA). Each EIA-positive sample was further subjected to G and P typing using published methods.

RESULTS

Out of total 851 included children, rotavirus gastroenteritis (RVGE) was detected in 23.03% (196/851) cases by EIA. The highest incidence for RVGE-positive cases (40.43%) was observed in 2016 with gradual decline over next 3 y. Maximum cases of diarrhea were observed in 12-23 mo age group along with highest rotavirus detection. G3P[8] was most common genotype (46.94%) found, followed by G1P[8] (13.78%), G2P[4] (4.59%), G1P[6] (8.16%) and G9P[4] (3.57%). Mixed genotype was seen in 13.78% of total cases.

CONCLUSION

This study summarizes the changing trends in the epidemiology of RVGE in Northern India along with the major circulating genotypes postvaccine introduction.

Gastroenteritis in Haryana, India Post Introduction of Rotavirus Vaccine

OBJECTIVE

To evaluate the epidemiology of rotavirus gastroenteritis in Haryana post-introduction of rotavirus vaccine. Expanded National rotavirus surveillance network in India reported high burden of rotavirus diarrhea in India. The Government of India introduced the monovalent rotavirus vaccine made in India by Bharat Biotech in the national immunization programme from 2016 onward along with oral polio vaccine (OPV) and Pentavalent vaccines.

METHODS

A multi-centric, hospital-based surveillance study in the initial vaccine introducing states was started in a phased manner over a period of 3 y. PGIMS, Rohtak is a tertiary care center and was a part of the surveillance from 2016 to 2019. Children aged 0-59 mo admitted with acute gastroenteritis were enrolled into the surveillance and their stool samples were collected. Samples were tested at Christian Medical College (CMC), Vellore to detect rotavirus and reverse transcription-polymerase chain reaction (RT-PCR) was used for G and P typing.

RESULTS

A total of 904 children were enrolled in the present surveillance over a period of 3 y starting 1st July 2016 to 30th June 2019. Stool samples were collected and analyzed for 827 children and out of them 141 samples were positive for rotavirus (17.1%). Maximum rotavirus positivity was observed during the winter months. Rotavirus positivity percentage was observed maximum in 12-23 mo age group. A declining trend was observed in rotavirus positivity from 22.8% in 2016 to 14.5% in 2019. Most common strains of rotavirus isolated were G3P[8] followed by G1P[8].

CONCLUSION

This study highlights that epidemiology of acute gastroenteritis among children less than 5 y of age in Haryana postintroduction of rotavirus vaccination in the state and the decline in rotavirus positivity from 22.8% in 2016 to 14.5% in 2019.

The origins of G12P[6] rotavirus strains detected in Lebanon

The G12 rotaviruses are an increasingly important cause of severe diarrhoea in infants and young children worldwide. Seven human G12P[6] rotavirus strains were detected in stool samples from children hospitalized with gastroenteritis in Lebanon during a 2011-2013 surveillance study. Complete genomes of these strains were sequenced using VirCapSeq-VERT, a capture-based high-throughput viral-sequencing method, and further characterized based on phylogenetic analyses with global RVA and vaccine strains. Based on the complete genomic analysis, all Lebanese G12 strains were found to have Wa-like genetic backbone G12-P[6]-I1-R1-C1-M1-A1-N1-T1-E1-H1. Phylogenetically, these strains fell into two clusters where one of them might have emerged from Southeast Asian strains and the second one seems to have a mixed backbone between North American and Southeast Asian strains. Further analysis of these strains revealed high antigenic variability compared to available vaccine strains. To our knowledge, this is the first report on the complete genome-based characterization of G12P[6] emerging in Lebanon. Additional studies will provide important insights into the evolutionary dynamics of G12 rotaviruses spreading in Asia.

Epidemiology of rotavirus diarrhea among children less than 5 years hospitalized with acute gastroenteritis prior to rotavirus vaccine introduction in India

Background

Rotavirus is an important cause of severe diarrhea requiring hospitalization, accounting for approximately 78,000 deaths annually in Indian children below 5 years of age. We present epidemiological data on severe rotavirus disease collected during hospital-based surveillance in India before the introduction of the oral rotavirus vaccine into the national immunization schedule.

Methods

The National Rotavirus Surveillance Network was created involving 28 hospital sites and 11 laboratories across the four geographical regions of India. From September 2012 to August 2016 children less than 5 years of age hospitalized for diarrhea for at least 6 h, were enrolled. After recording clinical details, a stool sample was collected from each enrolled child, which was tested for rotavirus antigen using enzyme immunoassay (EIA). Nearly 2/3rd of EIA positive samples were genotyped using reverse transcription polymerase chain reaction to identify the G and P types.

Results

Of the 21,421 children enrolled during the 4 years surveillance, 36.3% were positive for rotavirus. The eastern region had the highest proportion of rotavirus associated diarrhea (39.8%), while the southern region had the lowest (33.8%). Rotavirus detection rates were the highest in children aged 6–23 months (41.8%), and 24.7% in children aged < 6 months. Although rotavirus associated diarrhea was seen throughout the year, the highest positivity was documented between December and February across all the regions. The most common rotavirus genotype was G1P[8] (52.9%), followed by G9P4 (8.7%) and G2P4 (8.4%).

Conclusions

There is high burden of rotavirus gastroenteritis among Indian children below 5 years of age hospitalized for acute diarrhea thereby highlighting the need for introduction of rotavirus vaccine into the national immunization program and also for monitoring circulating genotypes.

Diversity of rotavirus genotypes circulating in children < 5 years of age hospitalized for acute gastroenteritis in India from 2005 to 2016: analysis of temporal and regional genotype variation

Background

From 2016, the Government of India introduced the oral rotavirus vaccine into the national immunization schedule. Currently, two indigenously developed vaccines (ROTAVAC, Bharat Biotech; ROTASIIL, Serum Institute of India) are included in the Indian immunization program. We report the rotavirus disease burden and the diversity of rotavirus genotypes from 2005 to 2016 in a multi-centric surveillance study before the introduction of vaccines.

Methods

A total of 29,561 stool samples collected from 2005 to 2016 (7 sites during 2005–2009, 3 sites from 2009 to 2012, and 28 sites during 2012–2016) were included in the analysis. Stools were tested for rotavirus antigen using enzyme immunoassay (EIA). Genotyping was performed on 65.8% of the EIA positive samples using reverse transcription- polymerase chain reaction (RT-PCR) to identify the G (VP7) and P (VP4) types. Multinomial logistic regression was used to quantify the odds of detecting genotypes across the surveillance period and in particular age groups.

Results

Of the 29,561 samples tested, 10,959 (37.1%) were positive for rotavirus. There was a peak in rotavirus positivity during December to February across all sites. Of the 7215 genotyped samples, G1P[8] (38.7%) was the most common, followed by G2P[4] (12.3%), G9P[4] (5.8%), G12P[6] (4.2%), G9P[8] (4%), and G12P[8] (2.4%). Globally, G9P[4] and G12P[6] are less common genotypes, although these genotypes have been reported from India and few other countries. There was a variation in the geographic and temporal distribution of genotypes, and the emergence or re-emergence of new genotypes such as G3P[8] was seen. Over the surveillance period, there was a decline in the proportion of G2P[4], and an increase in the proportion of G9P[4]. A higher proportion of mixed and partially typed/untyped samples was also seen more in the age group 0–11 months.

Conclusions

This 11 years surveillance highlights the high burden of severe rotavirus gastroenteritis in Indian children < 5 years of age before inclusion of rotavirus vaccines in the national programme. Regional variations in rotavirus epidemiology were seen, including the emergence of G3P[8] in the latter part of the surveillance. Having pre-introduction data is important to track changing epidemiology of rotaviruses, particularly following vaccine introduction.

Climatic Parameters and Rotavirus Diarrhea Among Hospitalized Children: A Study of Eastern India

Background: Rotavirus diarrhea is often referred as "winter diarrheal disease" as it causes nearly 50% of the pediatric hospitalizations during winter season. This study was done with the objective of bringing out the epidemiological nexus of rotavirus cases with different seasonal parameters like maximum, minimum temperature, humidity, and average rainfall. Methods: This prospective observational study was conducted in a tertiary care teaching hospital of Eastern India from February 2016 to December 2018. Data on daily maximum and minimum temperature, relative humidity, and rainfall were collected. Result: Of 964 children admitted, 768 stool samples were collected for rotavirus assay. A total of 222 children (29%) were positive. The maximum, minimum temperature, average rainfall, and average humidity of 83.4 mm, 79.2%, 28.1, and 21.9, respectively, were significantly associated with positive rotaviral cases. Conclusions: The incidence of rotavirus positivity cases was found to be inversely associated with average temperature, humidity, and rainfall. The knowledge about the seasonal pattern in a particular geographical area would help in the reallocation of hospital services (staff and bed) to tackle the epidemic or emergency situations resulting from clustering of cases.

Burden and Molecular Epidemiology of Rotavirus Causing Diarrhea among Under-Five Children: A Hospital-based Study from Eastern India

Background

Rotavirus (RVA) causes severe gastroenteritis in under-five children, and there are many diverse strains of the virus that are localized to different parts of the world.

Objectives

To study the burden and molecular epidemiology of RVA causing gastroenteritis among children from Eastern India.

Materials and Methods

This hospital-based cross-sectional study included children under-five with gastroenteritis. Demographic and clinical parameters were recorded in a predesigned pro forma. Stool samples collected from these children were initially screened for RVA VP6 antigen by enzyme immunoassay (EIA). Each EIA-positive sample was then subjected to RNA extraction, followed by reverse transcription, and heminested multiplex polymerase chain reaction for genotyping of RVA strains.

Results

Of 320 included children, RVA was detected in 30.62% (98/320) cases by EIA. The highest incidence for RVA-positive cases (34.61%) was observed among children in the age group of 24-36 months, followed by 0-12 months (33.04%). Of the 97 completely typed samples, single genotype was detected in 85 (87.62%) samples with either G (VP7) or P (VP4) types. However, mixed genotypes were detected in 12 (11.21%) samples. G3P[8] (44.09%) was the most common genotype, followed by G1P[8] (32.65%), G2[P4] (5.10%), G1[P6] (3.06%), and G9[P4] (1.02%).

Conclusions

The present study found RVA positivity in 30.62% of children with gastroenteritis, with the highest burden among 24-36 months old. The predominant genotypes were G1, G3, and P[8]. Further large-scale/multicentric studies should be conducted to document the diversity of circulating RVA genotypes in this region for giving inputs for vaccination strategy.

Genetic characterization of group-A rotaviruses among children in eastern India during 2014-2016: Phylodynamics of co-circulating genotypes

BACKGROUND

Group-A human rotaviruses (GARV) are among the major cause of childhood diarrhea worldwide. In lieu of monitoring the circulatory GARV strains and underscoring the burden of GARV related hospitalization, a systematic surveillance was conducted in three hospitals of eastern India. In this hospital-based diarrheal disease surveillance (2014-2016), GARV was the most common cause of acute infantile gastroenteritis. The strains were genotyped and characterized to understand their prevalence and phylodynamics prior to the introduction of vaccine in eastern India.

MATERIALS AND METHODS

A total of 3652 stool samples were screened from children (≤5 years) hospitalized with acute diarrhea during 2014-2016. Initial screening for VP6 antigen was done by ELISA. GARV positive samples were genotyped by multiplex semi-nested PCR and DNA sequencing and phylogenetic analyses were based on the capsid proteins VP4 and VP7.

RESULTS

Of 3652 samples, 1817 (49.8%) were GARV positive. G1, G2, G3 and G9 in conjunction with P[4], P[6]and P[8]genotypes were seen to co-circulate in the population. A sharp deflection from G1 to G3 occurred since 2016; upsurge of G9 strains was seen in alternate years, whereas G2 strains had a low frequency. All the circulating genotypes depicted a low phylogenetic relatedness to the vaccine strains. Differences in antigenic epitopes of VP4 and VP7 proteins in local strains were seen when compared to the vaccine strains. A significant difference in the degree of dehydration, duration of mean hospital stay and frequency of vomiting/24 h between GARV positive and negative children was evident.

CONCLUSION

The study provides a relevant set of base-line data on high burden of rotaviral gastroenteritis and the varied genotypic diversity among children prior to the introduction of GARV vaccine in this endemic region. Continuous monitoring during post-vaccination era will be required to assess the impact of vaccination in this region.

Epidemiology and genetic diversity of group A rotavirus in acute diarrhea patients in pre-vaccination era in Himachal Pradesh, India

Acute gastroenteritis due to Group A rotaviruses remains the leading cause of mortality and morbidity in children in developing countries. India introduced its indigenous rotavirus vaccine Rotavac® in 2016 and Himachal Pradesh (HP) the first state to launch it. The present study aimed to evaluate rotavirus strain diversity associated with AGE prior to vaccine introduction in HP. A total of 331 fecal specimens collected from diarrheic children hospitalized at RPGMC Tanda, HP between July-2014 and June-2016 were screened for RVA by EIA. Rotavirus RNA was extracted by TRIZOL method and analyzed by RNA-PAGE. G/P typing was performed using semi-nested multiplex reverse transcriptase PCR. Rotavirus was detected in 45% (n = 149/331) of diarrheic children, with highest rate observed in the 6-11 months age group (47%). Vomiting was found more frequently associated with RV-infection. Among G-types, G12 was found most prevalent (33.1%) followed by G1 (28.4%), G9 (12.2%), G2 (9.5%), G3 (3.4%) and G10 (2.7%). G4 (0.7%) strains were rarely detected. Among P-types, P[6] was the most prevalent (40.5%) followed by P[8] (29.1%) and P[4] (14.2%). Of note, genotypes G3 and P[11] were detected for the first time in HP. Among G/P combinations, G12P[6] was most prevalent (30.4%) followed by G1P[8] (20.3%), G2P[4] (4.7%), G1P[6] (3.4%) and G3P[8] (2.7%). Interestingly, our study observed high percentage of unusual strains (14.2%) namely G9P[4], G2P[6], G2P[8], G12P[4] and G1P[11]. The regionally common strains G3P[6], G4P[6], G9P[6], G9P[8], G10P[6], G10P[8] and G12P[8] strains were very rarely detected. Of interest, RNA migration pattern of G1P[8] was DS-1 like and genomic heterogeneity was observed within G12P[4] strains with both long and short electropherotypes. Our study highlights rich genetic diversity with emergence of rare rotavirus strains circulating in HP and provides baseline data prior to Rotavac® introduction that will help to gauge the impact of the Rotavac® vaccine in HP.

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.

Rotavirus vaccine impact assessment surveillance in India: protocol and methods

INTRODUCTION

Rotavirus infection accounts for 39% of under-five diarrhoeal deaths globally and 22% of these deaths occur in India. Introduction of rotavirus vaccine in a national immunisation programme is considered to be the most effective intervention in preventing severe rotavirus disease. In 2016, India introduced an indigenous rotavirus vaccine (Rotavac) into the Universal Immunisation Programme in a phased manner. This paper describes the protocol for surveillance to monitor the performance of rotavirus vaccine following its introduction into the routine childhood immunisation programme.

METHODS

An active surveillance system was established to identify acute gastroenteritis cases among children less than 5 years of age. For all children enrolled at sentinel sites, case reporting forms are completed and a copy of vaccination record and a stool specimen obtained. The forms and specimens are sent to the referral laboratory for data entry, analysis, testing and storage. Data from sentinel sites in states that have introduced rotavirus vaccine into their routine immunisation schedule will be used to determine rotavirus vaccine impact and effectiveness.

ETHICS AND DISSEMINATION

The Institutional Review Board of Christian Medical College, Vellore, and all the site institutional ethics committees approved the project. Results will be disseminated in peer-reviewed journals and with stakeholders of the universal immunisation programme in India.

Evaluation of different genomic regions of Rotavirus A for development of real time PCR

The nucleotide alignment of all 11 genes of human Rotavirus A (RVA) strains revealed suitability of NSP2, NSP3 and VP6 genes for the development of real time PCR (qRT-PCR). Evaluation of qRT-PCR assays using known rotavirus ELISA positive and negative fecal specimens showed non-overlapping ranges of Mean ±3SD cycle threshold (Ct) values for NSP3 and VP6 based assays. Using serial dilutions of purified RVA, high sensitivity of VP6 qRT-PCR assay (1.95 × 10^-5 pg/μL of RNA) was recorded as compared to NSP2 and NSP3 qRT-PCR assays (1.95 × 10^-4 pg/μL of RNA). Further, evaluation of the VP6 qRT-PCR assay involving 266 fecal specimens and frequency polygon analysis of the data indicated cut-off value of 35 for Ct with high sensitivity (126/131, 96%) and specificity (12/12, 100%). This VP6 qRT-PCR assay will be a useful diagnostic tool to evaluate clinical presentations in rotaviral gastroenteritis under different conditions such as breast feeding and administration of rotavirus vaccines.

Rotavirus gastroenteritis in Indian children < 5 years hospitalized for diarrhoea, 2012 to 2016

Background

In 2016, the Government of India introduced the oral rotavirus vaccine (ROTAVAC, Bharat Biotech, India) in 4 states of India as part of the Universal Immunization Programme, and expanded to 5 more states in 2017. We report four years of data on rotavirus gastroenteritis in hospitalized children < 5 years of age prior to vaccine introduction.

Methods

Children from 7 sites in southern and northern India hospitalized for diarrhoea were recruited between July 2012 and June 2016. Stool samples were screened for rotavirus using enzyme immunoassay (EIA). The EIA positive samples were genotyped by reverse-transcription polymerase chain reaction.

Results

Of the 5834 samples from the 7 sites, 2069 (35.5%) were positive for rotavirus by EIA. Genotyping was performed for 2010 (97.1%) samples. G1P[8](56.3%), G2P[4](9.1%), G9P[4](7.6%), G9P[8](4.2%), and G12P[6](3.7%) were the common genotypes in southern India and G1P[8](36%), G9P[4](11.4%), G2P[4](11.2%), G12P[6](8.4%), and G3P[8](5.9%) in northern India.

Conclusions

The study highlights the high prevalence of rotavirus gastroenteritis in India and the diversity of rotavirus genotypes across different geographical regions. Pre- vaccine surveillance data is necessary to evaluate the potential change in admission rates for gastroenteritis and circulating rotavirus genotypes after vaccine introduction, thus assessing impact.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-6406-0) contains supplementary material, which is available to authorized users.

Upsurge and spread of G3 rotaviruses in Eastern India (2014-2016): Full genome analyses reveals heterogeneity within Wa-like genomic constellation

Advent of new strains and shift in predominantly circulating genotypes are characteristics of group- A rotavirus (RVA), one of the major causes of childhood gastroenteritis. During diarrheal disease surveillance at Kolkata, India (2014-2016), a shift in circulating RVA strains from G1P[8] to G3P[8] was seen. Stool samples from children (n = 3048) with acute gastroenteritis were tested of which 38.7% were RVA positive. G1 was the predominant strain (65.3%) in 2014-2015 whereas in late 2015 and 2016, G3 became the preponderant strain (44.6%). In the past decade G3 strains were not observed in this region, we conducted whole genome sequencing of representative strains to gain insight into the phenomenon of emergence and genetic constellation of these circulating human G3 strains. The analyses revealed intergenogroup reassortment in G3P[4] strains (among Wa and DS-1-like genogroup) whereas G3P[8] strains were authentic Wa-like. Phylogenetic analysis revealed Kolkata G3 strains as polymorphic and thus they formed two sub-clusters due to antigenic differences in their VP7 protein. One of the sub-clusters had the wild-type threonine at 87 amino acid position while another sub-cluster had an isoleucine mutation. Presence of additional N-linked glycosylation site at amino acid 283 of VP7 glycoprotein suggests that the major neutralizing epitope on the VP7 (G3) of RotaTeq vaccine differs from the currently circulating G3 strains. The study is important as efficiency of rotavirus vaccine depends on the circulating heterogeneous genotype constellations. Continuous monitoring of circulating RVA strains in endemic settings like India is therefore important in pre- and post-vaccination period to monitor the emergence of new reassortant genotypes in addition to assessing vaccine efficacy.

Molecular epidemiology of rotaviruses in the south-east Asian region from 2009 to 2015

BACKGROUND

In Asia, rotavirus accounts for approximately 45% of admissions due to acute gastroenteritis in children <5 years, and causes about 145,000 deaths every year. We studied the distribution of rotavirus strains from Myanmar, Sri Lanka, and Nepal during 2009-2015.

METHODS

Stool samples collected from children <5 years of age hospitalized with acute diarrhea in the three sites and positive for rotavirus antigen by enzyme immunoassay (EIA) were sent to the Christian Medical College, Vellore from 2009 to 2015. G and P typing of rotavirus strains were performed using reverse-transcription polymerase chain reaction (RT-PCR).

RESULT

Of the 2354 EIA positive samples tested, G12P[8] (36.8%), G1P[8] (30.1%), and G12P[6] (41.3%) were the most common strains isolated from Myanmar, Sri Lanka, and Nepal respectively.

CONCLUSION

There was substantial diversity of rotavirus genotypes, and continued surveillance in developing countries of Asia will help in understanding the epidemiology of rotavirus before and after introduction of vaccines.

Genetic analysis of rotavirus G2P[4] strains in Pune, Western India: circulation of a novel reassortant bearing E6 NSP4 genotype

In India, G2P[4] strains are known to be the second most predominant group A rotaviruses causing acute gastroenteritis among children. This study was performed to determine the diversity within VP7(G), VP4(P), VP6(I) and NSP4(E) genes of 16 G2P[4] rotavirus strains detected in children hospitalized for acute gastroenteritis in Pune, Western India during 2009-2013. Fourteen strains showed G2-P[4]-I2-E2 and two strains showed G2-P[4]-I2-E6 genotype constellation. Phylogenetic analysis showed their clustering into G2-IV-a3, P[4]-5bi/ii, I2-3ii and E2-4i/ii or E6 genotypes/lineages. These data reveal inter- and/or intra-genotypic variations in a genogroup-2 constellation of G2P[4] rotavirus strains circulating in Pune, Western India, providing evidence of a novel G2P[4] reassortant bearing a rare NSP4 genotype, E6 during 2009-2013.

Differences of Rotavirus Vaccine Effectiveness by Country: Likely Causes and Contributing Factors

Rotaviruses are a major cause of acute gastroenteritis in infants and young children worldwide and in many other mammalian and avian host species. Since 2006, two live-attenuated rotavirus vaccines, Rotarix^® and RotaTeq^®, have been licensed in >100 countries and are applied as part of extended program of vaccination (EPI) schemes of childhood vaccinations. Whereas the vaccines have been highly effective in high-income countries, they were shown to be considerably less potent in low- and middle-income countries. Rotavirus-associated disease was still the cause of death in >200,000 children of <5 years of age worldwide in 2013, and the mortality is concentrated in countries of sub-Saharan Africa and S.E. Asia. Various factors that have been identified or suggested as being involved in the differences of rotavirus vaccine effectiveness are reviewed here. Recognition of these factors will help to achieve gradual worldwide improvement of rotavirus vaccine effectiveness.

Epidemiology and genetic diversity of human parechoviruses circulating among children hospitalised with acute gastroenteritis in Pune, Western India: a 5-years study

Human parechoviruses (HPeVs) are known to cause various clinical manifestations including acute gastroenteritis. Although HPeV infections and their genotypes have been detected in human patients worldwide, no such reports are available from India to ascertain the association of HPeVs in acute gastroenteritis. The present study was conducted to determine the clinical features and genetic diversity of HPeVs detected in children hospitalised for acute gastroenteritis. Stool specimens (n= 979) collected from children aged ⩽5 years hospitalised for acute gastroenteritis in Pune, western India during January 2006–December 2010 were included. HPeV RNA was detected by reverse transcription-polymerase chain reaction (RT-PCR) (5′UTR) followed by genotyping using VP1 gene-based PCR and phylogenetic analysis. HPeV was detected in 13·9% (136/979) of the cases, co-infections with other enteric viruses were found in 43·4%. HPeV was more frequent in children ⩽1 year age with infections reported throughout the year. A total of 102/136 (75%) HPeV strains were genotyped, which comprised 13 different HPeV genotypes. Of these, HPeV1 was the most predominant genotype detected and phylogenetically clustered with the Harris strain which is rarely reported. The study documents circulation of heterogeneous HPeV genotypes. Two variant strains of HPeV4 and ‘RGD absent’ HPeV5 and 6 strains were also detected. This is the first report of HPeV with diversified genotypes identified in acute gastroenteritis patients from India.

Genotype distribution of Group A rotavirus from southern India, 2005-2016

Diarrheal disease due to Group A rotaviruses remain a leading cause of mortality and morbidity in the less developed parts of the world. India has started a phased roll out of rotavirus vaccine in the national immunization program. This analysis summarizes the rotavirus genotype strain distribution pre-vaccine introduction in Vellore, India from December 2005 to June 2016. Rotavirus was responsible for 32% of all diarrheal admission to the hospital. G2P[4] was the predominant strain in the initial years and was gradually replaced by G1P[8]. The emergence of G9P[4] replacing G9P[8], and the detection of G12 strains over several years were documented. There was no clear seasonality of disease. These data form the baseline to monitor genotype distribution post-vaccine introduction in Tamil Nadu.

Complex reassortment events of unusual G9P[4] rotavirus strains in India between 2011 and 2013

Rotavirus A (RVA) is the predominant etiological agent of acute gastroenteritis in young children worldwide. Recently, unusual G9P[4] rotavirus strains emerged with high prevalence in many countries. Such intergenogroup reassortant strains highlight the ongoing spread of unusual rotavirus strains throughout Asia. This study was undertaken to determine the whole genome of eleven unusual G9P[4] strains detected in India during 2011-2013, and to compare them with other human and animal global RVAs to understand the exact origin of unusual G9P[4] circulating in India and other countries worldwide. Of these 11 RVAs, four G9P[4] strains were double-reassortants with the G9-VP7 and E6-NSP4 genes on a DS-1-like genetic backbone (G9-P[4]-I2-R2-C2-M2-A2-N2-T2-E6-H2). The other strains showed a complex genetic constellation, likely derived from triple reassortment event with the G9-VP7, N1-NSP2 and E6-NSP4 on a DS-1-like genetic backbone (G9-P[4]-I2-R2-C2-M2-A2-N1-T2-E6-H2). Presumably, these unusual G9P[4] strains were generated after several reassortment events between the contemporary co-circulating human rotavirus strains. Moreover, the point mutation S291L at the interaction site between inner and outer capsid proteins of VP6 gene may be important in the rapid spread of this unusual strain. The complex reassortment events within the G9[4] strains may be related to the high prevalence of mixed infections in India as reported in this study and other previous studies.

Prevalence and characterization of rotaviruses in children hospitalized for diarrheal disease in a tertiary care hospital, Pune

BACKGROUND

Diarrhoea remains the second most common cause of death among children below 5 years globally. Among various enteric pathogens, rotavirus appears to be the most important aetiological agent of acute gastroenteritis in infants and young children. Increased understanding of epidemiology of rotavirus infections is needed to improve the vaccine efficacy.

AIM

This study aims to determine prevalence rotavirus infection and prevalent circulating strains of rotavirus in and around Pune.

SETTING AND DESIGN

Prospective hospital-based study. The study was approved by Institutional Ethical Committee.

MATERIALS AND METHODS

Stool samples (n = 100) were collected from children aged <5 years, hospitalised for acute diarrhoea in paediatric ward at a tertiary care hospital. Samples were subjected for rotavirus antigen capture ELISA. The viral RNA was subjected to multiplex reverse transcription polymerase chain reaction to amplify VP7 genotypes G1-G4, G8-G10 and G12 and VP4 genotypes P[4], P[6], P[8], P[9], P[10] and P[11]. Nontypable rotavirus strains were sequenced.

RESULTS

About 35% stool samples were positive for rotavirus antigen by ELISA. G9P[4] (28.6%) was found to be the most prevalent rotavirus strain. The detection of emerging strain G12P[6] (14.3%) and rare reassortant strain G9P[4] was the significant finding.

CONCLUSION

Genotypes found in circulation are not present in the currently used vaccine. Thus, an emergence of newer genotypes over a period calls for the continued surveillance and genomic characterisation of rotaviruses to improve the vaccine efficacy.

Human rotavirus strains circulating in Venezuela after vaccine introduction: predominance of G2P[4] and reemergence of G1P[8]

BACKGROUND

Rotavirus (RV) is the most common cause of severe childhood diarrhea worldwide. Despite Venezuela was among the first developing countries to introduce RV vaccines into their national immunization schedules, RV is still contributing to the burden of diarrhea. Concerns exist about the selective pressure that RV vaccines could exert on the predominant types and/or emergence of new strains.

RESULTS

To assess the impact of RV vaccines on the genotype distribution 1 year after the vaccination was implemented, a total of 912 fecal specimens, collected from children with acute gastroenteritis in Caracas from February 2007 to April 2008, were screened, of which 169 (18.5%) were confirmed to be RV positive by PAGE. Rotavirus-associated diarrhea occurred all year-round, although prevailed during the coolest and driest months among unvaccinated children under 24 months old. Of 165 RV strains genotyped for G (VP7) and P (VP4) by seminested multiplex RT-PCR, 77 (46.7%) were G2P[4] and 63 (38.2%) G1P[8]. G9P[8], G3P[8] and G2P[6] were found in a lower proportion (7.3%). Remarkable was also the detection of <5% of uncommon combinations (G8P[14], G8P[4], G1P[4] and G4P[4]) and 3.6% of mixed infections. A changing pattern of G/P-type distribution was observed during the season studied, with complete predominance of G2P[4] from February to June 2007 followed by its gradual decline and the reemergence of G1P[8], predominant since January 2008. Phylogenetic analysis of VP7 and VP4 genes revealed a high similarity among G2P[4] and global strains belonging to G2-II and P[4]-V lineages. The amino acid substitution 96D → N, related with reemergence of the G2 genotype elsewhere, was observed. The G1P[8] strains from Caracas were grouped into the lineages G1-I and P[8]-III, along with geographically remote G1P[8] rotaviruses, but they were rather distant from Rotarix® vaccine and pre-vaccine strains. Unique amino acid substitutions observed on neutralization domains of the VP7 sequence from Venezuelan post-vaccine G1P[8] could have conditioned their re-emergence and a more efficient dissemination into susceptible population.

CONCLUSIONS

The results suggest that natural fluctuations of genotypes in combination with forces driving the genetic evolution could determine the spread of novel strains, whose long-term effect on the efficacy of available vaccines should be determined.