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

The 2nd China Vaccinology Integrated Innovation & Teaching Development Conference: Promoting the construction of vaccinology discipline system

The 2nd China Vaccinology Integrated Innovation & Teaching Development Conference was held in Sun Yat-sen University, Shenzhen, 18-19, November 2023. Over 200 participants in the field of Vaccinology gathered together to address challenges and issues relevant to vaccine education and training courses, research, and public health programs in China. The conference themed "Promoting the Integrated and Innovative Development of Vaccinology through Collective Efforts." The conference was organized by the China Association of Vaccine (CAV) and hosted by Vaccinology Education Professional Committee of CAV, and School of Public Health (Shenzhen), Sun Yat-sen University. Other partners included the Medical Virology Branch of the Chinese Medical Association, the editorial committee of the Chinese Journal of Preventive Medicine, Human Vaccines & Immunotherapeutics, and the People's Medical Publishing House. The 1st conference was held in Hangzhou, in October 2020.

Frequency and genotyping of group A rotavirus among Egyptian children with acute gastroenteritis: a hospital-based cross-sectional study

BACKGROUND

This hospital-based cross-sectional study aims to investigate the epidemiologic and clinical characteristics of rotavirus group A (RVA) infection among children with acute gastroenteritis and to detect the most common G and P genotypes in Egypt.

METHODS

A total of 92 stool samples were collected from children under five who were diagnosed with acute gastroenteritis. RVA in stool samples was identified using ELISA and nested RT-PCR. Common G and P genotypes were identified utilizing multiplex nested RT-PCR assays.

RESULTS

RVA was detected at a rate of 24% (22 /92) using ELISA and 26.1% (24 /92) using VP6 nested RT-PCR. The ELISA test demonstrated diagnostic sensitivity, specificity, and accuracy of 91.7%, 100%, and 97.8%, respectively. G3 was the most prevalent G type (37.5%), followed by G1 (12.5%), whereas the most commonly detected P type were P[8] (41.7%) and P[6] (8.2%). RVA-positive samples were significantly associated with younger aged children (p = 0.026), and bottle-fed (p = 0.033) children. In addition, RVA-positive samples were more common during cooler seasons (p = 0.0001). Children with rotaviral gastroenteritis had significantly more frequent episodes of diarrhea (10.87 ± 3.63 times/day) and vomiting (8.79 ± 3.57 times/day) per day (p = 0.013 and p = 0.011, respectively). Moreover, they had a more severe Vesikari clinical score (p = 0.049).

CONCLUSION

RVA is a prevalent cause of acute gastroenteritis among Egyptian children in our locality. The discovery of various RVA genotypes in the local population, as well as the identification of common G and P untypeable strains, highlights the significance of implementing the rotavirus vaccine in Egyptian national immunization programs accompanied by continuous monitoring of strains.

Driving forces of continuing evolution of rotaviruses

Rotaviruses are non-enveloped double-stranded RNA virus that causes acute diarrheal diseases in children (< 5 years). More than 90% of the global rotavirus infection in humans was caused by Rotavirus group A. Rotavirus infection has caused more than 200000 deaths annually and predominantly occurs in the low-income countries. Rotavirus evolution is indicated by the strain dynamics or the emergence of the unprecedented strain. The major factors that drive the rotavirus evolution include the genetic shift that is caused by the reassortment mechanism, either in the intra- or the inter-genogroup. However, other factors are also known to have an impact on rotavirus evolution. This review discusses the structure and types, epidemiology, and evolution of rotaviruses. This article also reviews other supplemental factors of rotavirus evolution, such as genetic reassortment, mutation rate, glycan specificity, vaccine introduction, the host immune responses, and antiviral drugs.

Prevalence and genetic diversity of rotavirus in Bangladesh during pre-vaccination period, 1973-2023: a meta-analysis

Introduction

Rotavirus infection is a major cause of mortality among children under 5 years in Bangladesh. There is lack of integrated studies on rotavirus prevalence and genetic diversity during 1973 to 2023 in Bangladesh.

Methods

This meta-analysis was conducted to determine the prevalence, genotypic diversity and seasonal distribution of rotavirus during pre-vaccination period in Bangladesh. This study included published articles on rotavirus A, rotavirus B and rotavirus C. We used Medline, Scopus and Google Scholar for published articles. Selected literatures were published between 1973 to 2023.

Results

This study detected 12431 research articles published on rotavirus. Based on the inclusion criteria, 29 of 75 (30.2%) studies were selected. Molecular epidemiological data was taken from 29 articles, prevalence data from 29 articles, and clinical symptoms from 19 articles. The pooled prevalence of rotavirus was 30.1% (95% CI: 22%-45%, p = 0.005). Rotavirus G1 (27.1%, 2228 of 8219) was the most prevalent followed by G2 (21.09%, 1733 of 8219), G4 (11.58%, 952 of 8219), G9 (9.37%, 770 of 8219), G12 (8.48%, 697 of 8219), and G3 (2.79%, 229 of 8219), respectively. Genotype P[8] (40.6%, 2548 of 6274) was the most prevalent followed by P[4] (12.4%, 777 of 6274) and P[6] (6.4%, 400 of 6274), respectively. Rotavirus G1P[8] (19%) was the most frequent followed by G2P [4] (9.4%), G12P[8] (7.2%), and G9P[8], respectively. Rotavirus infection had higher odds of occurrence during December and February (aOR: 2.86, 95% CI: 2.43-3.6, p = 0.001).

Discussion

This is the first meta-analysis including all the studies on prevalence, molecular epidemiology, and genetic diversity of rotavirus from 1973 to 2023, pre-vaccination period in Bangladesh. This study will provide overall scenario of rotavirus genetic diversity and seasonality during pre-vaccination period and aids in policy making for rotavirus vaccination program in Bangladesh. This work will add valuable knowledge for vaccination against rotavirus and compare the data after starting vaccination in Bangladesh.

Human rotavirus strains circulating among children in the capital of China (2018-2022)_ predominance of G9P[8] and emergence ofG8P[8]

OBJECTIVE

This study aimed to update the genetic diversity of Rotavirus (RV) infections in children under five years old in Beijing, China.

METHODS

A 5-year active hospital-based surveillance for sporadic acute gastroenteritis (AGE) from January 2018 to December 2022 in the capital of China was performed. A total of 748 fecal samples from AGE patients were collected for followed by RV antigen detection by ELSIA, RNA detection by reverse transcription PCR, G/P genotyping and phylogenetic analyzing.

RESULTS

RV antigen was detected in 11.0% of the collected samples, with 54 samples confirmed to be RV RNA positive. G9 and G8 genotypes were identified in 43 (79.6%) and 7 (13.0%) samples, respectively, all of which were allocated to P[8]. The predominant G/P combination was G9P[8] (79.6%), following by G8P[8] (13.0%), G4P[8] (5.6%) and G3P[8] (1.9%). A significant change in G/P-type distribution was observed, with the G9P[8] being predominant from 2018 to 2021, followed by the emergence of an uncommon G8P[8] genotype, which was first reported in 2021 and became predominant in 2022. Blast analysis showed that one G1 isolate had a high similarity of 99.66% on nucleotide acid with RotaTeq vaccine strain with only one amino acid difference L150V. Additionally, one P[8] isolate was clustered into a branch together with RotaTeq vaccine strain G6P[8].

CONCLUSIONS

The study reveals that G8P[8] has become the predominant genotype in pediatric outpatients in China for the first time, indicating a significant change in the composition of RV genetic diversity. The importance of RVA genotyping in surveillance is emphasized, as it provides the basis for new vaccine application and future vaccine efficacy evaluation.

Reassortment and genomic analysis of a G9P[8]-E2 rotavirus isolated in China

OBJECTIVE

To isolate a prevalent G9P[8] group A rotavirus (RVA) (N4006) in China and investigate its genomic and evolutionary characteristics, with the goal of facilitating the development of a new rotavirus vaccine.

METHODS

The RVA G9P[8] genotype from a diarrhea sample was passaged in MA104 cells. The virus was evaluated by TEM, polyacrylamide gel electrophoresis, and indirect immunofluorescence assay. The complete genome of virus was obtained by RT-PCR and sequencing. The genomic and evolutionary characteristics of the virus were evaluated by nucleic acid sequence analysis with MEGA ver. 5.0.5 and DNASTAR software. The neutralizing epitopes of VP7 and VP4 (VP5* and VP8*) were analyzed using BioEdit ver. 7.0.9.0 and PyMOL ver. 2.5.2.

RESULTS

The RVA N4006 (G9P[8] genotype) was adapted in MA104 cells with a high titer (105.5 PFU/mL). Whole-genome sequence analysis showed N4006 to be a reassortant rotavirus of Wa-like G9P[8] RVA and the NSP4 gene of DS-1-like G2P[4] RVA, with the genotype constellation G9-P[8]-I1-R1-C1-M1-A1-N1-T1-E2-H1 (G9P[8]-E2). Phylogenetic analysis indicated that N4006 had a common ancestor with Japanese G9P[8]-E2 rotavirus. Neutralizing epitope analysis showed that VP7, VP5*, and VP8* of N4006 had low homology with vaccine viruses of the same genotype and marked differences with vaccine viruses of other genotypes.

CONCLUSION

The RVA G9P[8] genotype with the G9-P[8]-I1-R1-C1-M1-A1-N1-T1-E2-H1 (G9P[8]-E2) constellation predominates in China and may originate from reassortment between Japanese G9P[8] with Japanese DS-1-like G2P[4] rotaviruses. The antigenic variation of N4006 with the vaccine virus necessitates an evaluation of the effect of the rotavirus vaccine on G9P[8]-E2 genotype rotavirus.

Public health impact and cost-effectiveness of rotavirus vaccination in China: Comparison between private market provision and national immunization programs

In China, progress to include the RV vaccine in the national immunization program (NIP) is slow. The only two vaccines, the Lanzhou lamb rotavirus vaccine (LLR) and Rotateq, are provided through the private market. This study aims to assess the health impact and cost-effectiveness of using three vaccines in the NIP, Rotateq, Rotarix, and LLR, compared to the status quo. A decision-tree Markov model was adopted to follow the 2019 birth cohort, and a societal perspective was used. Input parameters were based on the latest local data when possible. Outcomes included cases and deaths averted, quality-adjusted life years (QALYs) gained, and incremental cost-effectiveness ratios (ICER). Sensitivity analyses and scenario analyses to consider herd immunity and vaccine price reduction were performed. Including Rotateq in the NIP was projected to prevent 348 million RVGE cases (62.6% reduction) and 4251 deaths (72.6% reduction) compared to the status quo. Rotarix through the NIP would prevent 48.7% of cases and 63.2% of deaths, and LLR would avert 20.3% of cases and 22.4% of deaths. The ICERs per QALY gained were US$ 8833 for Rotateq through the NIP, US$ 9503 for Rotarix, and US$ 26,759 for LLR. In uncertainty analyses, the reduction of vaccine prices and the incorporation of herd immunity further improved the cost-effectiveness of the NIPs, especially Rotateq or Rotarix. In conclusion, introducing the RV vaccine in China's NIP is expected to be cost-effective compared to the GDP per capita. Reducing vaccine prices and adopting vaccines with better efficacy would be the future focus.

The imported infections among foreign travelers in China: an observational study

BACKGROUND

In the past few decades, globalization has rendered more frequent and intensive population movement between countries, which has changed the original disease spectrum and brought a huge health impact on the global population including China. This study aims to describe the spectrum and epidemiological characteristics of imported infections among foreign travelers travelling to China.

METHODS

The data on imported infections among foreign travelers were obtained from Custom Inbound Screening System (CISS) and the National Notifiable Infectious Disease Reporting System (NNIDRS). All the infections were classified into respiratory, gastrointestinal, vector-borne, blood/sex-transmitted and mucocutaneous diseases, of which case numbers and incidences were calculated and the proportions were compared among subgroups.

RESULTS

In total, 17,189 travelers diagnosed with 58 imported infectious diseases were reported from 2014 to 2018, with an overall incidence of 122.59 per million. Respiratory infection (7,351 cases, mainly influenza) and blood/sex-transmitted diseases (6,114 cases mainly Hepatitis B and HIV infection) were the most frequently diagnosed diseases, followed by vector-borne infections (3,128 cases, mainly dengue fever and malaria). The highest case number was from Asia and Europe, while the highest incidence rate was from Africa (296.00 per million). When specific diagnosis was compared, both the highest absolute case number and incidence were observed for influenza. An obvious seasonal pattern was observed for vector-borne diseases, with the annual epidemic spanning from July to November. The origin-destination matrices disclosed the movement of imported infection followed specific routes.

CONCLUSIONS

Our study provided a profile of infectious diseases among foreign travelers travelling to China and pinpointed the target regions, seasons and populations for prevention and control, to attain an informed control of imported infections in China.

Genomic and evolutionary characteristics of G9P[8], the dominant group a rotavirus in China (2016–2018)

G9P[8] became the predominant rotavirus A (RVA) genotype in China in 2012. To evaluate its genetic composition at the whole-genome level, 115 G9P[8] RVA strains isolated from children under 5 years old were sequenced and characterized. All 13 strains in 2016 and 2017 and an additional 54 strains in 2018 were genotyped as G9-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1. The other 48 strains in 2018 were all genotyped as G9-P[8]-I1-R1-C1-M1-A1-N1-T1-E2-H1, with the NSP4 gene characterized as a DS-1-like genotype. The time of the most recent common ancestor (tMRCA) and evolution rates of the VP7, VP4, and NSP4 (E1 and E2) genes of these strains were estimated by Bayesian evolutionary dynamics analysis. We estimated the evolution rates (nt substitutions per site per year) as 1.38 × 10^–3 [the 95% highest posterior density (HPD) was 1.09–1.72 × 10^–3] for VP7, 0.87 × 10^–3 (95% HPD: 0.75–1.00 × 10^–3) for VP4, 0.56 × 10^–3 (95% HPD: 0.41–0.73 × 10^–3) for NSP4-E1, and 1.35 × 10^–3 (95% HPD: 0.92–1.86 × 10^–3) for NSP4-E2. The tMRCA was estimated to be 1935.4 (95% HPD: 1892.4–1961.3) for VP7, 1894.3 (95% HPD: 1850.5–1937.8) for VP4, 1929.4 (95% HPD: 1892.4–1961.3) for NSP4-E1, and 1969.2 (95% HPD: 1942.2–1985.3) for NSP4-E2. The baseline genetic information in this study is expected to improve our understanding of the genomic and evolutionary characteristics of the rotavirus genome. Furthermore, it will provide a basis for the development of next-generation rotavirus vaccines for humans.

Rotavirus and Norovirus Infections in Children Under 5 Years Old with Acute Gastroenteritis in Southwestern China, 2018-2020

OBJECTIVE

Rotaviruses and noroviruses are important causes of acute gastroenteritis in children. While previous studies in China have mainly focused on rotavirus, we investigated the incidence of norovirus in addition to rotavirus in Southwestern China.

METHODS

From January 2018 to December 2020, cases of rotavirus or norovirus infections among children under five ages with acute gastroenteritis were evaluated retrospectively.

RESULTS

The detection rate of rotavirus was 24.5% (27,237/111,070) and norovirus was 26.1% (4649/17,797). Among 17,113 cases submitted for dual testing of both rotavirus and norovirus, mixed rotavirus/norovirus infections were detected in 5.0% (859/17,113) of cases. While there was no difference in norovirus incidence in outpatient compared to hospitalized cases, rotavirus was detected two times more in outpatients compared to hospitalized cases (26.6% vs.13.6%; P < 0.001). Both rotavirus and norovirus infections peaked in children aged 12-18 months seeking medical care with acute gastroenteritis (35.6% rotavirus cases; 8439/23,728 and 32.5% norovirus cases; 1660/5107). Rotavirus infections were frequent between December and March of each year while norovirus was detected earlier from October to December. Our results showed significant correlation between virus detection and environmental factors such as average monthly temperature but not relative humidity. In addition, we observed a reduction in the detection rates of rotavirus and norovirus at the beginning of the SARS-CoV-2 pandemic in 2020.

CONCLUSION

Our results indicate that rotavirus and norovirus are still important viral agents in pediatric acute gastroenteritis in Southwestern China.

Genetic characterization of two G8P[8] rotavirus strains isolated in Guangzhou, China, in 2020/21: evidence of genome reassortment

Background

The G8 rotavirus genotype has been detected frequently in children in many countries and even became the predominant strain in sub-Saharan African countries, while there are currently no reports from China. In this study we described the genetic characteristics and evolutionary relationship between rotavirus strains from Guangzhou in China and the epidemic rotavirus strains derived from GenBank, 2020–2021.

Methods

Virus isolation and subsequent next-generation sequencing were performed for confirmed G8P[8] specimens. The genetic characteristics and evolutionary relationship were analyzed in comparison with epidemic rotavirus sequences obtained from GenBank.

Results

The two Guangzhou G8 strains were DS-1-like with the closest genetic distance to strains circulating in Southeast Asia. The VP7 genes of the two strains were derived from a human, not an animal G8 rotavirus. Large genetic distances in several genes suggested that the Guangzhou strains may not have been transmitted directly from Southeast Asian countries, but have emerged following reassortment events.

Conclusions

We report the whole genome sequence information of G8P[8] rotaviruses recently detected in China; their clinical and epidemiological significance remains to be explored further.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07542-9.

Prevalence and genotypes distribution of group A rotavirus among outpatient children under 5 years with acute diarrhea in Shanghai, China, 2012-2018

Background

Group A rotavirus (RVA) remains the main causative agent of acute diarrhea among children under five years in countries that have not yet introduced the RVA vaccine worldwide. Long-term and continuous monitoring data on RVA infection in outpatient children were lacking in Shanghai. We investigated the prevalence and distribution of RVA genotypes in outpatient children with acute diarrhea in Shanghai from 2012 to 2018.

Methods

Stool specimens of outpatient children under five years were collected from the Children’s Hospital of Fudan University in Shanghai, China. All the samples enrolled in this study were detected and characterized for the P and G genotypes of RVA were determined using the semi-multiplex RT-PCR technique.

Results

Of 1814 children enrolled with acute diarrhea and having specimens collected, 246 (13.6%) were infected with RVA. The highest frequency of RVA was observed in children younger than two years old (87.0%, 214/246). Year-round RVA transmission was observed and the RVA detection rate peaked every winter and troughed in summer. In this study, 12 different RVA strains were identified in children. G9P[8] (49.2%, 121/246) was detected as the most prevalent genotype, followed by G–P[8] (22.8%, 56/246), G3P[8] (11.4%, 28/246), and G9P- (4.9%, 12/246). Although RVA strains detected in this study varied with the time, G9P[8] has been the most predominant circulating genotype since 2012. Furthermore, 12.2% (30/246) RVA positive samples were co-infected with other diarrhea viruses.

Conclusion

The present analysis showed that RVA was still a major cause of children with acute diarrhea in Shanghai from 2012 to 2018. A great diversity of RVA strains circulated in children with acute diarrhea with G9P[8] being the predominant genotype since 2012. Long-term and continuous monitoring of RVA genotypes is therefore indispensable to refine future vaccine strategy in Shanghai.

Rotavirus Infection in Children <5 Years of Age in Suzhou, China, 2013-2019: Disease Burden, Genotype Distribution and Seasonality

BACKGROUND

This study aimed to determine the disease burden and strain distribution of rotavirus in children with diarrhea <5 years old in Suzhou, China.

METHODS

The study was conducted among children with diarrhea <5 years old at Suzhou University Affiliated Children's Hospital from 2013 to 2019. Rotavirus antigen was detected in clinical laboratory and then sent to Suzhou Centers for Disease Control and Prevention for further molecular analysis. Group A rotavirus (RVA) was detected through enzyme-linked immunosorbent assays, and G-genotype and P-genotype of RVA were tested using reverse transcription-polymerase chain reaction.

RESULTS

Of a total of 198,130 children with diarrhea, 70,813 (35.7%) were positive for RVA; RVA-related diarrhea was detected in 7798 (20.7%, n = 7798/37,710) inpatients and 63,015 (39.3%, n = 63,015/160,420) outpatients. Most children (92.0%, n = 65,171/70,813) positive for RVA were found as children <3 years old. Children 12-35 months old were reported as the highest prevalence among all age groups. The seasonal peak of RVA was in the autumn and winter. Among all 673 RVA strains genotyped, the G9P[8] strain was reported to be persistently predominant in the pediatric population from 2013 to 2019.

CONCLUSIONS

The burden of diarrhea disease due to rotavirus infection remains high in Suzhou.

Genotype Distribution and Evolutionary Analysis of Rotavirus Associated with Acute Diarrhea Outpatients in Hubei, China, 2013–2016

Group A human rotaviruses (RVAs) annually cause the deaths of 215,000 infants and young children. To understand the epidemiological characteristics and genetic evolution of RVAs, we performed sentinel surveillance on RVA prevalence in a rotavirus-surveillance network in Hubei, China. From 2013 to 2016, a total of 2007 fecal samples from hospital outpatients with acute gastroenteritis were collected from four cities of Hubei Province. Of the 2007 samples, 153 (7.62%) were identified positive for RVA by real-time RT-PCR. RVA infection in Hubei mainly occurred in autumn and winter. The highest detection rate of RVA infection was in 1–2 years old of outpatients (16.97%). No significant difference of RVA positive rate was observed between females and males. We performed a phylogenetic analysis of the G/P genotypes based on the partial VP7/VP4 gene sequences of RVAs. G9P[8] was the most predominant strain in all four years but the prevalence of G2P[4] genotype increased rapidly since 2014. We reconstructed the evolutionary time scale of RVAs in Hubei, and found that the evolutionary rates of the G9, G2, P[8], and P[4] genotypes of RVA were 1.069 ​× ​10⁻³, 1.029 ​× ​10⁻³, 1.283 ​× ​10⁻³ and 1.172 ​× ​10⁻³ nucleotide substitutions/site/year, respectively. Importantly, using a molecular clock model, we showed that most G9, G2, P[8], and P[4] genotype strains dated from the recent ancestor in 2005, 2005, 1993, and 2013, respectively. The finding of the distribution of RVAs in infants and young children in Hubei Province will contribute to the understanding of the epidemiological characteristics and genetic evolution of RVAs in China.

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A four-year study of sentinel surveillance program of RVAs was performed in Hubei, China.

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The key population of rotavirus infection is 1–2 years old of outpatients with acute gastroenteritis.

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G9P[8] was the most predominant strain between 2013 and 2016.

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The estimating time to the most recent common ancestor for the G9 genotype based on partial VP7 gene was 46 years.

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RVA distribution in Hubei Province contributes to the understanding of the epidemiological characteristics of RVAs in China.

Nonpharmaceutical interventions against the COVID-19 pandemic significantly decreased the spread of enterovirus in children

BACKGROUND

Precise prevention and control measures have been adopted to impede the transmission of COVID-19 in China. This study was performed to investigate the effect of protective measures on gastrointestinal infection in children during the COVID-19 pandemic.

METHODS

The data on the rotavirus and adenovirus antigen tests were collected in outpatient children due to gastroenteritis from January 1, 2019, to December 31, 2020, at the Children's Hospital of Zhejiang University School of Medicine. According to age and month distribution, the positive number and rate of rotavirus and adenovirus in 2020 were compared with 2019.

RESULTS

A 3.8-fold and 4-fold reduction in the number of rotavirus- and adenovirus-positive patients in 2020 were found, respectively. The overall positive rate of rotavirus and adenovirus infection was drastically decreased in 2020 (rotavirus 2020: 18.18% vs 2019: 9.75%, P < 0.001; adenovirus 2020: 3.13% vs 2019: 1.58%, P < 0.001). The proportions of rotavirus and adenovirus in all age groups in 2020 decreased compared with those in 2019. The highest frequency of rotavirus infection occurred among children aged 1-3 years both in 2019 and 2020 (2019: 27.95% vs 2020: 17.19%, P < 0.001), while adenovirus infection was detected in children aged 3-5 years, which had the highest percent positivity (2019: 8.19% vs 2020: 4.46%; P < 0.001). An obvious peak prevalence of rotavirus incidence was found during December-April, and the percent positivity of rotavirus significantly decreased in 2020 (December 2019: 24.26% vs 2020: 8.44%, P < 0.001; January 2019: 40.67% vs 2020: 38.18%, P < 0.05; February 2019: 40.73% vs 2020: 15.04%, P < 0.001; March 2019: 31.47% vs 2020: 7.88%, P < 0.001; April 2019: 15.52% vs 2020: 4.78%, P < 0.001). The positive rate of adenovirus distributed throughout 2019 was 1.91%-4.86%, while the percent positivity during 2020 in the same period was much lower (0.00%-3.58%).

CONCLUSIONS

Our results confirmed that the preventive and control measures adopted during the COVID-19 pandemic and the collateral benefit of these interventions have significantly decreased the transmission of rotavirus or adenovirus. This article is protected by copyright. All rights reserved.

Viral metagenomics reveals diverse viruses in the fecal samples of children with diarrhea

Diarrhea is the third leading cause of death in developing countries in children under the age of five. About half a million children die of diarrhea every year, most of which in developing countries. Viruses are the main pathogen of diarrhea. In China, the fecal virome of children with diarrhea has been rarely studied. Using an unbiased viral metagenomics approach, we analyzed the fecal virome in children with diarrhea. Many DNA or RNA viruses associated with diarrhea identified in those fecal samples were mainly from six families of Adenoviridae, Astroviridae, Caliciviridae, Parvoviridae, Picornaviridae, and Reoviridae. Among them, the family of Caliciviridae accounts for the largest proportion of 78.42%, following with Adenoviridae (8.94%) and Picornaviridae (8.36%). In addition to those diarrhea-related viruses that have already been confirmed to cause human diarrhea, the viruses not associated with diarrhea were also identified including anellovirus and picobirnavirus. This study increased our understanding of diarrheic children fecal virome and provided valuable information for the prevention and treatment of viral diarrhea in this area.

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Many DNA or RNA viruses associated with diarrhea were identified in this study.

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Viruses belonging to the family of Caliciviridae were the most main pathogen that induced children diarrhea.

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In addition to those diarrhea-related viruses, the viruses not associated with diarrhea were also identified.

Intestinal microbiota profiles in infants with acute gastroenteritis caused by rotavirus and norovirus infection: a prospective cohort study

OBJECTIVE

To compare the intestinal microbiota profiles in infants following rotavirus (RV) and human norovirus (HNoV) infection.

METHODS

Faecal specimens from 18 infants {mean age 11.8 months [standard deviation (SD) 3.0] months} with acute gastroenteritis caused by RV (G9P8) and 24 infants [mean age 8.8 (SD 6.4) months] with acute gastroenteritis caused by HNoV (GII) infection were collected prospectively. The faecal microbiome was assessed by 16S rRNA amplicon pyrosequencing. Alpha diversity, beta diversity, deferentially abundant taxa and microbial functions were assessed by bioinformatic analysis.

RESULTS

The Chao1 index for the HNoV group was significantly higher compared with the control group (P=0.0003), and was lower for the RV group compared with the HNoV group (P=0.0078). No significant difference in beta diversity was observed between the RV and HNoV groups. The RV group showed greater abundance of Actinobacteria at phylum level and Bifidobacterium spp., Streptococcus spp., Enterococcus spp. and Lactobacillus spp. at genus level. The HNoV group showed richness in Fusobacteria and Cyanobacteria at phylum level, and Enterococcus spp. and Streptococcus spp. at genus level. Bacillus was the characteristic genus in infected infants. In comparison with the control group, the viral group (P≤0.01), the RV group (P=0.002) and the HNoV group (P≤0.01) showed significant differences in potentially pathogenic bacteria.

CONCLUSIONS

Changes in microbiotic structure were observed in infants following RV and HNoV infection. The Chao 1 index of alpha diversity increased significantly in the HNoV group. Bacillus was the characteristic genus in infected infants. An increase in pathogenic bacteria, particularly Streptococcus spp. and Enterococcus spp., was detected in infected infants.

Molecular and epidemiological characterization of human adenovirus and classic human astrovirus in children with acute diarrhea in Shanghai, 2017-2018

BACKGROUND

In addition to rotavirus and norovirus, human adenovirus (HAdV) and classic human astrovirus (classic HAstV) are important pathogens of acute diarrhea in infants and young children. Here, we present the molecular epidemiology of HAdV and classic HAstV in children with acute diarrhea in Shanghai.

METHODS

Fecal specimens were collected from 804 outpatient infants and young children diagnosed with acute diarrhea in Shanghai from January 2017 to December 2018. All of the samples were screened for the presence of HAdV and classic HAstV. HAdV and classic HAstV were detected using traditional PCR and reverse-transcription PCR, respectively. All of the HAdV and classic HAstV positive samples were genotyped by phylogenetic analysis.

RESULTS

Among the 804 fecal samples, 8.58% (69/804) of samples were infected with either HAdV or classic HAstV, and five were co-infected with two diarrhea viruses. The overall detection rates of HAdV and classic HAstV were 3.47% (28/804) and 5.22% (42/804), respectively. Four subgroups (A, B, C, and F) and seven genotypes (HAdV-C1, -C2, -B3, -C5, -A31, -F40, and -F41) of HAdV were detected. Subgroup F had the highest constituent ratio at 64.29% (18/28), followed by non-enteric HAdV of subgroup C (21.43%, 6/28) and subgroup B 10.71% (3/28). HAdV-F41 (60.71%, 17/28) was the dominant genotype, followed by HAdV-C2 (14.29%, 4/28) and HAdV-B3 (10.71%, 3/28). Two genotypes of classic HAstV (HAstV-1 and HAstV-5) were identified in 42 samples during the study period; HAstV-1 (95.24%, 40/42) was the predominant genotype, and the other two strains were genotyped as HAstV-5. No significant differences were found between boys and girls in the detection rates of HAdV (P = 0.604) and classic HAstV (P = 0.275). Over half of the HAdV infections (82.14%, 23/28) and classic HAstV infections (66.67%, 28/42) occurred in children less than 36 months. Seasonal preferences of HAdV and classic HAstV infections were summer and winter, respectively. In this study, the common clinical symptoms of children with acute diarrhea were diarrhea, vomiting, fever and abdominal pain.

CONCLUSIONS

Our findings indicate that HAdV and classic HAstV play important roles in the pathogenesis of acute diarrhea in children in Shanghai. Systematic and long-term surveillance of HAdV and classic HAstV are needed to monitor their prevalence in children and prevent major outbreak.

Clinical and molecular epidemiological characterization of rotavirus infections in children under five years old in Shandong province, China

Rotaviruses are important causative agents of acute gastroenteritis in children. In China, rotavirus infection has a prevalence rate of 30% and is therefore considered a serious public health problem. This study was carried out to investigate the clinical and molecular epidemiological characteristics of rotavirus infections in children under 5 years old with acute diarrhea in Shandong province, China. From July 2017 to June 2018, a total of 1211 fecal specimens were tested, and the prevalence of rotavirus infection was 32.12%. The mean age of the infected children was 12.2 ± 10.9 months, and the highest infection rate was observed in children aged 7-12 months, with a rate of 41.64%. G9P[8] (76.61%) was the most prevalent genotype combination, followed by G2P[4] (7.20%), G3P[8] (3.60%), and G9P[4] (2.06%). In addition to diarrhea, vomiting, fever, and dehydration were the most common clinical signs. In general, there was no significant difference in clinical manifestations among different age groups. However, the clinical manifestations differed significantly between vaccinated and unvaccinated children. Vaccinated children showed lower incidence and frequency of vomiting, lower incidence and degree of dehydration, and lower incidence of severe cases than unvaccinated children. These findings suggest that it is necessary to continuously monitor changes in the characteristics of rotavirus infections. Moreover, the introduction of vaccines into the national immunization program to prevent and control rotavirus infection is needed in China.

Infection status and circulating strains of rotaviruses in Chinese children younger than 5-years old from 2011 to 2018: systematic review and meta-analysis

To evaluate rotavirus (RV) disease burden and circulating strains of RV among Chinese children younger than 5-years old who had diarrhea from 2011 to 2018. PubMed, Web of Science, Embase, CNKI and WANFANG databases were systematically searched to identify studies that reported RV prevalence in mainland China. After data extraction, a fixed-effects model or a random-effects model was applied to estimate RV positivity and proportions of G and P types. Statistical analysis was conducted using R software. We initially reviewed 1323 studies, and identified 69 studies that were eligible. The overall proportion of RV gastroenteritis (RVGE) among children under 5-years old who presented with diarrhea and sought medical care was 34.0% (95% CI: 31.3, 36.8), and RV positivity was higher among inpatients (39.7%) than outpatients (23.9%). Western areas of China had the highest proportion of RVGE (42.7%), and RV positivity was highest for children who were 6 months-old to 2 years-old. The most prevalent G types were G3 (26.1%), G9 (17.5%), and G1 (12.8%), the most prevalent P type was P[8] (56.8%) and the most prevalent G-P combination was G9P[8] (20.9%). RV continues to be a main cause of acute gastroenteritis in Chinese children who are younger than 5 years old. Following the introduction of an RV vaccine in 2011, monitoring of the disease burden of RV diarrhea and circulating strains in China remain important for assessments of vaccine efficacy.

The association between short-term exposure to air pollutants and rotavirus infection in Wuhan, China

BACKGROUND

The impact of various meteorological factors on rotavirus (RV) infection has been previously studied; however, few studies have explored the association between short-term exposure to air pollutants and RV infection.

METHODS

Daily RV positive cases among children aged 0-6 years were collected from July 2014 to August 2019 in Tongji hospital (Wuhan, China). Daily data on air temperature and air pollutants were obtained from the China Meteorological Network. A distributed lag model to explore the lagged effects of short-term exposure to air pollutants and RV infection was performed. The distribution lag model was used to study the lag effect of short-term exposure to air pollutants and RV infection.

RESULTS

RV infection was negatively correlated with mean air temperature and O₃ concentration. The RV infection risk decreased by 5.2% and 0.47% for every 1℃ increase in average temperature and 1 ug/m³ increase in O₃ concentration, respectively. Increased PM_2.5 , SO₂ , and NO₂ concentrations were independent risk factors for an increase in positive rates; their relative risk values were 1.0014 (95% confidence interval [CI], 1.0013-1.0015), 1.0050 (95% CI, 1.0047-1.0053), and 1.0030 (95% CI, 1.0028-1.0032), respectively. The highest RV-positive rates were from January to March and November to December. Additionally, children <18 months of age and boys were more vulnerable to infection.

CONCLUSIONS

Air pollutants were important factors impacting the RV-positivity of children in Wuhan. These findings may help develop an early environment-based warning system to prevent and control RV infection.

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].

Epidemiology and Viral Etiology of Pediatric Immune Thrombocytopenia through Korean Public Health Data Analysis

Immune thrombocytopenic purpura (ITP) is prevalent in children aged 2-5 years but may occur in all pediatric age groups. In 50-60% of pediatric patients, ITP is preceded by an upper respiratory tract infection 1-4 weeks before its onset. In this study, the relationship between the development of ITP and viral infections in children was assessed. We analyzed data of 6487 patients aged < 18 years with incident ITP from the Health Insurance Review and Assessment Open Access Big Data Platform (2015 to 2018) and the Korea Disease Control and Prevention Agency. The monthly positive detection rate (PDR) of seven respiratory and four acute diarrhea viruses was calculated. The virus PDR seasonal trend data was analyzed through ARIMA modeling. The ITP diagnostic data and prevalence of viral infection 1 and 2 months prior were analyzed using the Granger test. The overall male to female (M/F) ratio was 1.2, whereas it was 1.4 in the youngest age group (< 1 year). The overall ITP incidence rate was 18.1 per 100,000 person-years. Respiratory syncytial virus, rhinovirus, rotavirus, and astrovirus infections influenced ITP occurrence in children. However, rotavirus infection is positively associated with the etiology of ITP after 1-2 months.

Prevalence and genotype distribution of group A rotavirus circulating in Shanxi Province, China during 2015-2019

BACKGROUND

Group A rotavirus (RVA), despite being a leading cause of gastroenteritis in infants and young children, is less studied in Shanxi Province, China. The current study was conducted to determine the prevalence and genetic characterization of RVA in hospitalized children younger than 10 years of age with the diagnosis of acute gastroenteritis in Shanxi Province, China.

METHODS

A hospital-based active surveillance of rotavirus gastroenteritis was conducted at Children's Hospital of Shanxi from Jan 1, 2015, through Dec 31, 2019. Rotavirus was detected in stool samples by real-time quantitative reverse transcription PCR (qRT-PCR). G- and P-genotypes were determined by reverse transcription PCR (RT-PCR) and nucleotide sequencing.

RESULTS

A total of 961 children younger than 10 years of age was enrolled over the study period, of whom 183 (19.0%) were positive for RVA. The highest RVA-infection frequency (23.7%) was found among children aged 12-23 months, and the seasonal peak was in December. G9P[8] was most prevalent (76.0%), followed by G3P[8] (7.1%), G2P[4] (3.3%), G1P[8] (0.5%) and G9P[4] (0.5%).

CONCLUSIONS

These results report for the first time that RVA was one of the main causes of severe infectious gastroenteritis in children, and a high proportion of G9P[8] strains circulating in most areas of Shanxi Province. While the protective efficacy of the rotavirus vaccines has been demonstrated against G9P[8] strains, our results highlight that the dominant strains have not been effectively controlled in China.

Rapid and sensitive detection of rotavirus by surface-enhanced Raman scattering immunochromatography

A surface-enhanced Raman scattering (SERS) immunochromatographic assay (ICA) has been developed for rapid, ultrasensitive, and quantitative detection of rotavirus in feces using double Raman molecule-labeled Au-core Ag-shell nanoparticles. The Raman signals are generated by 5,5'-dithiobis-(2-nitrobenzoic acid) and the intensity of the characteristic peak at 1334^-1 cm was detected as the analytical signal. The Raman signals were enhanced by the SERS-enhanced effect of both Au and Ag, the large amount of Raman molecules, and the hot-spot effect in the narrow gap between the Au core and Ag shell. The SERS ICA can quantitatively detect rotavirus in a concentration range of 8- 40,000 pg/mL, with detection limits of 80 pg/mL and 8 pg/mL based on naked eye observation and SERS signal detection, respectively. No cross-reaction was observed from other common pathogens. The standard deviation of the intra- and inter-batch repetitive tests is less than 10%, and the coincidence between SERS ICA and RT-qPCR as well as commercial colloidal gold ICA is 100%. The results indicated that this SERS ICA is able to quantitatively detect rotavirus in feces in 20 min with high sensitivity, selectivity, reproducibility, and accuracy and might be a promising method for the early detection of rotavirus in clinical analysis.

Surveillance of Human Rotavirus in Wuhan, China (2011-2019): Predominance of G9P[8] and Emergence of G12

Rotaviruses are a major etiologic agent of gastroenteritis in infants and young children worldwide. To learn the shift of genotypes and genetic characteristics of Rotavirus A (RVA) causing diarrhea in children and adults, a hospital-based surveillance of rotavirus was conducted in Wuhan, China from June 2011 through May 2019, and representative virus strains were phylogenetically analyzed. Among a total of 6733 stool specimens collected from both children and adults with acute gastroenteritis, RVA was detected in 25.5% (1125/4409) and 12.3% (285/2324) of specimens, respectively. G9P[⁸] was the most common genotype (74.5%), followed by G1P[⁸] (8.7%), G2P[⁴] (8.4%), and G3P[⁸] (7.3%), with G9P[⁸] increasing rapidly during the study period. The predominant genotype shifted from G1P[⁸] to G9P[⁸] in 2012-2013 epidemic season. G12P[⁶] strain RVA/Human-wt/CHN/Z2761/2019/G12P[⁶] was detected in April 2019 and assigned to G12-P[⁶]-I1-R1-C1-M1-A1-N1-T2-E1-H1 genotypes. Phylogenetic analysis revealed that VP7, VP4, VP6, VP3, NSP1, NSP2, and NSP5 genes of Z2761 clustered closely with those of Korean G12P[⁶] strain CAU_214, showing high nucleotide identities (98.0-98.8%). The NSP3 gene of Z2761 was closely related to those of G2P[⁴] and G12P[⁶] rotaviruses in Asia. All the eleven gene segments of Z2761 kept distance from those of cocirculating G9P[⁸], G1P[⁸], and G3P[⁸] strains detected in Wuhan during this study period. This is the first identification of G12 rotavirus in China. It is deduced that Z2761 is a reassortant having DS-1-like NSP3 gene in the background of G12P[⁶] rotavirus genetically close to CAU_214.

Genetic diversity of group A rotavirus in acute gastroenteritis outpatients in Shanghai from 2017 to 2018

Background

Group A Rotavirus (RVA), despite being an important pathogen in hospitalized children, is less studied in pediatric outpatients, and even rarely investigated in adults. This study aims to understand the genetic diversity of RVA in outpatients across all age groups in Shanghai, and thus providing a molecular basis for vaccine implementation and evaluation.

Methods

Stool samples were first screened by Real-time Reverse Transcription Polymerase Chain Reaction (rRT-PCR). RVA genotyping was performed through the amplification of partial VP7 and VP4 gene. Strains of interest were further sequenced and analyzed using MEGA 6.0.

Results

Four thousand nine hundred one samples were collected, from which 7.61% (373 cases) were screened positive for RVA. RVA prevalence was higher in children (9.30%) than in adults (7.21%) (χ² = 4.72, P < 0.05). 9.38% RVA positive cases had taken antibiotics before hospital visit while 49.60% had been prescribed antibiotics afterwards. RVA displayed a strong seasonality in both adults and children with a shared commonality in genotype repertoire, where G9P[8] was the most prevalent strain (67.96%) followed by G3P[8] (15.49%) and G1P[8] (12.32%). Meanwhile the first local case of fecal shedding of the G10P[15] vaccine strain was also discovered.

Conclusions

While the prevalence of rotavirus is highest during cold seasons, it is revealed for the first time that G9P[8] is the predominant genotype in both adults and pediatric outpatients. Clinically, higher occurrence of nausea or vomiting was observed in RVA positive cases. Antibiotic overuse was implicated in both non-clinical and clinical settings. The finding emphasizes the importance of RVA genotyping in surveillance as it provides the basis for new vaccine application as well as a baseline for future vaccine efficacy evaluation.

Clinical and Environmental Surveillance of Rotavirus Common Genotypes Showed High Prevalence of Common P Genotypes in Egypt

The objective of this study was to compare the prevalence of human rotavirus group A common G and P genotypes in human Egyptian stool specimens and raw sewage samples to determine the most common genotypes for future vaccine development. From 1026 stool specimens of children with acute diarrhea and using nested RT-PCR, 250 samples (24.37%) were positive for human rotavirus group A. Using multiplex RT-PCR, rotavirus common P and G genotypes were detected as 89.20% and 46.40% of the positive clinical specimens respectively. This low percentage of common G genotypes frequency may affect the efficiency of the available live attenuated oral rotavirus vaccines [Rotarix® (human rotavirus G1P[8]) and RotaTeq® (reassortant bovine-human rotavirus G1-4P[5] and G6P[8])], however the percentage of clinical specimens which were negative for common G genotypes but positive for P[8] genotype was 12.00%. From 24 positive raw sewage samples for rotavirus group A VP6 collected from Zenin and El-Gabal El-Asfar wastewater treatment plants (WWTPs), 21 samples (87.50%) were typeable for common P genotypes while 13 samples (54.17%) were typeable for common G genotypes. Phylogenetic analysis of a VP8 partial gene of 45 P-typeable clinical isolates and 20 P-typeable raw sewage samples showed high similarity to reference strains and the majority of mutations were silent and showed lower to non-significant similarity with the two vaccine strains. This finding is useful for determining the most common antigens required for future vaccine development.

Efficacy, immunogenicity and safety of a trivalent live human-lamb reassortant rotavirus vaccine (LLR3) in healthy Chinese infants: A randomized, double-blind, placebo-controlled trial

BACKGROUND

A randomized, double-blind, placebo-controlled multicenter trial was conducted in healthy Chinese infants to assess the efficacy, immunogenicity and safety of a novel trivalent live human-lamb reassortant rotavirus vaccine (LLR3) against rotavirus gastroenteritis (RVGE).

METHODS

Healthy children aged 6-13 weeks were enrolled and randomized (1:1) to either 3 oral doses of LLR3 or placebo according to a 0, 1, 2 month schedule. The objectives were to evaluate vaccine efficacy (VE) against RVGE of any-severity, severe RVGE (sRVGE) and inpatient caused by rotavirus serotypes contained in the vaccine and not contained in the vaccine after the third dose. Immunogenicity was also assayed in a subgroup. All adverse events (AEs) were collected from 30 min after each dose for immediate reaction, even to the entire study period, including the serious AEs (SAEs) and intussusception.

RESULTS

VE against RVGE of any-severity, sRVGE and inpatient caused by any serotype was 56.6% (95% CI: 50.7, 61.8), 70.3% (95% CI: 60.6, 77.6) and 74.0% (95% CI: 57.5, 84.1) respectively. VE against RVGE of any-severity, sRVGE caused by serotypes not contained in vaccine were 54.2% (95% CI: 47.5, 60.1) and 70.4% (95% CI: 60.4, 77.9). The rate of seroconversion and four-fold increase of rotavirus serotype G2-, G3-, and G4-specific IgA is 60.8%, 58.0%, and 60.6% in vaccine group, which was higher than 21.35%, 22.7%, and 23.1% in placebo group (p < 0.0001 for G2, G3, G4), as well as the Geometric Mean Titer (GMT). Through the entire trial, 65.91% and 67.79% of participants reported at least one AE, and 0.02% and 0.02% reported SAEs in the vaccine and placebo groups, respectively. Two intussusception cases were reported both in vaccine and placebo group.

CONCLUSIONS

In Chinese infants, LLR3 provided a substantial protection against RVGE of any-severity, sRVGE and inpatient caused by any serotype, and showed well immunogenicity and safety.

Molecular epidemiology of rotavirus A and adenovirus among children with acute diarrhea in Hangzhou, China

Background

Rotavirus A (RVA) and adenovirus (Adv) are important causes of acute diarrhea in children. RVAs are classified into G and P genotypes based on viral proteins (VP)7 and VP4 gene and Adv contains over 70 genotypes based on hexon and fiber gene. This study aimed to characterize the molecular epidemiology of RVA and Adv in children with acute diarrhea during 2017-2018 in Hangzhou.

Methods

The stool samples were collected and tested for RVA and Adv by reverse transcription-quantitative PCR (RT-qPCR) assay. The RVA positive samples were detected by RT-PCR for VP7(G) and VP4([P]) genotypes, and the Adv positive samples were detected by PCR for genotyping by the target to hexon gene.

Results

Among 228 RVA-positive samples, G9 was detected as the most frequent genotype (195/228, 85.5%), followed by G3 (20/228, 8.8%), G2 (7/228, 3.1%) and G1 (6/228, 2.6%). G9 strains were closely related to strains from China and neighboring countries, as well as the USA. On the other hand, P[8] strains were detected in 219 (96.1%) samples with most closely related to one strain from Malawi, and P[4] in 9 (3.9%) samples. G9P[8] (84.6%, 193/228) was the most prevalent rotavirus A strains, followed by G3P[8] (8.8%, 20/228), G2P[4] (3.1%, 7/228), G1P[8] (2.6%, 6/228) and G9P[4] (0.9%, 2/228). Of 167 Adv-positive cases, 2 different genotypes were identified with 152 (91.0%) of Adv-41and 15 (9%) of Adv-40. All Adv strains were closely related to prototype strains of Adv types 40 and 41 in India.

Conclusions

G9P[8] of RVA and Adv-41 were the most common genotypes that caused children's acute diarrhea in Hangzhou, 2017-2018.

Epidemiology and HBGA-susceptibility investigation of a G9P[8] rotavirus outbreak in a school in Lechang, China

Rotaviruses cause severe gastroenteritis in infants, in which the viruses interact with human histo-blood group antigens (HBGAs) as attachment and host susceptibility factors. While gastroenteritis outbreaks caused by rotaviruses are uncommon in adolescents, we reported here one that occurred in a middle school in China. Rectal swabs and saliva samples were collected from symptomatic and asymptomatic students, and samples were also collected from the environment. Using PCR, followed by DNA sequencing, a single G9P[8] rotavirus strain was identified as the causative agent. The attack rate of the outbreak was 13.5% for boarders, which was significantly higher than that of day students (1.8%). Person-to-person transmission was the most plausible transmission mode. The HBGA phenotypes of the individuals in the study were determined by enzyme immunoassay, using saliva samples, while recombinant VP8* protein of the causative rotavirus strain was produced for HBGA binding assays to evaluate the host susceptibility. Our data showed that secretor individuals had a significantly higher risk of infection than nonsecretors. Accordingly, the VP8* protein bound nearly all secretor saliva samples, but not those of nonsecretors, explaining the observed infection of secretor individuals only. This is the first single-outbreak-based investigation showing that P[8] rotavirus infected only secretors. Our investigation also suggests that health education of school students is an important countermeasure against an outbreak of communicable disease.

Structural Basis of Glycan Recognition in Globally Predominant Human P[8] Rotavirus

Rotavirus (RV) causes acute gastroenteritis in infants and children worldwide. Recent studies showed that glycans such as histo-blood group antigens (HBGAs) function as cell attachment factors affecting RV host susceptibility and prevalence. P[8] is the predominant RV genotype in humans, but the structural basis of how P[8] RVs interact with glycan ligands remains elusive. In this study, we characterized the interactions between P[8] VP8*s and glycans which showed that VP8*, the RV glycan binding domain, recognized both mucin core 2 and H type 1 antigens according to the ELISA-based oligosaccharide binding assays. Importantly, we determined the structural basis of P[8] RV-glycans interaction from the crystal structures of a Rotateq P[8] VP8* in complex with core 2 and H type 1 glycans at 1.8 Å and 2.3 Å, respectively, revealing a common binding pocket and similar binding mode. Structural and sequence analysis demonstrated that the glycan binding site is conserved among RVs in the P[II] genogroup, while genotype-specific amino acid variations determined different glycan binding preference. Our data elucidated the detailed structural basis of the interactions between human P[8] RVs and different host glycan factors, shedding light on RV infection, epidemiology, and development of anti-viral agents.

Molecular epidemiology of group A rotavirus in outpatient diarrhea infants and children in Chongqing, China, 2011-2015

Human group A rotavirus (RVA) is the leading cause of acute viral gastroenteritis in children under 5 years old worldwide. The aim of this study was to investigate the genotype distribution of RVA in the Midwest of China. Sentinel-based surveillance of acute diarrhea was conducted at Children's Hospital of Chongqing Medical University from 2011 to 2015. RVA was tested by using enzyme-linked immunosorbent assays. The partial VP4 genes and VP7 genes of rotavirus were amplified and sequenced, and genotyping and phylogenetic analyses were performed. Among the 2236 stool specimens collected from children with acute gastroenteritis, 681 (30.46%) were positive for RVA. The majority of children (89.28%) who tested positive for RVA were children aged ≤2 years. The seasonal peak of RVA was in the winter. As for genotype, four strain combinations, G9P[8], G3P[8], G1P[8], and G2P[4] contributed to 75.62% (515/681) of the RVA-associated diarrhea cases. After a marked increase in G9P[8] (30.77%) in 2013, G9P[8] became the predominant genotype in 2014 and 2015, whilst the prevalence of G1P[8] was decreased to 2.72% in 2015. Unusual G-P combinations (eg, G1P[4], G9P[4], G4P[6], G3P[4], G2P[8]) were also detected sporadically over the study period. Phylogenetic tree analysis results showed that the VP7 sequences of G9 strains were clustered into two main lineages, and 77.34% of them were clustered into lineage VI, with the highest nucleotide similarity to the strain JS12-17(China). VP4 gene sequences of P[8] strains were almost P[8]-lineage 3. Substantial temporal variation in the circulation of various genotypes of rotavirus in Chongqing was observed during 2011-2015, and highlights the need for continuous surveillance of RVA infection for better understanding and control of RVA infection.

Prevalence and genetic diversity of human sapovirus associated with sporadic acute gastroenteritis in South China from 2013 to 2017

Human sapovirus (SaV) is an important viral agent for acute diarrhea worldwide, but timely prevalence data of human SaV in South China are still lacking. In this study, a 4-year surveillance was conducted to characterize the prevalence and genetic characteristics of the circulating SaV associated with sporadic diarrhea in South China. From November 2013 to October 2017, 569 fecal samples from patients with acute diarrhea were collected. SaV was detected in 11 samples with a positive rate of 1.93%. Three human genogroups of GI, GII, and GIV were identified, including five GI.1 strains, three GI.2 strains, one GI.3 strain, one GII.8 strain, and one GIV strain. Furthermore, multiple alignments of complete capsid protein VP1 genes of five local GI.1 strains and other available GI.1 strains in GenBank were performed. Average pairwise identities were calculated at 95.33% and 99.36% at nucleotide and amino acid levels, and only six variable amino acid sites were found during its 36-years' evolution process. GI.1 strains could be further phylogenetically divided into four clusters with an approximate temporal evolution pattern, and local strains belonged to Cluster-d with other four strains from China and Japan. In summary, SaV was identified as an etiological agent responsible for sporadic gastroenteritis in Guangzhou with a low prevalence rate as in other Chinese cities, but its high genetic diversity suggested the necessity of continuous SaV surveillance in the future.

Bovine colostrum and product intervention associated with relief of childhood infectious diarrhea

This meta-analysis aimed to investigate the protective effects of bovine colostrum against childhood infectious diarrhea. A systematic search was conducted using PubMed, Cochrane Library databases and clinicaltrial.gov. Among 166 research articles, only five RCTs were included into final analysis. Review manager (version 5.2) was used to pool the effect-size across studies. Sensitivity and risk of bias were estimated accordingly. Under a pooled analysis, bovine colostrum consumption correlated with a significant reduction in stool frequency of infectious diarrhea, by 1.42 times per day (95% CI: -2.70, -0.14). Bovine colostrum intervention also reduced occurrence of diarrhea by 71% (pooled OR = 0.29, 95%CI 0.16, 0.52). The OR of positive detection of pathogen in the stool was 0.29 (95%CI 0.08, 0.71) in bovine colostrum treated group, compared with placebo group. In the sensitivity analysis of studies with low risk of biases, bovine colostrum significantly reduced stool frequency, occurrence of diarrhea and pathogen detection. BC and related products have a significant benefit in reducing the frequency and relieving the symptoms of childhood infectious diarrhea.

Genome analysis of a G9P[23] group A rotavirus isolated from a dog with diarrhea in China

Genotype G9 is an emerging genotype among species A rotavirus (RVA) circulating in humans and pigs worldwide. In this study, an RVA strain designated RVA/Dog-tc/CHN/SCCD-A/2017/G9P[23] was isolated in cell culture from a pet dog stool sample with acute diarrhea, and its whole genome was sequenced. The genotype constellation of SCCD-A was G9-P[23]-I5-R1-C1-M1-A8-N1-T1-E1-H1. All genome segments except the VP1 gene were closely related to the genes from porcine RVA strains or porcine-like human RVA strains. On the other hand, the VP1 gene clustered in a distinct lineage only with that of a G5P[6] porcine-like human RVA, preventing the identification of the exact host species origin, but very unlikely to be originated from human RVA. In addition, phylogenetic analysis showed that the G9 VP7 gene of SCCD-A clustered into a novel sublineage within the lineage III of G9. This first isolation of a G9P[23] RVA from a pet dog may justify the exploration of the role dogs play in the interaction of RVA circulating in pigs and humans.

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First identified G9P[23] group A rotavirus from dog and the genome of RVA/Dog-tc/CHN/SCCD-A/2017/G9P[23]was determined.

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The strain’s genotype constellation as G9-P[23]-I5-R1-C1-M1-A8-N1-T1-E1-H1.

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G9P[23] from dog may justify the exploration of the role dogs play in the interaction of RVA circulating in pigs and humans.

The evolving epidemiology of rotavirus A infection in Brazil a decade after the introduction of universal vaccination with Rotarix®

Background

Brazil introduced the monovalent rotavirus vaccine (Rotarix®) in 2006. This study aimed to assess the epidemiology and genotype distribution of species-A rotavirus (RVA) in Brazil, comparing the pre- and post-vaccination periods.

Methods

Laboratory-based RVA surveillance included 866 municipalities in 22 Brazilian states, over a 21-year period. A total of 16,185 children with diarrheal diseases (DD) aged up to 12 years between 1996 and 2005 (pre-vaccination period, n = 7030) and from 2006 to 2017 (post-vaccination period, n = 9155) were enrolled. RVA was detected using ELISA immune assay and/or polyacrylamide gel electrophoresis and genotyped using nested PCR and/or nucleotide sequencing. RVA-positivity and genotypes detection rates were compared in distinct periods and age groups and Rotarix vaccination status.

Results

RVA-positivity in pre- and post-vaccination periods was, respectively: 4–11 months bracket, 33.3% (668/2006) and 16.3% (415/2547) (p <  0.001); 12–24 months, 28.2% (607/2154) and 22.2% (680/3068) (p <  0.001); 25–48 months, 17.4% (215/1235) and 29.4% (505/1720) (p <  0.001). Genotypes distribution in the pre- and post-vaccination periods was, respectively: G1P [8]/G1P[Not Typed], 417/855 (48.8%) and 118/1835 (6.4%) (p <  0.001); G2P [4]/G2P[NT], 47/855 (5.5%) and 838/1835 (45.7%) (p <  0.001); G3P [8]/G3P[NT], 55/855 (6.4%) and 253/1835 (13.8%) (p <  0.001); G9P [8]/G9P[NT], 238/855 (27.8%) and 152/1835 (8.3%) (p <  0.001); G12P [8]/G129P[NT], 0/871 (0%) and 249/1835(13.6%) (p <  0.001). Concerning infants aged 4–11 months, RVA frequency in fully vaccinated and non-vaccinated individuals was 11.9% (125/1052) and 24.5% (58/237) (p <  0.001), respectively. In children aged 12–24 months, RVA detection rate was 18.1% (253/1395) and 29.6% (77/260) (p <  0.001), for the vaccinated and non-vaccinated individuals, respectively (p <  0.001).

Conclusions

RVA infection was significantly less frequent in children aged ≤2 years with DD after implementing vaccination, mainly among vaccinated children. It was also observed a decrease of P [8] circulation and emergence of G2P[4] in 2005, and afterwards in the post-vaccine era, with spreading of G12P[8] in 2014–2015 and of G3P[8] in 2017. Continuous RVA surveillance must be carried out in this scenario.