Prevalence and genotypes of group A rotavirus among outpatient children under five years old with diarrhea in Beijing, China, 2011-2016

Epidemiological, molecular, and evolutionary characteristics of G1P[8] rotavirus in China on the eve of RotaTeq application

Introduction

This study, conducted in China prior to RotaTeq's launch, examined the epidemiological, molecular, and evolutionary features of the G1P[8] genotype RVA in children admitted with diarrhea, to aid in evaluating its efficacy and impact on G1P[8] RVA in China.

Methods

Data from the Chinese viral diarrhea surveillance network were collected from January 2016 to December 2018. RVA strains identified as the G1P[8] genotype were subjected to whole-genome sequencing. Neutralizing epitope, amino acid selection pressure, and evolution dynamics analyses on VP7 and VP4 were performed using BioEdit v.7.0.9.0 and PyMOL v.2.5.2, four algorithms (MEME, SLAC, FEL, and FUBAR) in the Datamonkey online software, and the MCMC model in BEAST v. 1.10.4, respectively. Phylogenetic and identity features of 11 genes were assessed by DNAStar and MEGA v.7.

Results

Results showed that the detection rate of G1P[8] in China from 2016 to 2018 was generally low with significant seasonality. The whole genome of G1P[8] of four 2016 childhood diarrhea specimens was successfully sequenced. Phylogenetic and neutralizing epitope analysis showed that Rotavin-M1 might have better protection on G1P[8] prevalent in China than Rotarix and RotaTeq. Two conserved N-glycosylation sites on VP7 of Chinese G1P[8] might affect the protective effect of the vaccine. Evolution rate and selection pressure analysis identified the possibility of rapidly evolving and adapting to the new environment introduced by vaccines of G1P[8], whereas positive selection specific to VP4 indicated the potential tendency to select for dominant traits. Identity and phylogeny analysis showed that Chinese G1P[8] from before 2018 was generally stable with possible genetic recombination among local strains.

Discussion

These findings not only are of great significance for predicting the prevalence of G1P [8] in China, but also provide data reference for evaluating rotavirus vaccine efficacy.

Rotavirus outbreaks in China, 1982-2021: a systematic review

Background

Rotavirus is globally recognized as an important cause of acute gastroenteritis in young children. Whereas previous studies focused more on sporadic diarrhea, the epidemiological characteristics of rotavirus outbreaks have not been systematically understood.

Methods

This systematic review was carried out according to the Preferred Reporting Items for Systematic Review and Meta-Analysis standards, WANFANG, China National Knowledge Infrastructure (CNKI), PubMed, and Web of Science databases were searched from database inception to February 20, 2022. We used SPSS 21.0 statistical software for data analysis, RStudio1.4.1717, and ArcGIS trial version for plotting bar graphs and maps.

Results

Among 1,596 articles, 78 were included, with 92 rotavirus outbreaks and 96,128 cases. Most outbreaks (67.39%, 62/92) occurred in winter and spring. The number of rotavirus outbreaks reported in the eastern region was more than that in the western region. Outbreaks were most commonly reported in villages (33/92, 35.87%), followed by hospitals (19, 20.65%). The outbreak duration was longer in factories and workers' living places, and villages, while it was shorter in hospitals. Waterborne transmission was the main transmission mode, with the longest duration and the largest number of cases. Rotavirus groups were identified in 66 outbreaks, with 40 outbreaks (60.61%) caused by Group B rotaviruses and 26 outbreaks (39.39%) caused by Group A rotaviruses. Significant differences were found in duration, number of cases, settings, population distribution, and transmission modes between Groups A and B rotavirus outbreaks.

Conclusion

Rotavirus is an important cause of acute gastroenteritis outbreaks in China. It should also be considered in the investigation of acute gastroenteritis outbreaks, especially norovirus-negative outbreaks.

Genetic diversity of G9, G3, G8 and G1 rotavirus group A strains circulating among children with acute gastroenteritis in Vietnam from 2016 to 2021

Rotavirus group A (RVA) is the most common cause of severe childhood diarrhea worldwide. The introduction of rotavirus vaccination programs has contributed to a reduction in hospitalizations and mortality caused by RVA. From 2016 to 2021, we conducted surveillance to monitor RVA prevalence and genotype distribution in Nam Dinh and Thua Thien Hue (TT Hue) provinces where a pilot Rotavin-M1 vaccine (Vietnam) implementation took place from 2017 to 2020. Out of 6626 stool samples, RVA was detected in 2164 (32.6%) by ELISA. RT-PCR using type-specific primers were used to determine the G and P genotypes of RVA-positive specimens. Whole genome sequences of a subset of 52 specimens randomly selected from 2016 to 2021 were mapped using next-generation sequencing. From 2016 to 2021, the G9, G3 and G8 strains dominated, with detected frequencies of 39%, 23%, and 19%, respectively; of which, the most common genotypes identified were G9P[8], G3P[8] and G8P[8]. G1 strains re-emerged in Nam Dinh and TT Hue (29.5% and 11.9%, respectively) from 2020 to 2021. G3 prevalence decreased from 74% to 20% in TT Hue and from 21% to 13% in Nam Dinh province between 2017 and 2021. The G3 strains consisted of 52% human typical G3 (hG3) and 47% equine-like G3 (eG3). Full genome analysis showed substantial diversity among the circulating G3 strains with different backgrounds relating to equine and feline viruses. G9 prevalence decreased sharply from 2016 to 2021 in both provinces. G8 strains peaked during 2019-2020 in Nam Dinh and TT Hue provinces (68% and 46%, respectively). Most G8 and G9 strains had no genetic differences over the surveillance period with very high nucleotide similarities of 99.2-99.9% and 99.1-99.7%, respectively. The G1 strains were not derived from the RVA vaccine. Changes in the genotype distribution and substantial diversity among circulating strains were detected throughout the surveillance period and differed between the two provinces. Determining vaccine effectiveness against circulating strains over time will be important to ensure that observed changes are due to natural secular variation and not from vaccine pressure.

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.

Increase in rotavirus prevalence with the emergence of genotype G9P[8] in replacement of genotype G12P[6] in Sabah, Malaysia

Rotaviruses are major causative agents of acute diarrhea in children under 5 years of age in Malaysia. However, a rotavirus vaccine has not been included in the national vaccination program. To date, only two studies have been carried out in the state of Sabah, Malaysia, although children in this state are at risk of diarrheal diseases. Previous studies showed that 16%-17% of cases of diarrhea were caused by rotaviruses and that equine-like G3 rotavirus strains are predominant. Because the prevalence of rotaviruses and their genotype distribution vary over time, this study was conducted at four government healthcare facilities from September 2019 through February 2020. Our study revealed that the proportion of rotavirus diarrhea increased significantly to 37.2% (51/137) after the emergence of the G9P[8] genotype in replacement of the G12P[8] genotype. Although equine-like G3P[8] strains remain the predominant rotaviruses circulating among children, the Sabahan G9P[8] strain belonged to lineage VI and was phylogenetically related to strains from other countries. A comparison of the Sabahan G9 strains with the G9 vaccine strains used in the RotaSiil and Rotavac vaccines revealed several mismatches in neutralizing epitopes, indicating that these vaccines might not be effective in Sabahan children. However, a vaccine trial may be necessary to understand the precise effects of vaccination.

Prevalence and genetic diversity of Parechovirus A in children with diarrhea in Beijing, China, 2017-2019

We analyzed the prevalence and genotypes of Parechovirus A (PeV-A) in children with diarrhea in Beijing, China, 2017-2019. A total of 1734 stool samples collected from children <5 years of age with diarrhea were tested for the presence of PeV-A. Viral RNA was detected by real-time RT-PCR, and then genotyped by nested RT-PCR. We detected PeV-A in 93 (5.4%, 93/1734) samples, of which 87 could be genotyped by amplification of either the complete or partial VP1 region or the VP3/VP1 junction region. The median age of PeV-A infected children was 10 months. Most PeV-A infections were observed between August and November, with a peak in September. Seven known genotypes of PeV-A1A, -A1B, -A3, -A4, -A6, -A8 and -A11 were detected and PeV-A1B was the most prevalent genotype. Coinfection with other diarrheal viruses was observed in 30.1% (28/93) of PeV-A positive samples. All strains of PeV-A1A, -A1B, -A4 and -A6 obtained in this study contained the arginine-glycine-aspartic (RGD) motif, while all strains of PeV-A3, -A8 and -A11 lacked it. This study revealed a high genetic diversity of PeV-A circulating in Beijing and PeV-A11 was reported for the first time in children with diarrhea in China.

Assessment of Rotavirus Infection in Hospitalized Children with Diarrhea

Background: Rotavirus (RV) is associated with diarrhea in children under 5 years old. It leads to severe dehydration. RV infection is the third cause of hospitalization and death in children under 5 years old. Objectives: This study aimed to assess the frequency of RV infection in hospitalized children under 5 years old with diarrhea during 2021-2022. Methods: In this cross-sectional observational study, a total of 190 stool samples from hospitalized children with diarrhea were collected in Mofid Children’s Hospital in Tehran from December 2020 to March 2021. RV infection was detected by an enzyme-linked immunosorbent assay (ELISA). Chi-square tests were performed to determine the difference in age and gender group, time, and symptoms. Results: The overall prevalence of RV infection was 28.5% and higher in boys (68.5%), children aged ≤ 12 months (44.4%), and children with mixed feeding (33.3%); it is more common in winter. Vomiting (79.6%), fever (87.03%), and non-exudative stool (88.8%) were observed in most children with RV, but there were no significant differences in children with and without RV. Conclusions: Due to the prevalence of RV among children under 5 years of age, establishing a national RV registration system and control programs, like vaccination, seems to be considered.

A Clinical Nursing Care Study on the Prevalence of Rotavirus Infection and Acute Diarrhea in Vaccinated Chinese Pediatric Population from 2019-2022

Purpose

To investigate the prevalence of rotavirus infection and acute diarrhea after immunization and further assess the quality of nursing care provided by the nurses to such patients.

Methods

A total of 432 children aged 3–36 months with acute diarrhea between February 2019 and March 2022 were enrolled, and rotavirus testing was performed within 24 h using a rotavirus enzyme immunoassay kit. Clinical characteristics were evaluated, and regression analysis was performed.

Results

Eighty vaccinated children (18.5%) were confirmed to have rotavirus infection out of 432 children. The prevalence of rotavirus positivity was the highest at 20–28 months (22 cases, 24.44%) and 11–19 months age group (27 cases, 22.50%). There is a significant association between rotavirus infection and hygiene score (p = 0.009). Based on the association with quality of nursing care, rotavirus infection was association with “appropriate care” (p = 0.001).

Conclusion

Rotavirus infection was strongly associated with poor hygiene score which may be due to the hygienic nature of the mother and her family. Nursing care assessments revealed a huge gap between nurses and the guardians, which reflects the behavior of Chinese nurses. Thus, an intervention is required by the policymakers for implementing effective strategies of quality nursing for the improvement of the pediatric patients with rotavirus gastroenteritis.

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.

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.

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.

High mortality from carbapenem-resistant Klebsiella pneumoniae bloodstream infection

In this study, it was evaluated clinical data of 107 patients with bloodstream infection (BSI) by Klebsiella pneumoniae and performed phenotypic and molecular analyzes in 50.5% (54/107) of the samples, those that showed a resistance profile to carbapenemics. The bla_KPC gene was present in 90.4% (49/54) of the samples, bla_NDM gene in one sample and, in 7.4% (4/54) of the samples, no carbapenemase gene was found. In the similarity analysis, it was found 4 main clones and 11 samples were not genetically related. The median age of the patients was 58 (40-70) years old and 60.7% (65/107) were male. When comparing two groups of patients with BSI due to K. pneumoniae with and without resistance to carbapenems, the variables ICU permanence, renal failure (IR), previous use of antimicrobials, Charlson's comorbidity index (ICCi), some invasive procedures and death showed a statistically significant difference (p < 0.05). And when relating death as a dependent variable, IR, liver failure and patients with BSI XDR or PDR, were predictors of increased mortality. Our study showed a higher mortality rate in patients with BSI due to carbapenem-resistant pneumonia with additional resistance or not to polymyxins.

Epidemiological characteristics and genetic diversity of norovirus infections among outpatient children with diarrhea under 5 years of age in Beijing, China, 2011-2018

Background

Human noroviruses are the leading cause of sporadic cases and outbreaks of viral acute gastroenteritis in all age groups worldwide.

Methods

Epidemiological data and fecal specimens were collected between January 2011 and December 2018 from 4911 children < 5 years of age with diarrhea in three districts of Beijing. From 2011 to 2013, One-Step Reverse Transcription Polymerase Chain Reaction (RT-PCR) was used to detect noroviruses, and from January 2014 to December 2018, norovirus GI and GII were screened using duplex quantitative real-time RT-PCR (qRT-PCR). One-Step RT-PCR and RT-seminested PCR were performed to amplify the RNA-dependent polymerase and capsid genes of noroviruses in positive sample. Amplified products were sequenced directly; norovirus was typed using the online Norovirus Genotyping Tool v2.0 and phylogenetic analyses were conducted using MEGA-X.

Results

From 2011 to 2018, noroviruses were detected in 16.5% of specimens from children with diarrhea. The highest prevalence was observed in children aged 12 to 23 months (22.4%, 319/1421), followed by children aged 6 to 11 months (17.6%, 253/1441). The highest prevalence of norovirus infections occurred in autumn followed by winter, spring, and summer. From 2011 to 2018, the most prevalent dual types (genotype and polymerase type) were GII.4 Sydney[P31] (51.6%, 239/463), followed by GII.3[P12] (24.0%, 111/463), GII.4 2006b[P4 2006b] (7.3%, 34/463), GII.2[P16] (5.0%, 23/463), GII.17[P17] (2.6%, 12/463) and GII.6[P7] (2.6%, 12/463). GII.4 2006b[P4 2006b] predominated in 2011 and 2012. GII.4 Sydney[P31] predominated from 2013 to 2018. In total, 15 genotypes, 15 P-types and 19 dual types were detected in this study, reflecting the genetic diversity.

Conclusions

There were significant epidemiological characteristics and genetic diversity among outpatient children with norovirus infections < 5 years of age in Beijing from 2011 to 2018. These characteristics differ from those of norovirus outbreaks in Beijing. The complete genome sequences of each genotype are needed to better understand norovirus evolutionary mechanisms.

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.

Role of rotavirus vaccination on G9P[8] rotavirus strain during a seasonal outbreak in Japan

Although two live oral rotavirus (RV) vaccines, Rotarix and RotaTeq, play a critical role toward reducing disease severity, hospitalization, and death rate in RV infections, regular monitoring of vaccine effectiveness (VE) is yet necessary because the segmented genome structure and reassortment capability of RVs pose considerable threats toward waning VE. In this study, we examined the VE by a test-negative study design against G9P[8]I2 strain during a seasonal outbreak in February-May, 2018, in an outpatient clinic in Kyoto Prefecture, Japan. It remains important because G9P[8]I2 strain remains partially heterotypic to these vaccines and predominating in post-vaccination era. During year-long surveillance, RV infections were detected only from February to May. During this outbreak, 33 (42.3%) children out of 78 with acute gastroenteritis (AGE) remained RV-positive, of which 29 (87.8%) children were infected with G9P[8]I2. Two immunochromatographic (IC) assay kits exhibited 100% sensitivity and specificity to detect G9P[8]I2 strain. Only 23.2% children were found to be vaccinated. Yet, significant VE 69.7% (95% CI: 2.5%-90.6%) was recognized against all RV strains that increased with disease severity. Similar significant VE 71.8% (95% CI: 1%-92%) was determined against G9P[8]I2 strain. The severity score remained substantially low in vaccinated children. Our data reveal that vaccine-preventable G9P[8]I2 strain yet may cause outbreak where vaccination coverage remains low. Thus, this study emphasizes the necessity of global introduction of RV-vaccines in national immunization programs of every country.

Group A rotavirus prevalence and genotypes among adult outpatients with diarrhea in Beijing, China, 2011-2018

Group A rotavirus (RVA) is one of the most common causes of severe diarrhea in children worldwide. However, RVA is also an important pathogen causing adult diarrhea, with higher infection rates in older patients. To provide evidence for rotavirus epidemic control and to inform vaccine development, we analyzed the molecular epidemiology of RVA among adult outpatients with diarrhea in Beijing from 2011 to 2018. Stool specimens were collected monthly from 14 districts. RVA was detected using enzyme-linked immunosorbent assay and real-time reverse-transcription polymerase chain reaction (RT-PCR). Genotyping of rotavirus was performed using multiplex semi-nested RT-PCR. Phylogenetic analysis was performed using maximum likelihood methods implemented in MEGA software (version 6.06). Logistic regression and chi-square tests were used to assess differences among age groups, districts, years, and genotype distributions. The prevalence of rotavirus was 10.16% (1310 of 12,893) among adult outpatients with diarrhea from 2011 to 2018 in Beijing. The highest prevalence (13.74%, 600 of 4367) was observed among those aged 41 to 65 years. November, December, and January had the highest positive detection rates. In 2011, G3P[8] and G9P[8] were the dominant genotypes. Starting from 2012, G9P[8] became the dominant genotype. Most G9 strains belonged to the G9-VI clade. Most P[8] strains belonged to the P[8]-III clade. RVA is a major cause of adult diarrhea in Beijing. Continuous molecular surveillance is needed, and transmission of rotavirus between children and adults should be investigated further.

Rotavirus gastroenteritis in Pakistan, 2018: updated disease burden

Objective

Rotavirus A (RVA) is a significant cause of severe diarrheal illness and one of the common causes of death in children under the age of five. This study was aimed at detecting the prevalence of RVA in Pakistan after rotavirus vaccines were introduced. Fecal samples were obtained from 813 children from different hospitals in Rawalpindi and Islamabad, Pakistan, from January 2018 to December 2018. To obtain additional information from the parents / guardians of the children, a standard questionnaire was used.

Results

Using an enzyme-linked immunosorbent assay kit (ELISA), rotavirus antigen was detected and ELISA positive samples were subjected to reverse transcription PCR (RT-PCR). The findings showed 22% prevalence of RVA in children with acute gastroenteritis (AGE) via ELISA and 21% prevalence via RT-PCR in children with AGE. There was no statistically significant difference between gender, age and RVA infections. The winter, spring and fall/autumn seasons were statistically significant for RVA prevalence.

Conclusion

The present study will provide post vaccine prevalence data for the health policy makers. The implementation of rotavirus vaccines, along with adequate nutrition for babies, clean water supply and maternal hygienic activities during infant feeding, is recommended. Furthermore, continuous surveillance is mandatory in the whole country to calculate the disease burden caused by RVA.

Genetic diversity and molecular epidemiological characterization of group A rotaviruses in raw sewage in Jinan by next generation sequencing

OBJECTIVE

To understand the genetic diversity and molecular epidemiology characteristics of group A Rotavirus (RVA) in domestic sewage through next generation sequencing (NGS), and to explore the feasibility and necessity of NGS method for RVA environmental surveillance.

METHODS

In this study, two sewage samples from Jinan each quarter in 2019 were selected for concentration, RNA extraction, and then RT-PCR reaction. The amplified positive products were subjected to NGS. Finally, the results were analyzed for diversity and phylogeny.

RESULTS

A total of 9 G-genotypes and 13 P-genotypes were detected. The Simpson diversity indices in autumn and winter were relatively high. Phylogenetic analysis showed that the dominant types G9 and P[8] were closely related to human-derived sequences.

CONCLUSIONS

This study proves that environmental surveillance as a means to understand the prevalence of RVA in the population is not only feasible but necessary. NGS based environmental surveillance greatly improves our understanding on RVA genetic diversity, and should be encouraged as a sensitive surveillance tool.

Effect of ambient temperatures on category C notifiable infectious diarrhea in China: An analysis of national surveillance data

BACKGROUND

Many studies have explored the association between meteorological factors and infectious diarrhea (ID) transmission but with inconsistent results, in particular the roles from temperatures. We aimed to explore the effects of temperatures on the transmission of category C ID, to identify its potential heterogeneity in different climate zones of China, and to provide scientific evidence to health authorities and local communities for necessary public health actions.

METHODS

Daily category C ID counts and meteorological variables were collected from 270 cities in China over the period of 2014-16. Distributed lag non-linear models (DLNMs) were applied in each city to obtain the city-specific temperature-disease associations, then a multivariate meta-analysis was implemented to pool the city-specific effects. Multivariate meta-regression was conducted to explore the potential effect modifiers. Attributable fraction was calculated for both low and high temperatures, defined as temperatures below the 5th percentile of temperature or above the 95th percentile of temperature.

RESULTS

A total of 2,715,544 category C ID cases were reported during the study period. Overall, a M-shaped curve relationship was observed between temperature and category C ID, with a peak at the 81st percentile of temperatures (RR = 1.723, 95% CI: 1.579-1.881) compared to 50th percentile of temperatures. The pooled associations were generally stronger at high temperatures compared to low ambient temperatures, and the attributable fraction due to heat was higher than cold. Latitude was identified as a possible effect modifier.

CONCLUSIONS

The overall positive pooled associations between temperature and category C ID in China suggest the increasing temperature could bring about more category C infectious diarrhea cases, which warrants further public health measurements.

Time series analysis of the relationship between diarrhea in children and Rota 2 vaccine in the Fanteakwa District of the eastern region of Ghana

BACKGROUND

Rotavirus is considered the main causal factor of severe gastroenteritis among infants and children globally. The association with severe rotavirus infection is mostly worse among the least developed countries, mainly due to inadequate access to medical care and poverty. This study was conducted to determine the seasonal effects in respect of diarrhea cases in children, the association between diarrhea cases and Rota2 vaccine in the Fanteakwa District of the Eastern Region of Ghana.

METHODS

The study compares monthly diarrhea cases against children vaccinated with Rota2 extracted from DHIMS2 spanning May 2012 to December 2017 in Fanteakwa District. A univariate association between diarrhea cases and children vaccinated with Rota 2 was conducted using the R-software version 3.4.4 with the use of forecast, tseries and TSAPred. Pearson Correlation coefficient was also computed between monthly diarrhea cases and Rota 2 as well as lagged values of Rota 2 and Diarrhea cases.

RESULTS

The study shows that February recorded the highest average number of diarrhea cases (172) over the period 2012 to 2017 with a standard deviation of 59. However, a one-way analysis of variance shows a significant difference amongst the monthly averages with an F-statistic of 0.042 and P-value of 0.064. It is observed that the correlations between each of the Rota2 doses and the lagged cases are positive, showing higher Rota2 doses a month ago ((Xt - 1),0.346 to 0.735), two months ago ((Xt - 2),0.383 to 0.746), three months ago ((Xt - 3), 0.330 to 0.737) and four months ago ((Xt - 4), 0.236 to 0.723) are associated with lower diarrhea cases. The results also show that an increase in the previous two month's Rota2 figures by 100 is associated with a significant decrease in the currently expected diarrhea cases by approximately 36.

CONCLUSION

Seasonal variations exist in the occurrence of diarrhea in children, with January recording the highest number of diarrhea cases (172). There is a relationship between episodes of diarrhea in children and Rota2 (p-value = 0.064); thus, the more children are vaccinated with Rota2, the less diarrhea cases are recorded. Diarrhea cases in Fanteakwa district are generally low, except 2013 and 2016 where the cases are higher than the rest of the other years.

Rotavirus genotype trends from 2013 to 2018 and vaccine effectiveness in southern Vietnam

OBJECTIVES

Rotavirus (RV) genotypes vary geographically, and this can affect vaccine effectiveness (VE). This study investigated the genotype distribution of RV and explored VE before introducing the RV vaccine to the national immunization programme in Vietnam.

METHODS

This hospital-based surveillance study was conducted at Children's Hospital 1, Ho Chi Minh City in 2013-2018. Stool samples and relevant data, including vaccination history, were collected from children aged <5 years who were hospitalized with gastroenteritis. RV was detected using enzyme immunoassays and then genotyped. Children aged ≥6 months were included in the VE analysis.

RESULTS

Overall, 5176 children were included in this study. RV was detected in 2421 children (46.8%). RV positivity decreased over the study period and was associated with age, seasonality, location and previous vaccination. Among 1105 RV-positive samples, G3P[8] was the most prevalent genotype (43.1%), followed by G8P[8] (19.7%), G1P[8] (12.9%) and G2P[4] (12.9%). Overall VE was 69.7% [95% confidence interval (CI) 53.3-80.6%] in fully vaccinated children and 58.6% (95% CI 44.1-69.4%) in children who had received at least one dose of RV vaccine. VE was highest for G3P[8] (95% CI 75.1-84.5%) and lowest for G2P[4] (95% CI 32.4-57.2%).

CONCLUSIONS

RV remains a major cause of acute gastroenteritis requiring hospitalization in southern Vietnam. The RV vaccine is effective, but its effectiveness varies with RV genotype.

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.

ASSESSMENT OF THE DEPENDENCE OF THE CLINICAL MANIFESTATION OF ACUTE GASTROENTERITIS CAUSED BY ROTAVIRUS ON ITS GENOTYPES

The leading cause of acute gastroenteritis (AGE) in children is rotavirus. In different countries, different rotavirus genotypes prevail and are associated with different severity of disease. The purpose of our study was to identify the distribution of rotavirus genotypes in Kyiv, Ukraine, and to determine the correlation between the genotypes and course of disease. Materials and methods. 978 children under 5 years of age were examined with АGE symptoms and not vaccinated against rotavirus. Determination of rotavirus antigen and genotype were performed using the immunoenzymatic assay and real-time RT-PCR. We assessed the demographics, clinical manifestations of AGE, the Vesikari scale AGE severity. Results. The G4P[8] genotype prevailed in Ukraine during 2014-2018. The G1P[8] was the second most common. G9P8 was the third, the fourth place was shared by G2P[4] and G3P[8]. Fever, as a manifestation, was more pronounced in G1P[8] and G3P[9]. The highest number of vomiting episodes per day occurred in the G1P[8] and G4P[8]-related cases. Maximum of diarrhea episodes per day was observed in genotypes G1P[8], G3P[8], G4P[8] and G9P[8]. Mucus and blood in stool were found in genotypes G3P[8] (1/33.33 %), G4P[8] – blood (1/2.27 %). The children with genotypes G1P[8] and G4P[8] had catarrhal symptoms. More cases of moderate and severe dehydration, occurred in the G4P[8]. The Vesikari scale analysis showed that only G1P[8] led to mild cases(3.57 %). The most widespread genotypes, G1P[8] and G4P[8], led to a moderate illness in 14.29 % and 13.56 % cases, respectively, and to a severe illness in 82.14 % and 86.44 % cases, respectively. Conclusions. G4P[8] was associated with the most severe disease due to more frequent and prolonged vomiting, febrile fever and bloody diarrhea. G1P[8] and G4P[8] were associated with catarrh.

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.

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

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

Rotavirus contamination of surface waters from the northwest of Argentina

Fecal pollution of water is a serious concern because it is associated with the transmission of pathogens. The aim of this study was to analyze the occurrence of group A rotavirus (RVA) in surface waters from the Arias-Arenales River in Salta, a northern city in Argentina, and to define possible sources of fecal viral pollution. A total of 116 water samples were analyzed and RVA was detected in 3.4% (95% CI: 0.1-7.0%), with concentrations ranging from 1.9 × 10⁵ to 3.8 × 10⁶ genome copies per liter. RVA strains were characterized as G1P[8], G4P[8] and G9P[8], which are common genotypes circulating in the local population. The Arias-Arenales River presented unusual and sporadic contamination by RVA, originated from stormwater discharges and a variety of non-identified sources, and support the essential need of viral indicators for enhanced monitoring of water quality.

Prevalence of Eleven Infectious Viruses Causing Diarrhea in Korea

Rotavirus and norovirus are well-known causes of viral infectious diarrhea. There are few reports on diarrhea caused by other viruses in Korea, although cases of gastroenteritis attributable to other viruses are increasing worldwide. The aims of this study were to detect various causes of viral diarrhea and to investigate their prevalence. A total of 801 fecal specimens submitted to a clinical microbiology laboratory for the detection of diarrheal viruses were included. We sought to detect rotavirus A/B/C, adenovirus, astrovirus, norovirus GI/GII, sapovirus, Aichi virus, human parechovirus, enterovirus, human cosavirus, human bocavirus, and Saffold virus using multiplex reverse transcription polymerase chain reaction (RT-PCR). At least one diarrheal virus was detected in 223 (27.8%) fecal specimens. Among them, two viruses were detected in 11 specimens. Rotavirus A was most common (17.1%; N = 137), followed by norovirus GII (5.0%; N = 40), enterovirus (4.2%; N = 34), adenovirus (1.0%; N = 8), astrovirus (1.0%; N = 8), human parechovirus (0.6%; N = 5), and human bocavirus (0.2%; N = 2). Rotaviruses B and C, norovirus GI, sapovirus, Aichi virus, human cosavirus, and Saffold virus were not detected. We confirmed that various diarrheal viruses can be detected in fecal specimens. We must consider the possibility of viruses other than rotavirus and norovirus being present in cases of diarrhea.

Validation of a Laboratory-Developed Triplex Molecular Assay for Simultaneous Detection of Gastrointestinal Adenovirus and Rotavirus in Stool Specimens

Enteric viral pathogens causing gastroenteritis include adenovirus and rotavirus, among others. Rotavirus is the leading cause of severe diarrhea in infants and young children worldwide. Among the adenoviruses known to cause gastroenteritis are those of species F (serotypes 40, 41). Here, we describe the development and validation of a laboratory-developed gastrointestinal triplex rRT-PCR (triplex) assay that targets adenovirus and rotavirus. Stool specimens were tested from patients across Ontario. Specimens were previously tested for adenovirus and/or rotavirus by electron microscopy (EM) or immunochromatographic test (ICT). Triplex sensitivity, specificity, positive and negative predictive values compared to Seegene assay (a commercial assay used here as the standard reference method) were 100%, 97.8%, 86.0%, 100% for adenovirus, and 99.1%, 98.4%, 96.3%. 99.6% for rotavirus, respectively. The triplex assay had a 95.2% and 97.3% overall percent agreements (OPAs) when compared to EM for adenovirus or rotavirus detection, respectively, and an OPA of 90.9% when compared to rotavirus ICT for rotavirus detection. Triplex assay exhibited similar performance to the Seegene assay for both adenovirus and rotavirus and detected more adenovirus and rotavirus than traditional testing methods. The high performance along with lower cost and reduced turnaround time makes the triplex assay a desirable testing method for a clinical microbiology laboratory.

Distribution of rotavirus genotypes in Japan from 2015 to 2018: Diversity in genotypes before and after introduction of rotavirus vaccines

BACKGROUND

Diversity in group A rotavirus (RVA) strains after introduction of RV-vaccines remains an emerging concern worldwide. In this study, we investigated the prevalence and distribution of RVA genotypes in Japanese children with acute gastroenteritis (AGE) from 2015 to 2018. In addition, a comparison of the genotypes in pre-vaccination (2006-2012) and post-vaccination (2012-2018) periods was conducted to understand the impact of these vaccines on genotype distribution.

METHODS

Fecal samples were collected regularly from outpatient clinics in six localities: Hokkaido, Tokyo, Shizuoka, Osaka, Kyoto, and Saga. RVA were screened and genotyped by RT-PCR and sequence-based genotyping.

RESULTS

During the period 2015-2018, RVA was detected in 307 (19.7%) samples out of 1557 specimens: 29.9% (95% CI: 25.8% to 34.3%), 17.9% (95% CI: 14.7% to 21.5%), and 13% (95% CI: 10.3% to 16.0%) were detected RVA-positive in 2015-2016, 2016-2017 and 2017-2018, respectively. The average detection of RVA in pre-vaccination (2006-2012) and post-vaccination (2012-2018) era remained almost similar (18%-20%). The G2P[4]I2 (52.1%, 95% CI: 43.5%-60.6%) remained the most common genotype in 2015-2016, whereas G8P[8]I2 (55.9%, 95% CI: 45.2%-66.2%) dominated in 2016-2017. In 2017-2018, G9P[8]I2 (42.0%, 95% CI: 30.5%-53.9%) prevailed, followed by G9P[8]I1 (23.0%, 95% CI: 14.0%-34.2%). The detection rate of some common genotypes of pre-vaccination era like G1P[8] and G3P[8] has been reduced after introduction of RV-vaccine, whereas genotypes that were sporadic before the introduction of vaccines like G2P[4], G2P[8], G9P[8] and G8P[8] were emerged/reemerged in post-vaccination period.

CONCLUSIONS

Our study presented the diversity in circulating RVA genotypes in Japan before and after introduction of RV-vaccines. Sudden emergence of DS-1-like (I2) unusual strains in post-vaccination era remains alarming. Continuous monitoring of RVA genotypes is therefore indispensable to refine future vaccine strategy.

Characterization of a G9 group A rotavirus reassortant strain detected in Jinzhou, China, in 2018-2019

A novel rotavirus A (RVA) strain (JZ) was detected in RVA-positive stool specimens from three pediatric patients in Jinzhou, Liaoning Province, in 2018-2019. The electrophoresis pattern of the JZ strain showed a long electropherotype. The genomic constellation G9-P[8]-I1-R1-C1-M1-A1-N1-T1-E2-H1 was detected, suggesting that a new inter-genogroup reassortment had occurred. Whole-genome sequencing showed that the JZ isolates were identical to each other. Phylogenetic analysis revealed that VP7 and VP4 clustered in lineages G9-VI and P[8]-3, respectively. JZ strain-specific amino acid substitutions were detected in VP7, VP4 and NSP4. This study provides information on the epidemiology and characteristics of G9 strains circulating in China.

(Patho-)Physiology of Na+/H+ Exchangers (NHEs) in the Digestive System

Na⁺/H⁺ exchangers (NHEs) are expressed in virtually all human tissues and organs. Two major tasks of those NHE isoforms that are located in plasma membranes are cell volume control by Na⁺-uptake and cellular pH regulation by H⁺-extrusion. Several NHEs, particularly NHE 1–4 and 8, are involved in the pathogenesis of diseases of the digestive system such as inflammatory bowel disease (ulcerative colitis, Crohn’s disease) and gastric and colorectal tumorigenesis. In the present review, we describe the physiological purposes, possible malfunctions and pathophysiological effects of the different NHE isoforms along the alimentary canal from esophagus to colon, including pancreas, liver and gallbladder. Particular attention is paid to the functions of NHEs in injury repair and to the role of NHE1 in Barrett’s esophagus. The impact of NHEs on gut microbiota and intestinal mucosal integrity is also dealt with. As the hitherto existing findings are not always consistent, sometimes even controversial, they are compared and critically discussed.

Fecal Source Tracking in A Wastewater Treatment and Reclamation System Using Multiple Waterborne Gastroenteritis Viruses

Gastroenteritis viruses in wastewater reclamation systems can pose a major threat to public health. In this study, multiple gastroenteritis viruses were detected from wastewater to estimate the viral contamination sources in a wastewater treatment and reclamation system installed in a suburb of Xi'an city, China. Reverse transcription plus nested or semi-nested PCR, followed by sequencing and phylogenetic analysis, were used for detection and genotyping of noroviruses and rotaviruses. As a result, 91.7% (22/24) of raw sewage samples, 70.8% (17/24) of the wastewater samples treated by anaerobic/anoxic/oxic (A²O) process and 62.5% (15/24) of lake water samples were positive for at least one of target gastroenteritis viruses while all samples collected from membrane bioreactor effluent after free chlorine disinfection were negative. Sequence analyses of the PCR products revealed that epidemiologically minor strains of norovirus GI (GI/14) and GII (GII/13) were frequently detected in the system. Considering virus concentration in the disinfected MBR effluent which is used as the source of lake water is below the detection limit, these results indicate that artificial lake may be contaminated from sources other than the wastewater reclamation system, which may include aerosols, and there is a possible norovirus infection risk by exposure through reclaimed water usage and by onshore winds transporting aerosols containing norovirus.

Molecular characterization of human group A rotavirus genotypes circulating in Rawalpindi, Islamabad, Pakistan during 2015-2016

Group A rotaviruses (RVA) are one of the major causes of acute gastroenteritis (AGE) in young children worldwide. Owing to lack of proper surveillance programs and health facilities, developing countries of Asia and Africa carry a disproportionately heavy share of the RVA disease burden. The aim of this hospital-based study was to investigate the circulation of RVA genotypes in Rawalpindi and Islamabad, Pakistan in 2015 and 2016, prior to the implementation of RVA vaccine. 639 faecal samples collected from children under 10 years of age hospitalized with AGE were tested for RVA antigen by ELISA. Among 171 ELISA positive samples, 143 were successfully screened for RT-PCR and sequencing. The prevalence of RVA was found to be 26.8% with the highest frequency (34.9%) found among children of age group 6-11 months. The most predominant circulating genotypes were G3P[8] (22.4%) followed by G12P[6] (20.3%), G2P[4] (12.6%), G1P[8] (11.9%), G9P[6] (11.9%), G3P[4] (9.1%), G1P[6] (4.2%), G9P[8] (4.2%), and G3P[6] (0.7%). A single mixed genotype G1G3P[8] was also detected. The findings of this study provide baseline data, that will help to assess if future vaccination campaigns using currently available RVA vaccine will reduce RVA disease burden and instigate evolutionary changes in the overall RVA biology. The high prevalence of RVA infections in Pakistan require to improve and strengthen the surveillance and monitoring system for RVA. This will provide useful information for health authorities in planning public health care strategies to mitigate the disease burden caused by RVA.

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.

Effectiveness of Lanzhou lamb rotavirus vaccine in preventing gastroenteritis among children younger than 5 years of age

BACKGROUND

Lanzhou Lamb rotavirus (LLR) vaccine was licensed in China in 2000. It was the only vaccine available in private market before 2018. However, the data about the post-marketing effectiveness is very limited. To assess the vaccine effectiveness (VE), we conducted a case-control study based on the hospital surveillance system in Beijing from 2015 to 2017.

METHODS

Seven hospitals located in seven districts in Beijing, from October 1, 2015, to March 31, 2017, were included. The VE of LLR vaccine was assessed in laboratory-confirmed rotavirus infection among children younger than five years old through a case-control design, using rotavirus-negative cases as controls. LLR vaccination was documented from a vaccination registry. VE was estimated adjusting for age group, gender, study site, the month of illness onset and interval days between illness onset to sampling through a logistic regression model.

RESULTS

A total of 598 cases and 1766 controls were included in this study. The vaccine average coverage rate during 2015-2017 among children younger than five years old was 10.8% in Beijing. The adjusted VE for LLR vaccine of 1 dose versus 0 dose was 34.9% (95%CI, 5.3-55.3). We also obtained the adjusted VE of 87.7% (95%CI, 32.7-97.8) for patients with the severity score ≥11, 36.2% (95%CI, 4.7-57.3) for children of 2-35 months age group and 40.8% (95%CI, 7.8-61.9) against G9 rotavirus infection. Vaccinated cases were less likely to have watery stool (OR = 0.42) and have diarrhea longer than 5 days (OR = 0.47) than unvaccinated cases.

DISCUSSION

LLR vaccine conferred protection against rotavirus disease. Children who were vaccinated presented with less severe clinical manifestations. An immunization schedule of receiving all three doses in the first year should be preferred.