Rotavirus disease and genotype diversity in older children and adults in Australia

Effect of rotavirus vaccination on the burden of rotavirus disease and associated antibiotic use in India: A dynamic agent-based simulation analysis

BACKGROUND

Rotavirus is a leading cause of diarrhea in infants and young children in many low- and middle-income countries. India launched a childhood immunization program for rotavirus in 2016, starting with four states and expanding it to cover all states by 2019. The objective of this study was to estimate the effects of the rotavirus vaccination program in India on disease burden and antibiotic misuse.

METHODS

We built a dynamic agent-based model of rotavirus progression in children under five within each district in India. Simulations were run for various scenarios of vaccination coverage in the context of India's Universal Immunization Programme. Population data were obtained from the National Family Household Surveys and used to calibrate the models. Disease parameters were obtained from published studies. We estimated past and projected future reduction of disease burden and antibiotic misuse due to full vaccination nationwide, by state, and by wealth quintile.

RESULTS

We estimate that rotavirus vaccination in India has reduced the prevalence of rotavirus cases by 33.7% (prediction interval: 30.7-36.0%), total antibiotic misuse due to rotavirus by 21.8% (18.6-25.1%), and total deaths due to rotavirus by 38.3% (31.3-44.4%) for children under five. We estimate total antibiotic misuse due to rotavirus infection to be 7.6% (7.5-7.9%) of total antibiotic consumption in this demographic versus 9.6% (9.4-9.9%) in the absence of vaccination. We project rotaviral prevalence to drop to below one case for every 100,000 individuals in those below five if vaccination coverage is increased by 50.3% (45.2-58.5%) to 68.1% (63.1-76.4) nationwide.

CONCLUSION

Universal coverage of childhood rotavirus vaccination can substantially reduce inappropriate antibiotic use in India.

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 enteric viruses responsible of gastroenteritis in urban and rural Burkina Faso

BACKGROUND

Viral gastrointestinal infections remain a major public health concern in developing countries. In Burkina Faso, there are very limited updated data on the circulating viruses and their genetic diversity.

OBJECTIVES

This study investigates the detection rates and characteristics of rotavirus A (RVA), norovirus (NoV), sapovirus (SaV) and human astrovirus (HAstV) in patients of all ages with acute gastrointestinal infection in urban and rural areas.

STUDY DESIGN & METHODS

From 2018 to 2021, stool samples from 1,295 patients with acute gastroenteritis were collected and screened for RVA, NoV, SaV and HAstV. Genotyping and phylogenetic analyses were performed on a subset of samples.

RESULTS

At least one virus was detected in 34.1% of samples. NoV and SaV were predominant with detection rates of respectively 10.5 and 8.8%. We identified rare genotypes of NoV GII, RVA and HAstV, recombinant HAstV strains and a potential zoonotic RVA transmission event.

CONCLUSIONS

We give an up-to-date epidemiological picture of enteric viruses in Burkina Faso, showing a decrease in prevalence but a high diversity of circulating strains. However, viral gastroenteritis remains a public health burden, particularly in pediatric settings. Our data advocate for the implementation of routine viral surveillance and updated management algorithms for diarrheal disease.

Risk Factors of Convulsions in Children With Rotavirus Gastroenteritis and Construction of a Nomogram Prediction Model

OBJECTIVE

This study aims to investigate and analyze the risk factors of convulsions in children with rotavirus gastroenteritis and to construct a nomogram prediction model.

METHODS

A retrospective analysis was performed on 940 cases of pediatric patients with rotavirus gastroenteritis treated in our hospital from December 2017 to December 2022. Based on whether convulsions occurred during hospitalization, patients were divided into the convulsion group (n = 135) and the convulsion-free group (n = 805). Clinical information of patients in both groups was collected, logistic regression analysis was carried out to analyze the convulsion risk factors pertaining to children with rotavirus gastroenteritis, and a nomogram prediction model was constructed.

RESULTS

The univariate analysis revealed that fever, frequency of diarrhea, white blood cell count, blood calcium level, blood glucose level, CO 2 CP, creatine kinase myocardial band (CK-MB), and blood pH value were all factors that display statistically significant differences at the level of P = 0.05. Then, logistic regression analysis was carried out, taking the occurrence of such convulsions as the dependent variable and the aforementioned factors as independent variables. The results show that fever, frequency of diarrhea, blood calcium, CO 2 CP, and CK-MB were the independent risk factors ( P < 0.05), whereas the area under the receiver operating characteristic curve (area under the curve) of the constructed nomogram prediction model based on these factors was 0.842 (95% confidence interval, 0.821-0.914).

CONCLUSIONS

Frequency of diarrhea, blood calcium, CO 2 CP, and CK-MB are independent risk factors for the occurrence of convulsions in children with rotavirus gastroenteritis. The nomogram prediction model constructed based on these risk factors provides guidance and value in effectively preventing and controlling convulsions in children with rotavirus gastroenteritis.

Surveillance of human Group A rotavirus in Ningxia, China (2015-2021): Emergence and prevalence of G9P[8]-E2 and G3P[8]-E2 genotypes

BACKGROUND

Group A rotaviruses (RVA) are the primary pathogens of acute gastroenteritis. Currently, two live attenuated RVA vaccines, LLR and RotaTeq, have been introduced into mainland China but are not included in the national immunization program. Because of the unknown genetic evolution of group A rotavirus in an all-age population in Ningxia, China, we monitored the epidemiological characteristics and circulating genotypes of RVA as a reference for developing vaccine strategies.

METHODS

We conducted seven years of consecutive surveillance of RVA based on stool samples from patients with acute gastroenteritis in sentinel hospitals in Ningxia, China, from 2015 to 2021. Reverse transcription quantitative polymerase chain reaction(RT-qPCR) was used to detect RVA in stool samples. Genotyping and phylogenetic analysis of VP7, VP4 and NSP4 genes were performed by reverse transcription-polymerase chain reaction(RT-PCR) and nucleotide sequence determination.

RESULTS

RVA was detected in 16.58% (1436/8662) of 8662 stool samples. The positive rates were 7.17% (201/2805) and 21.09% (1235/5857) in adults and children, respectively. The most affected age group was infants and children aged 12-23 months, with a positive rate of 29.53% (p < 0.05). A significant winter/spring seasonality was observed. 23.29% positive rate in 2020 was the highest in 7 years (p < 0.05). The region with the highest positive rate in the adult group was Yinchuan, and the children's group was Guyuan. A total of 9 genotype combinations were found to be distributed in Ningxia. The dominant genotype combinations in this region gradually changed from G9P[8]-E1, G3P[8]-E1, G1P[8]-E1 to G9P[8]-E1, G9P[8]-E2, and G3P[8]-E2 during these seven years. Rare strains (e.g., G9P[4]-E1, G3P[9]-E3 and G1P[8]-E2) were occasionally detected during the study.

CONCLUSIONS

During the study period, changes in the significant RVA circulating genotype combinations and the emergence of reassortment strains were observed, particularly the emergence and prevalence of G9P[8]-E2, G3P[8]-E2 reassortants in the region. These results indicate the importance of continuous monitoring of the molecular evolution and recombination characteristics of RVA, and should not be limited to G/P genotyping but should consider multi-gene fragment co-analysis and whole genome sequencing.

Comparative whole genome analysis reveals re-emergence of human Wa-like and DS-1-like G3 rotaviruses after Rotarix vaccine introduction in Malawi

G3 rotaviruses rank among the most common rotavirus strains worldwide in humans and animals. However, despite a robust long-term rotavirus surveillance system from 1997 at Queen Elizabeth Central Hospital in Blantyre, Malawi, these strains were only detected from 1997 to 1999 and then disappeared and re-emerged in 2017, 5 years after the introduction of the Rotarix rotavirus vaccine. Here, we analysed representative twenty-seven whole genome sequences (G3P[4], n = 20; G3P[6], n = 1; and G3P[8], n = 6) randomly selected each month between November 2017 and August 2019 to understand how G3 strains re-emerged in Malawi. We found four genotype constellations that were associated with the emergent G3 strains and co-circulated in Malawi post-Rotarix vaccine introduction: G3P[4] and G3P[6] strains with the DS-1-like genetic backbone genes (G3-P[4]-I2-R2-C2-M2-A2-N2-T2-E2-H2 and G3-P[6]-I2-R2-C2-M2-A2-N2-T2-E2-H2), G3P[8] strains with the Wa-like genetic backbone genes (G3-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1), and reassortant G3P[4] strains consisting of the DS-1-like genetic backbone genes and a Wa-like NSP2 (N1) gene (G3-P[4]-I2-R2-C2-M2-A2-N1-T2-E2-H2). Time-resolved phylogenetic trees demonstrated that the most recent common ancestor for each ribonucleic acid (RNA) segment of the emergent G3 strains was between 1996 and 2012, possibly through introductions from outside the country due to the limited genetic similarity with G3 strains which circulated before their disappearance in the late 1990s. Further genomic analysis revealed that the reassortant DS-1-like G3P[4] strains acquired a Wa-like NSP2 genome segment (N1 genotype) through intergenogroup reassortment; an artiodactyl-like VP3 through intergenogroup interspecies reassortment; and VP6, NSP1, and NSP4 segments through intragenogroup reassortment likely before importation into Malawi. Additionally, the emergent G3 strains contain amino acid substitutions within the antigenic regions of the VP4 proteins which could potentially impact the binding of rotavirus vaccine-induced antibodies. Altogether, our findings show that multiple strains with either Wa-like or DS-1-like genotype constellations have driven the re-emergence of G3 strains. The findings also highlight the role of human mobility and genome reassortment events in the cross-border dissemination and evolution of rotavirus strains in Malawi necessitating the need for long-term genomic surveillance of rotavirus in high disease-burden settings to inform disease prevention and control.

14th International dsRNA Virus Symposium, Banff, Alberta, Canada, 10-14 October 2022

This triennial International dsRNA Virus Symposium covered original data which have accrued during the most recent five years. In detail, the genomic diversity of these viruses continued to be explored; various structure-function studies were carried out using reverse genetics and biophysical techniques; intestinal organoids proved to be very suitable for special pathogenesis studies; and the potential of next generation rotavirus vaccines including use of rotavirus recombinants as vectored vaccine candidates was explored. 'Non-lytic release of enteric viruses in cloaked vesicles' was the topic of the keynote lecture by Nihal Altan-Bonnet, NIH, Bethesda, USA. The Jean Cohen lecturer of this meeting was Polly Roy, London School of Hygiene and Tropical Medicine, who spoke on aspects of the replication cycle of bluetongue viruses, and how some of the data are similar to details of rotavirus replication.

Indirect impact of rotavirus vaccination on viral causes of acute gastroenteritis in the elderly

BACKGROUND

Rotavirus is considered a childhood infection causing acute gastroenteritis however, it also causes disease in adults which may be underestimated due to less frequent testing in this age-group.

OBJECTIVES

To determine if paediatric rotavirus vaccination, introduced into Ireland in December 2016, affected the viral aetiology in those aged ≥65 yrs presenting with gastroenteritis in the pre- and post-vaccination years. Additionally, rotavirus genotypes in this age-group will be described.

METHODS

Faecal samples from 2015 to 2019 for the investigation of gastroenteritis were tested by real-time (RT-) PCR for norovirus, adenovirus, rotavirus, Rotarix, astrovirus and sapovirus. Rotaviruses were genotyped by multiplex real-time RT-PCR or hemi-nested RT-PCR and a proportion confirmed by sequencing.

RESULTS

22,593 samples from adults aged ≥65 yrs were tested and 2566 (11 %) had ≥1 virus detected. Of 2566 positive samples, norovirus was detected in 82 %, rotavirus 9 %, sapovirus 6 %, astrovirus 3 % and adenovirus 1 %. Rotavirus and norovirus infections decreased between pre and post-vaccine year groups p < 0.001, whereas sapovirus, astrovirus and adenovirus remained unchanged. Between 2015-16 and 2018-19, G2P[4] increased and G4P[8] decreased, p < 0.001. In 2015-2019 there were 37 rotavirus outbreaks. Five geriatric outbreaks were genotyped and caused by G4P[8] (n = 1), G1P[8] (n = 1), G2P[4] (n = 2) and G12P[8] (n = 1).

CONCLUSION

Rotavirus causes acute gastroenteritis in older people. Paediatric vaccination may have contributed to a decline in infections in the elderly; nevertheless, rotavirus continued to circulate in older people following vaccine introduction. Genotype distribution changed between the pre- and post-vaccine era however genotypes in outbreak and endemic settings were comparable.