Rotavirus, Norovirus and Astrovirus in Children Aged 0 - 5 Years: Evolution of Prevalence over 10 Years (2013-2023) Following the Introduction of Rotavirus Vaccines in Burkina Faso

Rotaviruses, noroviruses, and astroviruses are responsible for gastroenteritis in children under 5 years old. The objective of our study was to estimate the evolution of prevalence of rotavirus, norovirus and astrovirus infections in children aged 0 to 5 years with gastroenteritis, after the introduction of rotavirus vaccines in Burkina Faso. This cross-sectional study was conducted between January and December 2023, collecting 100 stool samples from children with gastroenteritis at Saint Camille Hospital in Ouagadougou and the Charles De Gaulle University Paediatric Hospital. Noroviruses and astroviruses were detected using multiplex real-time PCR with a Sacace biotechnology detection kit. Data analysis was performed with Stata statistical software, version 16.0. The prevalence of norovirus infections was 14% and astrovirus infections were 9%. Rotavirus infections were found at prevalence of 15%. The age group most affected by norovirus and astrovirus infections was 0 - 12 months, with respective prevalence rates of 73.34% and 55.56%. The most frequently observed clinical signs in children infected with astrovirus were fever (77.78%), diarrhea (55.56%), and vomiting (44.44%). The introduction of rotavirus vaccines has reduced rotavirus-related infections. However, this has not significantly impacted the prevalence of norovirus and astrovirus infections in Burkina Faso.

Effectiveness of rotavirus vaccines against rotavirus infection and hospitalization in Latin America: systematic review and metaanalysis

Background:Rotavirus was the leading cause of childhood diarrhoea-related hospitalisations and death before the introduction of rotavirus vaccines.Methods:We describe the effectiveness of rotavirus vaccines to prevent rotavirus infections and hospitalizations and the main rotavirus strains circulating before and after vaccine introduction through a systematic review and meta-analysis of studies published between 1990 and 2014.203 studies were included to estimate the proportion of infections due to rotavirus and 10 to assess the impact of the vaccines.41 of 46 studies in the post-vaccination period were used for meta-analysis of genotypes,20 to calculate VE against infection,eight for VE against hospitalisation and seven for VE against severe rotavirus-diarrhoea.Results:24.3%(95%CI 22.1–26.5)and 16.1%(95%CI 13.2–19.3)of cases of diarrhoea were due to rotavirus before and after vaccine introduction,respectively.The most prevalent G types after vaccine introduction were G2(51.6%,95%CI 38–65),G9(14.5%,95%CI 7–23)and G1(14.2%,95%CI 7–23);while the most prevalent P types were P[4](54.1%,95%CI 41–67)and P[8](33%,95%CI 22–46).G2P[4]was the most frequent genotype combination after vaccine introduction.Effectiveness was 53%(95%CI 46–60)against infection,73%(95%CI,66–78)against hospitalisation and 74%(95%CI,68.0–78.0)against severe diarrhoea.Reductions in hospitalisations and mortality due to diarrhoea were observed in countries that adopted universal rotavirus vaccination.Conclusions:Rotavirus vaccines are effective in preventing rotavirus-diarrhoea in children in Latin America.The vaccines were associated with changes in genotype distribution.

Molecular-Genetic Characterization of Human Rotavirus A Strains Circulating in Moscow, Russia(2009–2014)

Enteric viruses are the most common cause of acute gastroenteritis （AGE） in young children and a significant public health problem globally. Hospital admissions of children under 5 years of age with diarrhea are primarily associated with group A rotavirus （RVA） infection. In this retrospective study, the population structure of viruses linked to AGE etiology in young children hospitalized with AGE in Moscow was evaluated, and molecular characterization of RYA strains was performed. Fecal specimens were collected from children under 5 years old hospitalized with AGE between 2009 and 2014 in Moscow, Russia. Multiplex real-time reverse transcription PCR was used to detect enteric viruses and for G/[P]-genotyping of isolated RVAs. Sequencing of RVA VP7 and VP4 cDNA fragments was used to validate the data obtained by PCR- genotyping. The main causes for hospitalization of children with AGE were RVA （40.1%）, followed by noroviruses （11.4%）, while adenoviruses, astroviruses, sapoviruses, enteroviruses, and orthoreoviruses were detected in 4.7%, 1.9%, 1.4%, 1.2%, and 0.2% of samples tested, respectively. Nosocomial infections, predominantly associated with RVAs and noroviruses, were detected in 24.8% of cases and occurred significantly more frequently in younger infants. The predominant RVA genotype was G4P[8], detected in 38.7% of RVA-positive cases, whereas genotypes G1P[8], G9P[8], G3P[8], and G2P[4] were found in 11.8%, 6.6%, 4.2%, and 3.3% of cases, respectively. Together, the presence of circulating RVA strains with rare VP7 and VP4 gene variants （G6 and P[9]） highlights the need to conduct continuous epidemiological monitoring of RVA infection.

Genotype analysis of rotaviruses isolated from children during a phase III clinical trial with the hexavalent rotavirus vaccine in China

The oral hexavalent live human-bovine reassortant rotavirus vaccine(RV6)developed by Wuhan Institute of Biological Products Co.,Ltd(WIBP)has finished a randomized,placebo-controlled phase III clinical trial in four provinces of China in 2021.The trail demonstrated that RV6 has a high vaccine efficacy against the prevalent strains and is safe for use in infants.During the phase III clinical trial(2019–2021),200 rotavirus-positive fecal samples from children with RV gastroenteritis(RVGE)were further studied.Using reverse transcription-polymerase chain reaction and high-throughput sequencing,VP7 and VP4 sequences were obtained and their genetic characteristics,as well as the differences in antigenic epitopes of VP7,were analyzed in detail.Seven rotavirus genotypes were identified.The predominant rotavirus genotype was G9P[8](77.0%),followed by prevalent strains G8P[8](8.0%),G3P[8](3.5%),G3P[9](1.5%),G1P[8](1.0%),G2P[4](1.0%),and G4P[6](1.0%).The amino acid sequence identities of G1,G2,G3,G4,G8,and G9 genotypes of isolates compared to the vaccine strains were 98.8%,98.2%–99.7%,88.4%–99.4%,98.2%,94.2%–100%,and 93.9%–100%,respectively.Notably,the vaccine strains exhibited high similarity in amino acid sequence,with only minor differences in antigenic epitopes compared to the Chinese endemic strains.This supports the potential application of the vaccine in preventing diseases caused by rotaviruses.