Whole-genome analysis of human group A rotaviruses in 1980s Japan and evolutionary assessment of global Wa-like strains across half a century.

Historically, the Wa-like strains of human group A rotavirus (RVA) have been major causes of gastroenteritis. However, since the 2010s, the circulation of non-Wa-like strains has been increasingly reported, indicating a shift in the molecular epidemiology of RVA. Although understanding RVA evolution requires the analysis of both current and historical strains, comprehensive pre-1980's sequencing data are scarce globally. We determined the whole-genome sequences of representative strains from six RVA gastroenteritis outbreaks observed at an infant home in Sapporo, Japan, between 1981 and 1989. These outbreaks were mainly caused by G1 or G3 Wa-like strains, resembling strains from the United States in the 1970s-1980s and from Malawi in the 1990s. Phylogenetic analysis of these infant home strains, together with Wa-like strains collected worldwide from the 1970s to 2020, revealed a notable trend: pre-2010 strains diverged into multiple lineages in many genomic segments, whereas post-2010 strains tended to converge into a single lineage. However, Bayesian skyline plot indicated near-constant effective population sizes from the 1970s to 2020, and selection pressure analysis identified positive selection only at amino acid 75 of NSP2. These results suggest that evidence supporting the influence of rotavirus vaccines, introduced globally since 2006, on Wa-like RVA molecular evolution is lacking at present, and phylogenetic analysis may simply reflect natural fluctuations in RVA molecular evolution. Evaluating the long-term impact of RV vaccines on the molecular evolution of RVA requires sustained surveillance.

Epidemiology of norovirus infection in Nigeria: a systematic review and meta-analysis.

Human norovirus (HuNoV) is responsible for most cases of gastroenteritis worldwide, but information about the prevalence and diversity of HuNoV infections in lower-income settings is lacking. In order to provide more information about the burden and distribution of norovirus in Nigeria, we systematically reviewed original published research articles on the prevalence of HuNoV in Nigeria by accessing databases, including PubMed, Web of Science, ScienceDirect, Google Scholar, and African Journals Online (AJOL). The protocol for the review was registered on PROSPERO (registration number CRD42022308857). Thirteen relevant articles were included in the review, and 10 of them were used for meta-analysis. The pooled prevalence of HuNoV-associated gastroenteritis among children below 5 years of age in Nigeria, determined using the random-effects model, was 10.9% (95% CI, 6.7-16.7%). Among children below the age of 5 presenting with HuNoV infections, the highest prevalence was in children ≤2 years old (n = 127, 83%). The prevalence of HuNoV infections was seen to decrease with increasing age. In addition, HuNoV was detected in asymptomatic food handlers, bats, and seafoods. A total of 85 sequences of HuNoV isolates from Nigeria have been determined, and based on those sequences, the most prevalent norovirus genogroup was GII (84%). Genotypes GII.4 and GI.3 were the most frequently identified genotypes, with GII.4 constituting 46% of all of the HuNoVs identified in Nigeria. These results suggest a risk associated with cocirculation of emerging variants with known genotypes because of their recombination potential. Larger molecular epidemiological studies are still needed to fully understand the extent and pattern of circulation of HuNoVs in Nigeria.

Fecal leukocyte frequency in children with acute viral gastroenteritis: a single-center experience.

OBJECTIVE: Our objective was to determine the frequency of rotavirus, adenovirus, and rota-adenovirus co-infections and investigate the fecal leukocyte rate associated with these infections in patients with gastroenteritis. METHODS: This is a retrospective study. We identified patients who were admitted to the pediatric emergency department with acute gastroenteritis and had their stool samples tested for rotavirus and/or adenovirus antigens. Among them, we determined the individuals who underwent stool microscopy tests on the same day and recorded their results. RESULTS: A total of 1,577 patients who underwent testing for rotavirus and/or adenovirus antigens in their stool samples were identified. Among these patients, 583 individuals had concurrent fecal microscopy results. The prevalence of solely rotavirus antigen positivity was 16.4%, solely adenovirus antigen positivity was 2.9%, and rota-adenovirus co-infections were detected in 1.8% of the children. The fecal leukocyte rates in children infected with rotavirus, adenovirus, and rota-adenovirus co-infections were 4.8, 13.3, and 88.9%, respectively. CONCLUSION: The presence of fecal leukocytes was detected at a high rate in cases of viral gastroenteritis, especially in rota-adenovirus co-infections. Therefore, clinicians should not consider only bacterial pathogens in the presence of fecal leukocytes.

Changes in the epidemiology and clinical characteristics of viral gastroenteritis among hospitalized children in the Mainland of China: a retrospective study from 2016 to 2020.

BACKGROUND: Acute gastroenteritis (AGE) causes significant morbidity in children worldwide; however, the disease burden of children hospitalized with viral gastroenteritis in China has been rarely described. Through this study, we analyzed the data of hospitalized children with viral gastroenteritis to explore the changes in the epidemiology and clinical characteristics of viral gastroenteritis in the mainland of China. METHODS: Data were extracted from Futang Children's Medical Development Research Center (FRCPD), between 2016 and 2020, across 27 hospitals in 7 regions. The demographics, geographic distribution, pathogenic examination results, complications, hospital admission date, length of hospital stays, hospitalization charges and outcomes were collected and analyzed. RESULTS: Viral etiological agents included rotavirus (RV), adenovirus (ADV), norovirus (NV) and coxsackievirus (CV) that were detected in 25,274 (89.6%), 1,047 (3.7%), 441 (1.5%) and 83 (0.3%) cases. There was a higher prevalence of RV and NV infection among children younger than 3 years of age. RV and NV had the highest detection rates in winter, while ADV in summer. Children with viral gastroenteritis were often accompanied by other diseases, such as myocardial diseases (10.98-31.04%), upper respiratory tract diseases (1.20-20.15%), and seizures (2.41-14.51%). Among those cases, the co-infection rate with other pathogens was 6.28%, with Mycoplasma pneumoniae (M. pneumoniae), Epstein-Barr virus (EBV), and influenza virus (FLU) being the most common pathogens. The median length of stay was 5 days, and the median cost of hospitalization corresponded to587 US dollars. CONCLUSIONS: This finding suggests that viral gastroenteritis, especially those caused by RV, is a prevalent illness among younger children. Co-infections and the presence of other diseases are common. The seasonality and regional variation of viral etiological agents highlight the need for targeted prevention and control measures. Although viral gastroenteritis rarely leads to death, it also results in a significant economic burden on healthcare systems.

Ten different viral agents infecting and co-infecting children with acute gastroenteritis in Southern Italy: Role of known pathogens and emerging viruses during and after COVID-19 pandemic.

Acute gastroenteritis (AGE) represents a world public health relevant problem especially in children. Enteric viruses are the pathogens mainly involved in the episodes of AGE, causing about 70.00% of the cases. Apart from well-known rotavirus (RVA), adenovirus (AdV) and norovirus (NoV), there are various emerging viral pathogens potentially associated with AGE episodes. In this study, the presence of ten different enteric viruses was investigated in 152 fecal samples collected from children hospitalized for gastroenteritis. Real time PCR results showed that 49.3% of them were positive for viral detection with the following prevalence: norovirus GII 19.7%, AdV 15.8%, RVA 10.5%, human parechovirus (HPeV) 5.3%, enterovirus (EV) 3.3%, sapovirus (SaV) 2.6%. Salivirus (SalV), norovirus GI and astrovirus (AstV) 1.3% each, aichivirus (AiV) found in only one patient. In 38.2% of feces only one virus was detected, while co-infections were identified in 11.8% of the cases. Among young patients, 105 were ≤5 years old and 56.0% tested positive for viral detection, while 47 were >5 years old with 40.0% of them infected. Results obtained confirm a complex plethora of viruses potentially implicated in gastroenteritis in children, with some of them previously known for other etiologies but detectable in fecal samples. Subsequent studies should investigate the role of these viruses in causing gastroenteritis and explore the possibility that other symptoms may be ascribed to multiple infections.

Rotavirus trends and distribution of genotypes before and during COVID-19 pandemic era: Bangladesh, 2017-2021.

Rotavirus gastroenteritis is accountable for an estimated 128 500 deaths among children younger than 5 years worldwide, and the majority occur in low-income countries. Although the clinical trials of rotavirus vaccines in Bangladesh revealed a significant reduction of severe rotavirus disease by around 50%, the vaccines are not yet included in the routine immunization program. The present study was designed to provide data on rotavirus diarrhea with clinical profiles and genotypes before (2017-2019) and during the COVID-19 pandemic period (2020-2021). Fecal samples were collected from 2% of the diarrheal patients at icddr,b Dhaka hospital of all ages between January 2017 and December 2021 and were tested for VP6 rotavirus antigen using ELISA. The clinical manifestations such as fever, duration of diarrhea and hospitalization, number of stools, and dehydration and so on were collected from the surveillance database (n = 3127). Of the positive samples, 10% were randomly selected for genotyping using Sanger sequencing method. A total of 12 705 fecal samples were screened for rotavirus A antigen by enzyme immunoassay. Overall, 3369 (27%) were rotavirus antigen-positive, of whom children <2 years had the highest prevalence (88.6%). The risk of rotavirus A infection was 4.2 times higher in winter than in summer. Overall, G3P[8] was the most prominent genotype (45.3%), followed by G1P[8] (32.1%), G9P[8] (6.8%), and G2P[4] (6.1%). The other unusual combinations, such as G1P[4], G1P[6], G2P[6], G3P[4], G3P[6], and G9P[6], were also present. Genetic analysis on Bangladeshi strains revealed that the selection pressure (dN/dS) was estimated as <1. The number of hospital visits showed a 37% drop during the COVID-19 pandemic relative to the years before the pandemic. Conversely, there was a notable increase in the rate of rotavirus positivity during the pandemic (34%, p < 0.00) compared to the period before COVID-19 (23%). Among the various clinical symptoms, only the occurrence of watery stool significantly increased during the pandemic. The G2P[4] strain showed a sudden rise (19%) in 2020, which then declined in 2021. In the same year, G1P[8] was more prevalent than G3P[8] (40% vs. 38%, respectively). The remaining genotypes were negligible and did not exhibit much fluctuation. This study reveals that the rotavirus burden remained high during the COVID-19 prepandemic and pandemic in Bangladesh. Considering the lack of antigenic variations between the circulating and vaccine-targeted strains, integrating the vaccine into the national immunization program could reduce the prevalence of the disease, the number of hospitalizations, and the severity of cases.

Evaluating Acute Viral Gastroenteritis Severity: Modified Vesikari and Clark Scoring Systems.

OBJECTIVE: Acute gastroenteritis (AGE) is the second leading cause of death in children worldwide. Objectively evaluating disease severity is critical for assessing future interventions. We used data from a large, prospective surveillance study to assess risk factors associated with severe presentation using modified Vesikari score (MVS) and Clark score (CS) of severity. METHODS: From December 1, 2012 to June 30, 2016, AGE surveillance was performed for children between 15 days and 17 years old in the emergency, inpatient, and outpatient settings at Vanderbilt's Monroe Carell Jr. Children's Hospital in Nashville, TN. Stool specimens were tested for norovirus, sapovirus, rotavirus, and astrovirus. We compared demographic and clinical characteristics, along with the MVS and CS, by viral detection status and by setting. RESULTS: Of the 6309 eligible children, 4216 (67%) were enrolled, with 3256 (77%) providing a stool specimen. The median age was 1.9 years, 52% were male, and 1387 (43%) of the stool samples were virus positive. Younger age, male sex, hospitalization, and rotavirus detection were significantly associated with higher mean MVS and CS. Non-Hispanic Black race and ethnicity was associated with a lower mean MVS and CS as compared with non-Hispanic white race and ethnicity. Prematurity and enrollment in the ED were associated with higher mean CS. The 2 scoring systems were highly correlated. CONCLUSIONS: Rotavirus continues to be associated with more severe pediatric illness compared with other viral causes of AGE. MVS and CS systems yielded comparable results and can be useful tools to assess AGE severity.

Human adenoviruses in children with gastroenteritis: a systematic review and meta-analysis.

PURPOSE: Human adenoviruses (HAdVs) have always been suggested as one of the main causes of gastroenteritis in children. However, no comprehensive report on the global epidemiology of these viruses in pediatric gastroenteritis is available. METHODS: A systematic search was conducted to obtain published papers from 2003 to 2023 in three main databases PubMed, Scopus, and Web of Science. RESULTS: The estimated global pooled prevalence of HAdV infection in children with gastroenteritis was 10% (95% CI: 9-11%), with a growing trend after 2010. The highest prevalence was observed in Africa (20%, 95% CI: 14-26%). The prevalence was higher in inpatients (11%; 95% CI: 8-13%) and patients aged 5 years old and younger (9%; 95% CI: 7-10%). However, no significant difference was observed between male and female patients (P = 0.63). The most prevalent species was found to be the species F (57%; 95% CI: 41-72%). The most common HAdVs observed in children with gastroenteritis were types 40/41, 38, and 2. Analysis of case-control studies showed an association between HAdV and gastroenteritis in children (OR: 2.28, 95% CI; 1.51-3.44). CONCLUSION: This study provided valuable insights into the importance of HAdVs in children with gastroenteritis, especially in hospitalized and younger children. The results can be used in future preventive measurements and the development of effective vaccines.

Genetic diversity and distribution of noroviruses among all age groups of patients with diarrhea in Amhara National Regional State, Ethiopia.

BACKGROUND: Norovirus (NoV) is the leading cause of diarrheal disease worldwide and the impact is high in developing countries, including Ethiopia. Moreover, there is a significant and fluctuating global genetic diversity that varies across diverse environments over time. Nevertheless, there is a scarcity of data on the genetic diversity of NoV in Ethiopia. OBJECTIVE: This study was aimed to assess the genetic diversity and distribution of NoVs circulating in the Amhara National Regional State, Ethiopia, by considering all age groups. METHODS: A total of 519 fecal samples were collected from diarrheal patients from May 01/2021 to November 30/ 2021. The fecal samples were screened for the presence of NoVs using real-time RT-PCR by targeting a portion of the major capsid protein coding region. The positive samples were further amplified using conventional RT-PCR, and sequenced. RESULTS: The positivity rate of NoV was (8.9%; 46/519). The detection rate of NoV genogroup II (GII) and genogroup I (GI) was 38 (82.6%) and 8 (17.4%), respectively. Overall, five distinct GII (GII.3, GII.6, GII.10, GII.17, and GII.21) and two GI (GI.3 and GI.5) genotypes were detected. Within the GII types, GII.3 was the predominant (34.2%) followed by GII.21 (15.8%), GII.17 (10.5%), GII.6 and GII.10 each (2.6%). Norovirus GII.21 is reported for the first time in Ethiopia. The genetic diversity and distribution of NoVs were significantly different across the four sampling sits and age groups. The phylogenetic analysis revealed close relatedness of the current strains with published strains from Ethiopia and elsewhere. CONCLUSION: The distribution and genetic diversity of NoV was considerably high, with predominance of non-GII.4 genotypes. The GII.21 genotype is a new add on the growing evidences on the genetic diversity of NoVs in Ethiopia. Future nationwide surveillance studies are necessary to gain comprehensive data in Ethiopia.

Emerging Variants of Canine Enteric Coronavirus Associated with Outbreaks of Gastroenteric Disease.

A 2022 canine gastroenteritis outbreak in the United Kingdom was associated with circulation of a new canine enteric coronavirus closely related to a 2020 variant with an additional spike gene recombination. The variants are unrelated to canine enteric coronavirus-like viruses associated with human disease but represent a model for coronavirus population adaptation.

Enteropathogenic viruses associated with acute gastroenteritis among African children under 5 years of age: A systematic review and meta-analysis.

Gastroenteritis viruses are the leading etiologic agents of diarrhea in children worldwide. We present data from thirty-three (33) eligible studies published between 2003 and 2023 from African countries bearing the brunt of the virus-associated diarrheal mortality. Random effects meta-analysis with proportion, subgroups, and meta-regression analyses were employed. Overall, rotavirus with estimated pooled prevalence of 31.0 % (95 % CI 24.0-39.0) predominated in all primary care visits and hospitalizations, followed by norovirus, adenovirus, sapovirus, astrovirus, and aichivirus with pooled prevalence estimated at 15.0 % (95 % CI 12.0-20.0), 10 % (95 % CI 6-15), 4.0 % (95 % CI 2.0-6.0), 4 % (95 % CI 3-6), and 2.3 % (95 % CI 1-3), respectively. Predominant rotavirus genotype was G1P[8] (39 %), followed by G3P[8] (11.7 %), G9P[8] (8.7 %), and G2P[4] (7.1 %); although, unusual genotypes were also observed, including G3P[6] (2.7 %), G8P[6] (1.7 %), G1P[6] (1.5 %), G10P[8] (0.9 %), G8P[4] (0.5 %), and G4P[8] (0.4 %). The genogroup II norovirus predominated over the genogroup I-associated infections (84.6 %, 613/725 vs 14.9 %, 108/725), with the GII.4 (79.3 %) being the most prevalent circulating genotype. In conclusion, this review showed that rotavirus remains the leading driver of viral diarrhea requiring health care visits and hospitalization among under-five years children in Africa. Thus, improved rotavirus vaccination in the region and surveillance to determine the residual burden of rotavirus and the evolving trend of other enteric viruses are needed for effective control and management of cases.

Autochthonous and imported giardiasis cases: An analysis of two decades of national surveillance data, Germany, 2002 to 2021.

BackgroundGiardia duodenalis is a major cause of gastroenteritis globally, and is the most common food- and waterborne parasitic infection in Europe.AimTo describe the epidemiology of reported acute giardiasis cases in Germany and compare demographic and clinical characteristics between imported and autochthonous cases.MethodsWe conducted a descriptive analysis of giardiasis cases that fulfilled the national case definition and were reported between January 2002 and December 2021. We defined an imported case as having at least one place of exposure abroad in the 3-25 days before symptom onset. We analysed case numbers and incidence by age, sex, month reported and geographic region, both overall and stratified by autochthonous and imported cases.ResultsFrom 2002 to 2021, 72,318 giardiasis cases were reported in Germany, corresponding to a mean annual incidence of 4.4 per 100,000 population. Annual incidence gradually decreased since 2013, declining sharply during the COVID-19 pandemic in 2020-21. Of 69,345 cases reported between 2002 and 2019, 35% were imported. Incidence of autochthonous cases (overall yearly mean: 3.1/100,000) was highest in males and young children (< 5 years); imported cases were predominantly adults aged 20-39 years. We identified seasonal patterns for imported and autochthonous cases.ConclusionsGiardiasis in Germany is typically assumed to be imported. Our data, however, underline the importance of autochthonous giardiasis. Travel advice might reduce imported infections, but prevention strategies for autochthonous infections are less clear. Dietary, behavioural and environmental risk factors need to be further investigated to enhance infection prevention measures for autochthonous giardiasis.

Rotavirus vaccines in Africa and Norovirus genetic diversity in children aged 0 to 5 years old: a systematic review and meta-analysis : Rotavirus vaccines in Africa and Norovirus genetic diversity.

Noroviruses are the second leading cause of death in children under the age of 5 years old. They are responsible for 200 million cases of diarrhoea and 50,000 deaths in children through the word, mainly in low-income countries. The objective of this review was to assess how the prevalence and genetic diversity of noroviruses have been affected by the introduction of rotavirus vaccines in Africa. PubMed, Web of Science and Science Direct databases were searched for articles. All included studies were conducted in Africa in children aged 0 to 5 years old with gastroenteritis. STATA version 16.0 software was used to perform the meta-analysis. The method of Dersimonian and Laird, based on the random effects model, was used for the statistical analyses in order to estimate the pooled prevalence's at a 95% confidence interval (CI). Heterogeneity was assessed by Cochran's Q test using the I2 index. The funnel plot was used to assess study publication bias. A total of 521 studies were retrieved from the databases, and 19 were included in the meta-analysis. The pooled norovirus prevalence's for pre- and post-vaccination rotavirus studies were 15% (95 CI, 15-18) and 13% (95 CI, 09-17) respectively. GII was the predominant genogroup, with prevalence of 87.64% and 91.20% respectively for the pre- and post-vaccination studies. GII.4 was the most frequently detected genotype, with rates of 66.84% and 51.24% respectively for the pre- and post-vaccination studies. This meta-analysis indicates that rotavirus vaccination has not resulted in a decrease in norovirus infections in Africa.

Human transmission and outbreaks of feline-like G6 rotavirus revealed with whole-genome analysis of G6P[9] feline rotavirus.

Group A rotaviruses (RVAs) are generally highly species-specific; however, some strains infect across species. Feline RVAs sporadically infect humans, causing gastroenteritis. In 2012 and 2013, rectal swab samples were collected from 61 asymptomatic shelter cats at a public health center in Mie Prefecture, Japan, to investigate the presence of RVA and any association with human infections. The analysis identified G6P[9] strains in three cats and G3P[9] strains in two cats, although no feline RVA sequence data were available for the former. A whole-genome analysis of these G6P[9] strains identified the genotype constellation G6-P[9]-I2-R2-C2-M2-A3-N2-T3-E3-H3. The nucleotide identity among these G6P[9] strains exceeded 99.5% across all 11 gene segments, indicating the circulation of this G6P[9] strain among cats. Notably, strain RVA/Human-wt/JPN/KF17/2010/G6P[9], previously detected in a 3-year-old child with gastroenteritis, shares high nucleotide identity (>98%) with Mie20120017f, the representative G6P[9] strain in this study, across all 11 gene segments, confirming feline RVA infection and symptomatic presentation in this child. The VP7 gene of strain Mie20120017f also shares high nucleotide identity with other sporadically reported G6 RVA strains in humans. This suggests that feline-origin G6 strains as the probable source of these sporadic G6 RVA strains causing gastroenteritis in humans globally. Moreover, a feline-like human G6P[8] strain circulating in Brazil in 2022 was identified, emphasizing the importance of ongoing surveillance to monitor potential global human outbreaks of RVA.

Epidemiological Surveillance: Genetic Diversity of Rotavirus Group A in the Pearl River Delta, Guangdong, China in 2019.

Objective: This study aimed to understand the epidemic status and phylogenetic relationships of rotavirus group A (RVA) in the Pearl River Delta region of Guangdong Province, China. Methods: This study included individuals aged 28 days-85 years. A total of 706 stool samples from patients with acute gastroenteritis collected between January 2019 and January 2020 were analyzed for 17 causative pathogens, including RVA, using a Gastrointestinal Pathogen Panel, followed by genotyping, virus isolation, and complete sequencing to assess the genetic diversity of RVA. Results: The overall RVA infection rate was 14.59% (103/706), with an irregular epidemiological pattern. The proportion of co-infection with RVA and other pathogens was 39.81% (41/103). Acute gastroenteritis is highly prevalent in young children aged 0-1 year, and RVA is the key pathogen circulating in patients 6-10 months of age with diarrhea. G9P[8] (58.25%, 60/103) was found to be the predominant genotype in the RVA strains, and the 41 RVA-positive strains that were successfully sequenced belonged to three different RVA genotypes in the phylogenetic analysis. Recombination analysis showed that gene reassortment events, selection pressure, codon usage bias, gene polymorphism, and post-translational modifications (PTMs) occurred in the G9P[8] and G3P[8] strains. Conclusion: This study provides molecular evidence of RVA prevalence in the Pearl River Delta region of China, further enriching the existing information on its genetics and evolutionary characteristics and suggesting the emergence of genetic diversity. Strengthening the surveillance of genotypic changes and gene reassortment in RVA strains is essential for further research and a better understanding of strain variations for further vaccine development.

Epidemiological and molecular surveillance of norovirus in the Brazilian Amazon: description of recombinant genotypes and improvement of evolutionary analysis.

Noroviruses are highly infectious, genetically diverse viruses. Global outbreaks occur frequently, making molecular surveillance important for infection monitoring. This cross-sectional descriptive study aimed to monitor cases of norovirus gastroenteritis in the Brazilian Amazon. Fecal samples were tested by immunoenzymatic assay, RT-PCR and genetic sequencing for the ORF1/ORF2 and protease regions. Bayesian inference with a molecular clock was employed to construct the phylogeny. The norovirus prevalence was 25.8%, with a higher positivity rate among children aged 0-24 months. Genogroup GII accounted for 98.1% of the sequenced samples, while GI accounted for 1.9% of them. The GII.P16/GII.4 genotype was the most prevalent, with an evolution rate of 2.87x10-3 and TMRCA estimated in 2012. This study demonstrates that norovirus is a primary causative agent of gastroenteritis and provides data on viral genetic diversity that may facilitate infection surveillance and vaccine development.

Economic Burden of Acute Gastroenteritis among Members of Integrated Healthcare Delivery System, United States, 2014-2016.

We conducted a large surveillance study among members of an integrated healthcare delivery system in Pacific Northwest of the United States to estimate medical costs attributable to medically attended acute gastroenteritis (MAAGE) on the day care was sought and during 30-day follow-up. We used multivariable regression to compare costs of MAAGE and non-MAAGE cases matched on age, gender, and index time. Differences accounted for confounders, including race, ethnicity, and history of chronic underlying conditions. Analyses included 73,140 MAAGE episodes from adults and 18,617 from children who were Kaiser Permanente Northwest members during 2014-2016. Total costs were higher for MAAGE cases relative to non-MAAGE comparators as were costs on the day care was sought and costs during follow-up. Costs of MAAGE are substantial relative to the cost of usual-care medical services, and much of the burden accrues during short-term follow-up.

Antigenic Characterization of Novel Human Norovirus GII.4 Variants San Francisco 2017 and Hong Kong 2019.

Norovirus is a major cause of acute gastroenteritis; GII.4 is the predominant strain in humans. Recently, 2 new GII.4 variants, Hong Kong 2019 and San Francisco 2017, were reported. Characterization using GII.4 monoclonal antibodies and serum demonstrated different antigenic profiles for the new variants compared with historical variants.

Trends in the detection of viruses causing gastroenteritis over a 10-year period and impact of nonpharmaceutical interventions.

BACKGROUND: Viral gastroenteritis continues to be a leading cause of death in low-income countries. The impact of nonpharmaceutical interventions (NPIs) on the transmission of gastroenteritis-causing viruses during the COVID-19 pandemic is understudied. OBJECTIVES: To investigate the 10-year trends of enteric viruses and estimate the impact of implementing and mitigating NPIs. STUDY DESIGN: Data regarding norovirus, rotavirus, adenovirus, astrovirus, and sapovirus detection were collected from five Korean hospitals between January 2013 and April 2023. We compared positivity between the pre-pandemic, pandemic, and post-pandemic periods. The causal effects of implementing and mitigating NPIs were quantified using the Bayesian Structural Time Series (BSTS) model. RESULTS: Norovirus was most frequently detected (9.9 %), followed by rotavirus (6.7 %), adenovirus (3.3 %), astrovirus (1.4 %), and sapovirus (0.6 %). During the pandemic, the positivity of all five viruses decreased, ranging from -1.0 % to -8.1 %, with rotavirus showing the greatest decrease. In the post-pandemic period, positivity rebounded for all viruses except for rotavirus. The BSTS model revealed that NPI implementation negatively affected the detection of all five viruses, resulting in reductions ranging from -73.0 % to -91.0 % compared to the prediction, with rotavirus being the least affected. Conversely, NPI mitigation positively affected the detection of all viruses, ranging from 79.0 % to 200.0 %, except for rotavirus. CONCLUSIONS: Trends observed over 10 years show that NPIs have had a major impact on changes in enteric virus detection. The effect of vaccines, in addition to NPIs, on rotavirus detection requires further investigation. Our findings emphasize the importance of NPIs in infection control and prevention.

Epidemiological and genetic characteristics of norovirus in Hangzhou, China, in the postepidemic era.

OBJECTIVE: Norovirus (NoV) is an important human pathogen that can cause severe gastroenteritis in vulnerable populations. This study aimed to analyze the epidemiological and genetic characteristics of 2021-2023 NoV in Hangzhou, China. METHODS: This study enrolled patients aged 0-18 years who underwent NoV RNA detection in the hospital between January 2021 and October 2023 and analyzed the epidemiological characteristics of NoV. Polymerase chain reaction (PCR) was used to detect NoV RNA. Subtype classification and whole-genome sequencing were performed. RESULTS: There was a high prevalence of NoV infection in 2023, with NoV-positive samples accounting for 63.10 % of the total number of positive samples collected during the three-year period. The prevalence was abnormally high in summer, and the number of positive samples accounted for 48.20 % of the total positive samples for the whole year, which was much greater than the level in the same period in previous years (2023, 48.20% vs 2021, 13.66% vs 2022, 15.21 %). The GⅡ.4 subtype played a leading role, followed by increased mixed infection with GⅠ.5 and GⅡ.4. Whole-genome sequencing results suggested that GII.P16-GⅡ.4 had R297H and D372N key locus mutations. The evolutionary rate was 4.29 × 10-3 for the RdRp gene and 4.84 × 10-3 for the VP1 gene. The RdRp gene and VP1 gene of NoV GII.P16-GⅡ.4 have undergone rapid population evolution during the COVID-19 epidemic. CONCLUSION: In the summer of 2023, an abnormally high incidence of NoV appeared in Hangzhou, China. The major epidemic strain GII.P16-GⅡ.4 showed a certain range of gene mutations and a fast evolutionary rate.