Norovirus outbreaks in a nursery school in Buenos Aires, Argentina.

Norovirus (NoV) is the leading cause of outbreaks of acute gastroenteritis worldwide. These are non-enveloped viruses that are classified into 10 genogroups, of which genogroup I (GI), II (GII), IV (GIV), VIII (GVIII), and IX (GIX) are the ones that infect humans. Two outbreaks (A and B) of acute gastroenteritis that occurred in a nursery school are described.

Enteric viruses other than rotavirus and norovirus in children under 5 years of age with gastroenteritis in Argentina, 2010-2021. A descriptive study.

Introduction. Data on the frequency of enteric adenoviruses, sapoviruses, and astroviruses in cases of sporadic acute gastroenteritis in Argentina are scarce. Methods.

Genetic diversity of rotavirus A in Argentina during 2019-2022: detection of G6 strains and insights regarding its dissemination.

One of the challenges associated with introducing a vaccine is monitoring its impact through clinical and molecular surveillance. The aims of this study were to analyze the genetic diversity of rotavirus A in Argentina between 2019 and 2022 and to assess the phylogenetic and phylodynamic features of the unusual G6 strains detected. A significant decline in the Wa-like genogroup strains was observed, and G6 strains were detected for the first time in Argentina, in association with P[8] and P[9].

Role of Noroviruses in Sporadic Acute Gastroenteritis Cases from Children Attending a Large Referral Children's Hospital in Buenos Aires City, Argentina.

Background: Noroviruses (NVs) are recognized as the leading cause of sporadic and epidemic acute gastroenteritis worldwide, in all age groups. Although there is increasing knowledge that NVs are responsible for many acute gastroenteritis outbreaks in Argentina, studies to estimate prevalence in sporadic cases are scarce.

Methods: A descriptive, observational and cross-sectional study was conducted with children under 5 years with acute gastroenteritis attending the outpatient department at the "Ricardo Gutiérrez" Children's Hospital (RGCH) in Buenos Aires City between June 2017 and June 2021.

Phylogeography of Rotavirus G8P[8] Detected in Argentina: Evidence of Transpacific Dissemination.

Rotavirus is one of the leading causes of diarrhea in children. In 2018, G8P[8], an unusual association of genotypes, was detected with moderate frequency in symptomatic children in Argen-tina, unlike a previous sporadic identification in 2016. The aim of this study was to analyze the dissemination pattern of the G8P[8]-lineage IV strains detected in Argentina.

Genome-wide analyses of human noroviruses provide insights on evolutionary dynamics and evidence of coexisting viral populations evolving under recombination constraints.

Norovirus is a major cause of acute gastroenteritis worldwide. Over 30 different genotypes, mostly from genogroup I (GI) and II (GII), have been shown to infect humans. Despite three decades of genome sequencing, our understanding of the role of genomic diversification across continents and time is incomplete.

Norovirus passive surveillance as an alternative strategy for genetic diversity assessment in developing countries.

In developing countries, the acute gastroenteritis outbreaks submitted for viral testing are limited due to deficient surveillance programs. The aim of this study was to analyze a passive surveillance strategy for monitoring the molecular epidemiology of norovirus (NV) and counterbalance the genetic diversity data gap. Laboratory-confirmed rotavirus negative sporadic stool samples (N = 523) collected between 2010 and 2017 from children were selected from our archival collection and were tested for NV and sequencing was performed on the positive samples.

Emergence of unusual rotavirus G9P[4] and G8P[8] strains during post vaccination surveillance in Argentina, 2017-2018.

Introduction: In 2015, Argentina included Rotarix™ monovalent vaccine for universal administration and it showed a sharp decline in all-cause and rotavirus-confirmed cases as well as an immediate predominance of the G2P[4] genotype. The aim of this study was to analyze the impact of rotavirus vaccination on laboratory-confirmed cases and genotype distribution in Argentina following its introduction.

Material And Methods: Prevalence and seasonality of laboratory-confirmed rotavirus cases data were assessed.

Persistent infection with a rotavirus vaccine strain in a child suffering from Severe Combined Immunodeficiency in Argentina.

Due to the high burden of disease associated with rotavirus, the massive vaccination in children before six months of age has been encouraged. Currently licensed oral live vaccines have shown low risk of associated adverse events in the general population. Noteworthy, postmarketing reports of severe gastroenteritis with persistent vaccine viral shedding in children with severe combined immunodeficiency (SCID) have led companies to include this inborn error of immunity as an additional contraindication.

Molecular epidemiology of norovirus outbreaks in Argentina, 2013-2018.

Noroviruses are a leading cause of endemic and epidemic acute gastroenteritis in all age groups. However, in Latin America, there are limited and updated data regarding circulating genotypes. The aim of this study was to assess the prevalence and genetic diversity of norovirus outbreaks in Argentina from 2013 to 2018.

Recombinant Nontypeable Genotype II Human Noroviruses in the Americas.

We report multiple nontypeable genotype II noroviruses circulating in South America; nucleotides differed by >25% from those of other genotypes. These viruses have been circulating in the Americas for ≈20 years and show recombination with other genotypes. Clues to norovirus natural history can guide development of treatment and prevention plans.

Genotype distribution of Group A rotavirus in children before and after massive vaccination in Latin America and the Caribbean: Systematic review.

Background: During the last decade, most of Latin American and the Caribbean (LAC) countries have implemented oral live rotavirus vaccines in their national vaccination programs with remarkable results. However, it has been suggested that massive vaccination could lead to the replacement of circulating genotypes or the emergence of new variants or neutralizing antibodies escape mutants, which may reduce the effectiveness of the vaccine. The objective was to analyze the genetic diversity of Group A rotavirus before and after the introduction of universal vaccination in LAC.

Detection of novel GII.17 norovirus in Argentina, 2015.

During the winter of 2014-2015 a novel GII.17 norovirus strain emerged as a cause of large gastroenteritis outbreaks in Asia; displacing the long-term predominant strain, GII.4.

Rotavirus epidemiology and surveillance before vaccine introduction in Argentina, 2012-2014.

Group A Rotavirus has been widely described as one of the most important infantile diarrheal pathogens worldwide. In Argentina, it is responsible for over 200,000 acute diarrhea cases and from 30 to 50 deaths annually in children under 5 years. The aim of this study is to analyze frequency, seasonality, age group distribution, and circulating genotypes based on data notified in the 2012-2014 period and in turn to assess the pre-vaccine scenario, considering that rotavirus vaccine was introduced in 2015.

Genetic diversity of G3 rotavirus strains circulating in Argentina during 1998-2012 assessed by full genome analyses.

Seasonal shifts in the predominant strains and the periodic emergence of new strains are epidemiological features of human rotaviruses. After the sporadic detection in two samples in 1998, G3P[8] strains reemerged as the predominant rotavirus during 2008-2009 in Argentina. Notably, in 2011 6.

[Rotavirus epidemiology and surveillance in Argentina: 2009-2011].

It has been estimated that in Argentina, rotavirus causes approximately 80,000 to 100,000 clinic consultations annually and is responsible for 40% of acute diarrhea related hospital admissions in children under 5 years. In this study, national rotavirus surveillance data from 2009-2011 was consulted to asses prevalence, seasonality, age-group distribution as well as the national and regional genotypes circulating. It is essential to get deeper insight into the epidemiology and burden of rotavirus diarrhea for design of strategies and health interventions in order to prevent and control high impact human diseases.

Increased frequency of rotavirus G3P[8] and G12P[8] in Argentina during 2008-2009: whole-genome characterization of emerging G12P[8] strains.

Background: Group A rotaviruses are the leading cause of non-bacterial severe diarrhea disease in infants and young children. In humans, the most common genotypes are G1-G4 and G9. Recently, G12 strains have been sporadically reported in several countries, including Argentina, Brazil and Paraguay.

Burden and typing of rotavirus group A in Latin America and the Caribbean: systematic review and meta-analysis.

The efficacy of licensed rotavirus vaccines has only been shown against certain rotavirus group A (RV-A) types. It is critical to understand the burden of rotavirus gastroenteritis (RVGE) and its prevalent types to assess the potential impact of these vaccines in Latin America and the Caribbean (LA&C). We performed a systematic review and meta-analyses of all the available evidence reported from 1990 to 2009 on the burden of rotavirus disease and strains circulating in LA&C.

National Rotavirus Surveillance in Argentina: high incidence of G9P[8] strains and detection of G4P[6] strains with porcine characteristics.

Group A rotaviruses are the most frequently detected viral agents associated with diarrhea in infants and children worldwide. It has been estimated that every year almost 120,000 cases of diarrhea associated with rotavirus occur in children under 5 years old in Argentina. In this work, we present the rotavirus strain diversity detected during the first 2 years of the National Surveillance Network for Diarrheas implemented by the Ministry of Health in Argentina.

Molecular characterization of calicivirus strains detected in outbreaks of gastroenteritis in Argentina.

Eight outbreaks of acute gastroenteritis occurred in Argentina in 2004 were tested for the presence of Calicivirus, Rotavirus and Astrovirus as possible causative agents. Caliciviruses were found in 39 out of the 100 tested samples, followed by six Astrovirus-positive samples and two Rotavirus-positive samples. Thirty-seven out of the 39 Calicivirus-positive samples were typed as Norovirus while the remaining two were typed as Sapovirus.

Detection of human rotavirus G9P[8] strains circulating in Argentina: phylogenetic analysis of VP7 and NSP4 genes.

During the surveillance of rotavirus strains that were circulating in Argentinean children from 2000 to 2004, seven rotaviruses were detected bearing the genotype combination G9P[8]. The molecular characterization of the VP7 and NSP4 genes and the RNA migration patterns support the hypothesis that rotaviruses G9 could have been reintroduced into Argentina as a novel G9P[8] strain, rather than represent VP7 gene reassortants from G9P[6] strains that had been circulating previously in this country.