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Your search keyword '"G. Riviello-López"' showing total 2 results
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2 results on '"G. Riviello-López"'

1. Analysis of the circulation of hepatitis A virus in Argentina since vaccine introduction

Author

M.D. Blanco Fernández, Daniel Cisterna, Hugo Ramiro Poma, Viviana Andrea Mbayed, G. Riviello-López, Roberto Campos, Silvia Nates, Verónica Beatriz Rajal, and Carolina Torres

Subjects
Adult, Male, Microbiology (medical), Adolescent, Genotype, Vaccination schedule, viruses, Population, Molecular Sequence Data, environmental surveillance, Argentina, Disease, Biology, immunization, Antigenic drift, Young Adult, Rivers, genotypes, hepatitis A virus, Humans, education, Child, education.field_of_study, Hepatitis A Vaccines, Incidence (epidemiology), Infant, General Medicine, Sequence Analysis, DNA, Hepatitis A, Virology, Hepatitis a virus, Infectious Diseases, Immunization, Child, Preschool, Immunology, RNA, Viral, Female
Abstract

Hepatitis A virus (HAV) has shown intermediate endemicity in Argentina, but its incidence has decreased since vaccine introduction in 2005. Environmental surveillance was conducted in five rivers from Argentina from 2005 to 2012, complementing clinical information. HAV detection decreased since 2005, although its circulation continues, maintaining viral diversity but not undergoing antigenic drift. Most sequences belonged to subgenotype IA, closely related to Argentinean clinical sequences, but one belonged to proposed subgenotype IC, previously undetected in the country. Environmental surveillance might contribute to monitoring the single-dose vaccination schedule, representing not only strains causing disease but also the circulating population and the viral introductions.

Published
2012
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2. Environmental surveillance of norovirus in Argentina revealed distinct viral diversity patterns, seasonality and spatio-temporal diffusion processes.

Author

Fernández MD, Torres C, Poma HR, Riviello-López G, Martínez LC, Cisterna DM, Rajal VB, Nates SV, and Mbayed VA

Subjects
Argentina epidemiology, Base Sequence, Biodiversity, Caliciviridae Infections transmission, Cities, Genetic Variation, Genotype, Humans, Models, Biological, Molecular Sequence Data, Norovirus classification, Norovirus genetics, Phylogeny, Phylogeography, Seasons, Sequence Analysis, DNA, Sewage virology, Caliciviridae Infections epidemiology, Environmental Monitoring, Norovirus isolation & purification, Rivers virology
Abstract

Norovirus (NoV) contamination was evaluated in five rivers of Argentina between 2005 and 2011. NoV was present in all sampled rivers, with distinct NoV patterns in waters impacted by different-sized communities. In rivers affected by medium-sized populations (Salta and Córdoba cities) only one or two genotypes were present, GII.4 being the main one, with winter seasonality. In contrast, in the much more heavily populated area of Buenos Aires city the prevalent GII.4 was accompanied by several additional genotypes (GII.4, GII.b, GII.2, GII.7, GII.17, GII.e and GII.g) and one ungenotyped GII NoV, with no clear seasonality. GII.4 2006b was the main variant detected (60.9%). Phylogeographic and phylodynamic analyses performed in region D of the VP1 gene showed a most recent common ancestor in 2002 and a substitution rate of 3.7×10(-3) substitutions per site per year (HPD95%=2.3×10(-3)-5.2×10(-3)) for this variant still involving a significant population size with a slight decrease since 2008. The spatio-temporal diffusion analysis proposed Europe as an intermediate path between the American Continent and the rest of the World for NoV dissemination. Given the importance of NoV as a cause of epidemic gastroenteritis and the likelihood of its environmental transmission, the results of this work should increase public and institutional awareness of the health risk involved in sewage discharges into the environment. Environmental surveillance of enteric viruses could be a very useful tool not only to prevent waterborne outbreaks, but also to describe the epidemiology of the viruses. The detailed analysis of the viral genomes disposed into the environment contributed to the characterization of the dissemination, diversity and seasonality of NoV in its natural host population. In future studies, environmental surveillance and molecular analysis should be complemented with a quantitative viral risk assessment for estimating the disease burden from viruses in the environment., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Published
2012
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