title: Monitoring of Calicivirus among day-care children: evidence of asymptomatic viral excretion and first report of GI.7 Norovirus and GI.3 Sapovirus in Brazil.
abstract: Caliciviruses (Norovirus and Sapovirus) are important causes of acute gastroenteritis, with Norovirus (NoV) considered the leading cause of epidemic non-bacterial acute gastroenteritis; however, molecular and epidemiological data of the circulating Calicivirus (CV) strains among day-care children are still considered scarce. The role of asymptomatic CV excretion on viral transmission also remains poorly understood. The aim of the present study was to monitor the occurrence of NoV and Sapovirus (SaV) in a day-care center and to describe the molecular epidemiology of the circulating strains. Genomic sequencing and phylogenetic analysis of the capsid region were carried out in CV positive samples obtained from children younger than 5 years, with or without diarrhea, between October 2009 and October 2011. A total of 539 fecal samples were screened for CV. Forty-three (8%) were positive for NoV and 25 (4.6%) for SaV. Surprisingly, positivity rates for CV were significant in asymptomatic children, and virus circulation was detected in every month of the study. Great genomic diversity of CV was observed, and the circulating NoV strains were: GII.6, GII.2, GII.1, GI.7, GII.4, and GI.1. The SaV genotypes GI.1 and GI.3 were also detected. Five CV outbreaks caused by distinct viral strains were documented. This study provides an insight on the genetic diversity of CV in a day-care in Central West Brazil, highlighting the probable role of asymptomatic viral excretion and the significance of semi-closed settings in the dissemination of these agents.
authors.affiliation: Laboratory of Virology, Institute of Tropical Pathology and Public Health, Federal University of Goiás, Goiânia, Goiás, Brazil.
authors.forename: Denisy
authors.initials: D
authors.lastname: Marques Mendanha de Oliveira
authors.forename: Menira
authors.initials: M
authors.lastname: Souza
authors.forename: Fabíola
authors.initials: F
authors.lastname: Souza Fiaccadori
authors.forename: Hugo
authors.initials: H
authors.lastname: César Pereira Santos
authors.forename: Divina
authors.initials: D
authors.lastname: das Dôres de Paula Cardoso
mesh_terms: D058345:Asymptomatic Infections / Q000453:epidemiology; D001938:Brazil / Q000453:epidemiology; D017250:Caliciviridae Infections / Q000453:epidemiology* / Q000821:virology; D036022:Capsid Proteins / Q000235:genetics; D002656:Child Day Care Centers; D002675:Child, Preschool; D004196:Disease Outbreaks; D062665:Epidemiological Monitoring; D005243:Feces / Q000821:virology; D005260:Female; D005759:Gastroenteritis / Q000453:epidemiology* / Q000821:virology; D005814:Genes, Viral; D006801:Humans; D007223:Infant; D008297:Male; D017720:Molecular Epidemiology; D029322:Norovirus / Q000235:genetics* / Q000302:isolation & purification; D010802:Phylogeny; D029341:Sapovirus / Q000235:genetics* / Q000302:isolation & purification; D017422:Sequence Analysis, DNA
chemical_list: D036022:Capsid Proteins
keywords: asymptomatic children; day-care center; molecular epidemiology; norovirus; sapovirus