title: Molecular epidemiology and genotype distribution of noroviruses in children in Thailand from 2004 to 2010: a multi-site study.
abstract: This study identified norovirus in children presenting with acute gastroenteritis and determined the capsid genotypes of the circulating norovirus strains in multiple regions in Thailand during October 2004 to December 2006 and March 2008 to August 2010. A total of 7,420 stool samples were collected from both cases (3621) and controls (3799). The stool samples were screened by two real-time RT-PCR assays to detect genogroup I and genogroup II noroviruses. Norovirus-positive samples were identified in 516 cases (14.3%) and 181 controls (4.8%) with more than half of norovirus positive samples from 7-24 months old children. Positive samples were sequenced and genotyped for the capsid gene. GII.4 was the genotype observed most frequently (56.4%) followed by GII.3 (28.2%). Five peaks of infection were observed, with predominant capsid genotypes that alternated during the surveillance periods between GII.4 and GII.3. Analyses of positive samples showed variation in genotype from each region as well as from different study periods. This emphasizes the importance of multi-site studies to investigate norovirus epidemiology. Additionally, the observed regional and temporal variations suggest that a systematic nation-wide surveillance effort in Thailand is needed to track the continually changing norovirus epidemiology.
authors: Department of Enteric Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.
authors: Ladaporn
authors: L
authors: Bodhidatta
authors: Eugenio
authors: E
authors: Abente
authors: Pimmnapar
authors: P
authors: Neesanant
authors: Kaewkanya
authors: K
authors: Nakjarung
authors: Pantip
authors: P
authors: Sirichote
authors: Gaysorn
authors: G
authors: Bunyarakyothin
authors: Niyada
authors: N
authors: Vithayasai
authors: Carl J
authors: CJ
authors: Mason
mesh_terms: D017250:Caliciviridae Infections / Q000453:epidemiology* / Q000821:virology*; D036022:Capsid Proteins / Q000235:genetics; D002675:Child, Preschool; D016000:Cluster Analysis; D005243:Feces / Q000821:virology; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D008297:Male; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D029322:Norovirus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D010802:Phylogeny; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013785:Thailand / Q000453:epidemiology
chemical_list: D036022:Capsid Proteins
keywords: diarrhea; pediatric; surveillance