Molecular Epidemiology and Genetic Diversity of Norovirus in Young Children in Phnom Penh,Cambodia

This study investigated the genetic diversity of noroviruses identified from a previous surveillance study conducted at the national pediatric hospital in phnom penh,cambodia,from 2004 to 2006. in the previous study,926 stool samples were collected from children aged 3-60 months with acute diarrhea (cases) and without diarrhea (controls) with reported 6.7% of cases and 3.2% of controls being positive for norovirus. the initial norovirus diagnostic assay was performed with real-time reverse transcription-polymerase chain reaction (real-time rt pcr) which also distinguished between genogroups i and ii (gi and gii). norovirus infection was most commonly detected in children aged 12-23 months in both cases and controls. norovirus genotyping tool and phylogenetic analysis of partial sequences of the 3′ end of the rna-dependent rna polymerase (rdrp) and the capsid domain region were employed to assign genotypes of the norovirus strains. gii.4 was the most predominant capsid genotype detected at 39.5% followed by gii.6 at 14.9%. the gii.4 hunter 2004 variant was the predominant strain detected. six rdrp/capsid recombinants including gii.p7/gii.6,gii.p7/gii.14,gii.p7/gii.20,gii.p12/gii.13,gii.p17/gii.16,and gii.p21/gii.3 were also identified. this study of norovirus infection in young children in cambodia suggests genetic diversity of norovirus as reported worldwide. � 2016 kaewkanya nakjarung et al.