Genotyping targeting the capsid genes was conducted by previously described PCR and sequencing methods [7 (link)8 (link)]. Briefly, rotavirus G (VP7) and P (VP4) genotyping was performed according to the WHO manual, using specific primer sets [9 ], with some modifications. Norovirus capsid genotyping was performed using specific primer sets [8 (link)], and adenovirus capsid hexon genotyping was performed by PCR and sequencing using a specified primer set (ADHEX1F/AD2) or a different primer set (AD1/AD2) [10 (link)]. Additionally, astrovirus and sapovirus genotyping was performed by PCR and sequencing techniques using specific capsid primer sets [11 (link)12 (link)]. The PCR products were visualized by electrophoresis on an agarose gel and analyzed by DNA sequencing. The nucleotide sequences were analyzed using ABI Prism BigDye Terminator version 3.1 (Applied Biosystems, Foster City, CA, USA), and the genotypes were confirmed using the NCBI BLAST server of the GenBank database.