Four different RT-PCR assays directed toward various regions of ORF1b were used for astrovirus detection and differentiation. Conventional RT-PCR was performed using a QIAGEN OneStep RT-PCR kit (QIAGEN, Germany), and the products were separated on a 2% agarose gel in Tris-acetate-EDTA buffer and visualized using ethidium bromide stain. Real-time RT-PCR was performed using a QuantiTect Probe RT-PCR Kit (QIAGEN, Germany) in a 7500 Real Time PCR System (Applied Biosystems, USA).