The ABI Prism 7500 sequence detection system (Applied Biosystems, Foster City, CA, USA) was used for the amplification and detection of the MS2 and Enterovirus RNA by TaqMan technology as previously described [5, 29, 30] . Briefly, for MS2 rRT-PCR, 5 ml of RNA was added to the AgPath Mastermix (Ambion, Applied Biosystems Inc, Foster City, California), which contained the published concentrations of primers and probes and 5-carboxy-X-rhodamine succinimidyl ester (ROX) as an internal reference dye, whereas 8 ml of RNA was added for all enterovirus rRT-PCR assays. rRT-PCR was performed under the following conditions: 30 min at 48uC, 10 min at 95uC, and 60 cycles of 15 s at 95uC and 1 min at 60uC. RNAs extracted from the same stool suspension by the four procedures were assayed on the same rRT-PCR run to minimize analytical differences [19] .