To develop a real-time diagnostic technique with e- Ab sensor for Entervirus 71 detection, the investigators conduct a prospective clinical study. In comparison with results from direct sequencing of Entervirus 71, the investigators evaluate the performance of e- Ab sensor, including reproducibility, sensitivity, specificity, and cross-reaction. The potential factors which may interfere with the results would be investigated. With such technique, the investigators hope to make early diagnosis and give EV71 patients early treatment to reduce the complications and case-fatality rate.