目標：本文陳述5歲以下幼兒急性腸胃炎的感染原及輪狀病毒感染的臨床現象。方法：本研究利用2001年4月到2002年10月之間，四家醫學中心向衛生署疾病管制局通報的幼兒急性腸胃炎資料，區分住院、急診和門診病人，觀察輪狀病毒感染之性別、年齡及臨床症狀分布。結果：在通報的2477位急性腸胃炎病童中，以住院病人最多(74.8%)，急診病人其次(22.3%)，門診病患很少(2.9%)。不同來源病患的年齡分布主要集中在6∼36個月大的小孩(65.2%)，高峰出現在6∼11個月大(20.6%)。實驗室檢驗結果顯示輪狀病毒為幼兒急性腸胃炎主要病原(43.6%)，檢體中輪狀病毒的陽性率以住院病人最高47.1%，其次為急診病患和門診病人，分別為33.9%和28.8%。細菌及腺病毒的陽性率相對較低，合計分別為10.0%和2.4%，亦以住院病人為高。檢體中檢驗出2種以上病原的分率也以住院病人較高(4.5%)。輪狀病毒感染住院病童出現發燒、嘔吐及脫水症狀的機會明顯較其他病童高。結論：由醫學中心通報的幼兒急性腸胃炎超過四成和輪狀病毒感染有關，或許不能反映在診所診視的個案，但由住院、急診和門診病人陽性率的差異，推測社區診所病人的感染率可能較低。

　　　　　Objectives: This report described the prevalence and clinical characteristics of rotavirus infection among children aged 5 years and younger with acute gastroenteritis receiving cares at four medical centers in Taiwan. Methods: The surveillance data from April 2001 and October 2002 for childhood gastroenteritis, obtained from the Center for Disease Control, Department of Health, Executive Yuan were used to calculate counts and rates among inpatients, emergency patients, and outpatients. Results: Among 2477 gastroenteritis cases, there were more inpatients (74.8%) than emergency patients (22.3%) and outpatients (2.9%). Most reported children (65.2%) were between 6 to 36 months of age with a peak shown between 6 to 11 months of age (20.6%). Rotavirus was the predominant pathogen (43.6%) with the prevalence rate being higher for inpatients (47.1%) than for emergency patients (33.9%) and outpatients (28.8%). Inpatients were also more likely than others to have infections of bacteria (11.7%), adenovirus (2.9%), or dual types of pathogen (4.5%). Patients with rotavirus infection were likely to have diarrhea (93.7%), fever (63.9%), and dehydration (54.8%). These symptoms were also more prevalent in inpatients than in other patients. Conclusion: In infants and young children with acute gastroenteritis receiving care at medical centers are more likely to have the rotavirus infection, particularly for inpatients. We also speculate that the rotavirus infection is relatively low among gastroenteritis patients being cared for by community physicians.