鏡檢與阿米巴物種分子鑑別診斷之差異及其對臨床實務與公共衛生監測意涵：以一例Entamoeba dispar感染者為例

Microscopy versus molecular identification of Entamoeba species and their implications for clinical practice and public health surveillance: a case of Entamoeba dispar infection

目標：本研究報告一例健康檢查中發現Entamoeba dispar感染個案，並探討其臨床與監測意涵。由於Entamoeba histolytica與Entamoeba dispar、Entamoeba hartmanni在鏡檢下形態相似，糞便鏡檢難以準確鑑別，可能導致誤分類與不必要治療。方法：回溯分析一名糞便鏡檢疑似阿米巴囊體但無症狀之個案，並以qPCR確認物種；另回顧本院近五年寄生蟲檢體資料，以及台灣CDC 2011至2025年年報病例數。結果：該個案為33歲女性，經qPCR確認為E. dispar。臨床僅給予衛教與追蹤。院內2020至2025年寄生蟲檢體陽性率介於0.16%至0.49%，多為非致病性原蟲。全國資料顯示，2011至2025年痢疾阿米巴病例數呈年度波動，通報數普遍高於確定病例數。結論：本案例凸顯鏡檢在阿米巴物種鑑別上的限制，以及分子檢測對臨床決策與監測資料判讀之重要性。結合鏡檢與qPCR之分層檢測策略，有助於提升診斷準確性、避免不必要治療，並增進監測資料之可信度。

Objectives: This study aimed to report a case of Entamoeba dispar infection detected during a routine health check and to discuss its implications for clinical practice and public health surveillance. Because Entamoeba histolytica, Entamoeba dispar, and Entamoeba hartmanni are morphologically similar under microscopy, stool microscopy alone is insufficient to distinguish these species. This may lead to misclassification and unnecessary treatment. Methods: We reviewed an asymptomatic patient with suspected amoebic cysts on stool microscopy and used quantitative polymerase chain reaction (qPCR) to confirm the species. We also reviewed 5 years of laboratory parasitology data and Taiwan Centers for Disease Control case data from 2011 to 2025. Results: The patient was a 33-year-old woman, and qPCR confirmed E. dispar. She received health education and clinical follow-up without antiparasitic treatment. In our laboratory, parasite positivity rates ranged from 0.16% to 0.49% during 2020 to 2025, and most positive findings were non-pathogenic protozoa. National data revealed annual fluctuations in confirmed amoebiasis cases from 2011 to 2025, and reported cases were generally higher than confirmed cases. Conclusions: This case highlights the limitation of microscopy in identifying Entamoeba species and the importance of molecular testing for clinical decision-making and interpretation of surveillance data. A stepwise strategy combining microscopy and qPCR may improve diagnostic accuracy, avoid unnecessary treatment, and improve the reliability of surveillance data.