台灣地區豢養動物糞便檢體中隱孢子蟲存在情形之檢測

Occurrence of Cryptosporidium in the Fecal Specimens of Feeding Animals in Taiwan

隱孢子蟲（cryptosporidium）是一種能寄生在脊椎動物腸道的原生動物。近年全球已有多起隱孢子蟲所引起的大規模感染案例。人類感染隱孢子蟲的原因包括直接接觸以及吃到受污染的食物或飲水，而水源受污染是隱孢子蟲症流行的主要因。本研究選擇國內五處採樣點，以酵素鍵結免疫呈色分析法（enzyme－linked immunosorbent assay；ELISA）、非直接免疫螢光抗體法（indirect immunofluorescence assay；IFA）以及磁性抗體分離法（immunomagnetic separation；IMS）檢測隱孢子蟲於牛、豬、雞、鴨等豢養動物糞便檢體中之存在情形。結果顯示，鴨感染率為85.4％、豬的感染率為30.4％、牛的感染率為25.0％。至於雞的糞便檢體則未檢測出隱孢子蟲。使用ELISA法檢測隱孢子蟲而抗體呈陽性反應之樣本，經IMS處理及IFA染色後，未必能在螢光顯微鏡下觀測到隱孢子蟲，兩者相關性並不佳。以IFA對糞便檢體染色後，用螢光顯微鏡觀察樣本過程中會受雜質干擾，因此IFA進行染色前，樣本最好先以IMS處理，以降低干擾。

Cryptosporidium have been recognized as a common pathogenic protozoa of the gastrointestinal tract of many vertebrates. Many outbreaks of human cryptosporidiosis have been reported in the last few decades. Human infection with these pathogens is usually through either direct contact or ingestion of contaminated food and/or water. Water is perhaps the major source for massive outbreaks of infection, as a result of contamination of source water. In this study, we chose five sampling area in Taiwan and detecting Cryptosporidium using ELISA, IMS/IFA methods. The detected fecal specimens of feeding animals included cattle, pigs, chickens, and ducks. Results showed that the positive rates of containing Cryptosporidum antibodies in the samples were 85.4% for ducks, 30.4% for pigs, 25% for cattle, respectively. There were no Cryptosporidium antibodies detected in the fecal specimens of chickens. The positive samples identified by the ELISA method was then analyzed by the IMS/IFA methods. The results showed that the correlation between ELISA and IMS/IFS methods is not Significant. While fecal specimens stained with IFA directly, the observation results Will be interfered with debris. It is suggested that samples need to be pretreated with IMS while staining by IFA.