台灣外籍勞工之人芽囊原蟲基因型研究

Molecular Subtyping of Blastocystis Hominis Among Immigrant Workers in Taiwan

人芽囊原蟲（Blastocystis hominis）是人類常見的腸道原蟲。在開發國家中有很高的盛行率。本研究中收集了印尼、泰國、菲律賓、越南的外籍勞工各200位糞便檢體，共800位檢體。檢體皆進行寄生蟲檢查，結果中115名（14.4%）有腸道寄生蟲感染，其中111位感染人芽囊原蟲。人芽囊原蟲基因分型中，最常見的基因型為ST3，於各個國家中都有發現，其次為ST1。ST2僅在印尼和菲律賓發現。ST5，ST6和ST7則零星的在不同國家發現。演化樹分析中，ST3序列和人類感染株有高度聚集。部份ST1和ST2序列也與紅毛猩猩和豬源感染的序列有高的親源性，顯示有些人芽囊原蟲序列與動物感染有密切相關。顯示部份人類與動物的感染可能源自於共同的感染來源。未來需要更多衛生教育與人員管理，將可減少人芽囊原蟲散播與感染。

Blastocystis hominis is one of the most common intestinal protozoans in human. The prevalence of Blastocystis hominis infection is higher in developing countries. We collected 800 stool samples among immigrant workers coming from Indonesia, Thailand, Philippines and Vietnam. Two hundred stool samples were collected from immigrant workers of each country. All stool samples were examined by microscopy on suspicion of parasitosis. A total of 115 immigrant workers (14.4%) were positive for intestinal parasitic infection. Among them, 111 immigrant workers (13.9%) had Blastocystis hominis infection. In Blastocystis hominis subtype analysis, 65 workers were positive for subtype (ST) 3, which is the most common genotype and could be found in immigrant workers from each country. The following common subtype is ST1, 23 workers were positive for ST1. ST2 could only be found in immigrant workers from Indonesia and Phillippines. ST5, ST6 and ST7 were sporadically found among immigrant workers from different countries. In phylogenetic analysis, the ST3 was highly similar to other human isolates. ST1 and ST2 sequences appeared to highly related to isolates from Pongo pygmaeus and pig origin infection. The study demonstrated that some of Blastocystis hominis found in humans were closely related to animals. Public health education and proper management may help to reduce Blastocystis hominis transmission.