His research began with fruit flies, but over the last two decades, his focus has been on parasitic protozoa, single-celled organisms that cause major diseases.

VOA: standard.2010.04.05

Parasitic organisms like protozoa and worms which are - which can cause terrible diseases.

而某些寄生生物,如原生动物和蠕虫,可以引起严重疾病

耶鲁公开课 - 生物医学工程探索课程节选