The stages of Blastocystis have been known for 101 years. However, many facts are still disputed, e.g. even the question whether it is a true pathogen or a commensal present in sometimes life-threatening diarrheas.

The present book evaluates in chapters contributed by renowned researchers the latest findings on:

- Landmarks in the discovery of Blastocystis

- Epidemiology, transmission and zoonotic potential

- Morphology of human and animal Blastocystis isolates

- Clinical aspects of Blastocystis infections

- Behavioral decision analysis: what makes us sick?

- Blastocystis-host interactions

- Molecular approaches on the systematical position

- Genetic polymorphism

- Blastocystis from a statistical point of view

- Diarrheas due to different agents of disease

- Zoonotic diseases in comparison

As such, this book provides a broad range of information for people working in this field, for physicians and veterinarians who are confronted with clinical cases, teachers, students and technical staff members in the fields of microbiology, parasitology and diagnostic methods.

Prof. Dr. Heinz Mehlhorn, Düsseldorf, Germany. He has investigated the transmission pathways of human and animal parasites for over 40 years and his university spin-off company Alpha-Biocare has developed various antiparasitic medical products based on more than 20 patents. He has published 25 books, more than 250 original papers, and has served as Managing Editor of the journal Parasitology Research since 1981.

Prof. Dr. Kevin SW Tan, Singapore , former fellow at the Rockefeller University. He is a specialist for molecular parasitology research in the fields of Blastocystis hominis and Plasmodium falciparum , and has received various national and international awards as well as considerable research grants for his work to date. More recently, he has funneled the research output of his many publications into the foundation of the company Biolynx Technology.

Prof. Dr. Hisao Yoshikawa, Nara, Japan. He has been an active researcher in many fields of medical and zoological parasitology for over 30 years. Over the course of this time, he has intensively studied the ultrastructure, cell biology and molecular phylogeny of many isolates of Blastocystis .