Opportunistic Infections: Toxoplasma, Sarcocystis, and Microsporidia will focus on two important Genera of Apicomplexan parasites, Toxoplasma gondii and Sarcocystis species, and the medically important members of the Phylum Microsporida. We have been fortunate in obtaining excellent contributions from many experts in the field. Volumes in the World Class Parasites book series are written for researchers, students and scholars who enjoy reading about excellent research on problems of global significance. Each volume focuses on a parasite, or group of parasites, that has a major impact on human health, or agricultural productivity, and against which we have no satisfactory defense. The volumes are intended to supplement more formal texts that cover taxonomy, life cycles, morphology, vector distribution, symptoms and treatment. They integrate vector, pathogen and host biology and celebrate the diversity of approach that comprises modern parasitological research.