There are a multitude of pathogens capable of infecting the human body and causing disease. This program explores the six main categories of pathogens: bacteria, viruses, fungi, protozoa, prions and macroparasites. Their structure, mode of transmission, and the changes they cause in the host are described. Real-life images, microscopic views of cells and pathogens, and animations make this an excellent resource for the study of pathogens and infectious disease