« Back to Articles for Therapists Parasites: Categories And Life Stages by Jane Thurnell-Read Here's a short introduction to the wonderful world of parasites. A parasite is "any organism living in or on any other living creature and deriving advantage from doing so, while causing disadvantage to the host" BMA Complete Family Health Encyclopaedia Parasites are commonly acquired by eating contaminated meat, swallowing eggs on food, contaminating fingers with faecal material or through contact with infected water. CATEGORIES OF PARASITES Parasites are divided into the following categories: 1. FLATWORMS (also called platyhelminths) a) tapeworms (also called cestodes) b) flukes (also called trematodes) 2. ROUNDWORMS a) threadworms b) pinworms c) hookworms LIFE STAGES OF PARASITES The different categories of parasites go through different life stages. Tapeworms: egg becomes larva, which becomes encased by body in a cyst, which becomes adult Fluke: egg becomes miracidia, which becomes redia, which becomes cercaria, which becomes metacercaria, which becomes adult Roundworms: egg becomes larva, which becomes adult We sell two parasite test kits. You can get more information on Parasite 1 and Parasite 2 Test Kit and order online.