Parasites need a host to survive and spread. There are three main types, and their symptoms vary. Stay away from others if you have a parasite to prevent the spread.

Nov 14, 2024 · There are three main classes of parasites that can cause disease in humans: protozoa, helminths, and ectoparasites. Protozoa are microscopic, one-celled organisms that can be free-living …

Parasitism is a kind of symbiosis, a close and persistent long-term biological interaction between a parasite and its host. Unlike saprotrophs, parasites feed on living hosts, though some parasitic fungi, …

Nov 24, 2025 · Parasites live in other host organisms and depend on them for survival. Parasites can spread diseases and cause parasitic infections. The symptoms of a parasite infection in humans can …

Aug 18, 2025 · We asked experts how parasites are transmitted, what it feels like to be infected, and what you can do to protect yourself.

Oct 14, 2025 · It is estimated that 3 out of 5 Americans will be affected by parasites at some point in their lives. Learn about the various types of parasites, symptoms, and the sources of infection and …

5 days ago · Executive summary Common human parasitic infections produce a predictable cluster of symptoms—primarily gastrointestinal distress, unexplained itching (especially perianal), fatigue and …