Parasitophobia is the fear of parasites. Sufferers would think that there are parasites in them even though they don't notice it. The most fearful parasite would be worms, called tapeworms. A branch of parasitophobia that only fear tapeworms is called teniophobia. Parasitophobes are afraid that parasites may affect their bodies to the point of having diseases or even death. Sufferers believe that many diseases are caused by parasites in them, so parasitophobes often suffer pathophobia (fear of diseases) too.
Sufferers would constantly have obsessive thoughts about parasites in them, detaching from reality. They may have rapid heartbeat and rapid breathing. Some may limit sleeping as there's risk that parasites may unpleasantly influence the body of the host while asleep.