Parasites, it is a kind of worm, that is, we will parasitize the human body, but also can parasitize animals. For example, the tapeworm of pork, as we call it in folklore, may manifest itself as a tapeworm in the body of a pig, and then if a person eats this pork, he or she may also have tapeworm. Of course, there are also larval cysticerci of the tapeworm, which may enter other organs. Clinically, we see a lot of cysticercosis, which is a very difficult disease to treat, and other parasites like roundworms and pinworms, which are all parasites in the human body. Of course, the parasites that we have in humans are called human parasites, and if we have parasites in other domestic animals, such as animals cattle, horses can have parasites. Then the human being is called the host and the worms in the human body are called parasites. These parasites may be damaging to the human body or they may coexist peacefully. Of course, the ones that are clinically relevant to our infectious diseases to us are the ones that are damaging to the human body. Roundworms, for example, may absorb nutrients from a person’s intestines and cause wasting. If the roundworms migrate to the biliary tract and leave the intestines, then there may be obstruction of the biliary tract, which may cause fever, jaundice, severe abdominal pain, and these symptoms. Like Schistosoma pneumoniae, for example, it can also get to the lungs and cause coughing and hemoptysis. Of course, we also have a few years ago, I heard that because of eating Fukushou snails infected with this Guangzhou tubular nematode, tubular nematode into the human brain will cause headache and fever these symptoms. All in all, parasites are those worms that live in the human body and cause damage to the human body, which is called parasitic disease.