给出一篇英文文章，要求GPT模型将其重写为简化版英语。


Parasites are organisms that live in or on another organism, called a host. The parasite benefits from the relationship, while the host is harmed. There are many different types of parasites that can infect humans, including roundworms, tapeworms, and lice. These parasites can cause a variety of health problems, ranging from mild irritation to serious illnesses like malaria and sleeping sickness.
Parasites are creatures that live on or inside another creature, which is called the host. The parasite gets advantages from this association, while the host is negatively affected. There exist various types of parasites that can infect people, including roundworms, tapeworms, and lice. These parasites can lead to several health issues, starting from minor irritation to severe illnesses like malaria and sleeping sickness.