Parasites include single-celled protozoans such as the agents of malaria, sleeping sickness, and amoebic dysentery; animals such as hookworms, lice, mosquitoes, and vampire bats; fungi such as honey fungus and the agents of ringworm; and plants such as mistletoe, dodder, and the broomrapes.

Learn about parasites, their causes, diagnosis, and treatment from the Centers for Disease Control and Prevention (CDC). Find out how to protect yourself and others from parasitic infections, especially malaria, chagas disease, and neglected tropical diseases.

Parasites that can affect humans include ticks, lice, and hookworms. Symptoms of a parasite infection in humans can vary widely. Without a host, a parasite cannot live, grow, and multiply.

Three types of parasites can cause disease in humans. They are protozoa, carried by mosquitos, helminths, such as roundworm, and ectoparasites, for instance lice and bed bugs.

Parasitic infections often cause intestinal illness, with symptoms like diarrhea and vomiting. But they can also give you itchy skin rashes or infect other parts of your body, like your brain or lungs.

A parasite is an organism that lives on or in a host organism and gets its food from or at the expense of its host. There are three main classes of parasites that can cause disease in humans: protozoa, helminths, and ectoparasites.

Parasites are organisms that infect other living things to survive, live, feed, and reproduce on or inside them. Many types of parasites affect humans. In fact, these organisms can spread...

Learn about intestinal parasites, which are organisms that live in your gut and cause various health problems. Find out how they spread, what are the common types, and how to prevent and treat them.

At a glance. Animals, blood, food, insects, and water can transmit parasites. Animals (Zoonotic) Pets can carry parasites and pass parasites to people. Proper handwashing can greatly reduce risk. A zoonotic disease is a disease spread between animals and people. Zoonotic diseases can be caused by viruses, bacteria, parasites, and fungi.