Types of Parasites

A parasite is an organism that lives in or on a host organism and depends on the host for food. While parasites benefit, the host usually gains nothing and often will suffer from infection or disease. There are thousands of different types of parasites. The following is an overview of the basic categories into which parasites can be placed.

Protozoa

The protozoa parasites are single-celled organisms. They can attack any single cell, and they duplicate themselves in your body in the same way a virus or bacteria do. These parasites can be found in the blood, nervous system and genitals. A well-known disease caused by a blood parasite is malaria. Tuberculosis is also caused by a blood parasite that lives in the white blood cells. The different species of protozoa can enter your body in different ways. They can be transmitted by insects or through water. There are also a variety of blood parasites that can enter your body through infected, undercooked meat.

Roundworms

These are parasitic worms that can make their way into your body as eggs when you eat infected and undercooked meat, especially pork. Roundworms can also be ingested in infected water. They hatch and live in the intestines of their host, steal ing food and nutrients. Roundworms are either pink or white in color. The largest known species of roundworm that infects humans, can grow to fifteen inches. The most common of the roundworms are pinworms, hookworms and whipworms.

Tapeworms

These parasitic worms are flat and have segmented bodies. Tapeworms are also contracted by eating undercooked, infected meat. This type of worm lives in the intestinal tract of its host, using its head to hook into the walls of the intestine. Each segment of the tapeworm can self-fertilize, and the segments can break off and move to other parts of the host's body, or leave the body to infect another host. The tapeworm can regenerate even if only the segment containing the head is left. The most common tapeworm is the pork tapeworm. The largest species of tapeworm is the fish tapeworm, which can grow to be 33 feet long. Tapeworms are a grayish-white color.

Flukes

The flukes are a type of parasitic worm that are oval-shaped but flat. Flukes can be found in various organs of their host, such as the liver or lungs, and can also inhabit the blood. The blood flukes travel through different organs in the body, and they are especially dangerous because they can infect the brain and spinal cord. Flukes most commonly are contracted by eating undercooked water plants or raw fish. However, you can also ingest them from various undercooked meats or unwashed vegetables. Some flukes enter humans by burrowing into the host's skin.

Arthropods

This category of parasites includes those that are insects. The common insect parasites are fleas, lice, ticks and mites. These parasitic insects attach to a host animal or human and can carry devastating diseases with them. These parasites infect you by either burrowing into your skin, as mites do, or by drinking your blood, like lice and ticks.