What is a parasite?

Parasites:

Parasites are organisms that live either inside or outside the host and depend on the host for their growth, multiplication, and survival.

Three types of parasites are:

1. Protozoa: They are single-celled microorganisms that can replicate inside the human body. If the protozoa reside inside the intestine, they can transmit the disease through contaminated food, water, or physical contact with an infected person. If the protozoa reside in blood or tissues, an arthropod vector is required for transmitting the disease. For example, Entamoeba histolytica and Plasmodium malariae.
2. Helminths: They are worms that fix themselves in the gastrointestinal tract and can be seen with the naked eye. They do not multiply in the human body. For example, tapeworms.
3. Ectoparasites: They reside outside the human body such as on the skin surface. For example, lice, ticks, and mites.