What Are The Most Common Parasitic Infections?


Number of parasites that can live on humans
Number of parasites that can live on humans

What is a parasite?

A parasite is an organism that lives in or on another organism. In addition to being either unicellular or multicellular, they can also be either plant or animal based.

How many parasites are there that can infect humans?

There are over 430 known species of parasite that can infect the human body.

What are the most common parasitic infections?

The two most common parasitic infections are malaria and toxoplasmosis.  Below is a list of some of the more common parasites that can infect humans.


Toxoplasma gondii is a parasitic infection that occurs as a result of the infection of the parasite. When a healthy person contracts the parasite, they may experience flu-like symptoms, but it can be deadly to individuals with weak immune systems, such as those who have HIV/AIDS or cancer.


Malaria is the most common parasitic infection in humans. Plasmodium is a parasite that results in malaria and mosquitoes are the main vectors for the transmission of this disease. Fever, chills, and anemia are some of the more common symptoms of malaria.


The term “mites” refers to the tiny parasites on the body of humans. Mites are usually found on the scalp and in the hair as well as in the eyebrows. Around the world there are more than 2,000 different types of mites that exist. A common type of mite is ear mites, they commonly infect the ears of dogs and cats, but can also infect human ears.

An infection caused by mites in humans is commonly referred to as scabies. Scabies is a skin condition that can cause redness of the skin, itchiness and occasionally fever. There is a very high risk of transmission of scabies through direct contact with the infected person or by direct contact with their belongings.


The flea is a parasite that lives on the bodies of mammals and birds. This parasite feeds exclusively on the blood of its hosts. Known as an obligate parasite of mammals and birds, the common flea is found in temperate regions around the world, where its primary hosts are rodents and pets.

The flea is a wingless insect that is laterally compressed in shape. It has powerful hind legs that can jump high into the air, and a long proboscis in which to suckle blood from its host. The flea is a member of the order Siphonaptera.

Head Lice

Those who suffer from head lice are infested with parasitic insects, which feed on the blood of humans. Head lice are very common, especially among children.

It is quite common to find head lice anywhere in the world, but they are more common in humid climates. Being incapable of jumping or flying, they have to live close to their hosts and move their way around by crawling.


Tapeworms are a parasite that lives in the intestines of its host and feeds of the food that the host eats. to learn more about these gross parasites head over to our Tapeworm page.