Examples Of Parasitism

Parasitism examples range from annoying mosquitos that bite you when you’re outside to fleas and ticks biting dogs to fungi attached to trees and barnacles living on a crab’s shell.

By definition, parasitism is where the parasite lives in (or on) a host and causes harm to the host. This can occur in plants, animals, and even insects and can cause a significant amount of damage, possibly killing its host. Check out this guide to learn all about parasitism.

Many diseases including malaria, dengue, meningitis – just a few examples – these are what we call climate-sensitive diseases, because such climate dimensions for rainfall, humidity and temperature would influence the epidemics, the outbreaks, either directly influencing the parasites or the mosquitoes that carry them. – Margaret Chan

What Is Parasitism?

When you think about parasitism you more than likely think about parasites. According to Dictionary.com (found here), a parasite is:

an organism that lives in or on another organism (its host) and benefits by deriving nutrients at the host’s expense

Parasites can be any kind of organism such as worms, parasitic bugs, and even humans. The host of the parasites can be seriously affected and at times can even die. A majority of all the parasitic organisms in the world cannot be seen by the human eye, making their threat to a host somewhat concerning. An important thing to note is that parasites are not a “disease”, even though the symptoms of having a parasite might look like some sort of disease.

Types And Examples Of Parasitism

There are three primary types of parasites:

  • Ectoparasites
    • These parasites live on the host
    • Includes lice, fleas, ticks, etc.
  • Protozoa
    • These parasites are single-cell organisms that live inside the host
    • Examples include Plasmodium, Balantidium, etc.
  • Helminths
    • These are worm parasites (they can reside in their host’s intestines, heart, etc.)
    • Includes roundworms, hookworms, heartworms,

Let’s go over some examples of parasitism now.

Symptoms Of Parasitism

Parasites can oftentimes have symptoms that mimic diseases, which makes them difficult to narrow down if someone is sick of has a parasite.

Some general symptoms of parasites include:

  • Fever
  • Rashes
  • Diarrhea, vomiting, stomach ache
  • Insomnia
  • Suppressed appetite
  • Muscle weakness

There are also times when there are no symptoms, so many people don’t know that there is some sort of parasitic infection.

Parasitism Examples

A mosquito is an example of an ectoparasite. Image source: Pixabay

Protozoa Parasitism Examples

These are the single-cell parasites that can affect living organisms. Examples are:

  • Plasmodium Falciparum, also known as Malaria
    • This parasite is the cause of malaria, the blood disease that has affected many people in tropical regions. Malaria symptoms are fever, vomiting, drowsiness, and can even lead to death. It is spread primarily by mosquitos that introduce the parasite into the host’s body.
  • Balantidiasis, also known as B Ecoli
    • This parasite primarily affects pigs, but it has been known to infect humans as well. This parasite infects the intestines and can cause diarrhea or constipation. This is spread by drinking water or eating contaminated food.
  • Acanthamoebiasis
    • This single-cell parasite is found all across the globe and affects the skin, brain, and even the host’s eyes. This parasite can be found in water and soil. The primary way to get this is if you clean your contact lenses with tap water instead of a contact solution.
  • Coccidiosis
    • This parasite lodges itself in its host’s intestines that can cause severe diarrhea (which can be bloody). This can affect humans, cats, dogs, and other animals. It is spread through contact with infected tissue or with feces.
  • Primary amoebic meningoencephalitis, also known as PAM
    • This is quite possibly one of the nastier parasite examples found on this list. This parasite affects the brain and the nervous system, killing its host within a matter of 1 day to about 2 weeks. The spread of this parasite is pretty interesting (and scary); if someone breathes in near a contaminated site, such as a swimming pool or soil, they oftentimes become infected. This is not spread, however, from drinking water.

Helminth Parasite Examples

Helminth parasites are worm parasites that can infect humans and animals. If you are a pet owner you are probably familiar with a few different helminth parasites.

  • Roundworm
    • Roundworms are the most common parasites a dog can get. These guys burrow into our dogs’ intestines and are spread by eating or drinking anything that has been contaminated. Oftentimes our pooch won’t show symptoms except for finding worms in their feces. Roundworms are often preventable by keeping your pet on heartworm medication and keeping their environment clean.
  • Dirofilaria immitis, also known as heartworms
    • Speaking of heartworms, this is a parasite you are probably very familiar with. Heartworms can affect dogs, cats, horses, humans, and many other mammals, and they can be fatal if untreated. Heartworms are 12 inch long works that reside in your pet’s hearth, blood vessels, and even their lungs. This causes severe heart problems as well as other diseases. A way to prevent heartworms is to keep your pet on heartworm pills. If your pet does have heartworms it can be treated with the use of heartworm prevention medication.
  • Whipworm
    • This worm lives in the large intestine and can affect humans. Its larva is spread through poop (and unwashed fruits and veggies) and is found all over the world.

Ectoparasite Examples

Lastly, these parasites live on their hosts and can affect different kinds of living organisms. You can expect to find ectoparasites feeding off of humans, animals, and plants.

  • Phthiraptera, also known as lice
    • We all remember lice from school, right? Lice live off of sucking their host’s hair and pulling nutrients from it, as well as our scalps. There are three types of lice that humans can harbor: body lice, head lice, and pubic lice. Lice can be treated with special shampoo and lice combs.
  • Mistletoe
    • What we often associate with Christmas festivities is actually a parasite. Mistletoe attaches to a host tree and leeches out water and nutrients from it. This can lead to the host tree dying. Interestingly enough, there are many animals who eat mistletoe as part of their diet, and that is how mistletoe is spread to other trees and shrubs.