Javatpoint Logo
Javatpoint Logo


Parasitism is a species-to-species symbiotic relationship in which one organism, the parasite, lives on or within another. This article gives a complete overview of the parasite and its types, symptoms, causes, treatment, risk factors, and prevention.

What is the parasite?

A parasite is an organism that lives in or on other organisms and gets its food from or at the expense of its host. A parasite is a type of organism that lives on or in an organism of another species that absorbs nutrients. In certain cases, the parasite can damage the host, and in other instances, the parasite is fully harmless.

Parasites normally benefit from such partnerships, even at the detriment of host species. Human parasites contain protozoans, helminths, and ectoparasites. We cause many diseases and are generally transmitted to their hosts by ingestion of infected food or water or by the bite of an arthropod, which may serve as both an intermediate host and a vector.

Parasitic symbiosis

It refers to a long-term relationship between two separate organisms. In certain cases, all organisms benefit from cooperation, which is known as mutualism. The larger organism is known to be a host because it is also the larger organism on which the smaller organism depends in a symbiotic relationship. The smallest organism that lives inside the host is known as the symbiont.

Parasitism is the form of a symbiotic relationship or long-term relationship between either plants or animals of any two species. The parasite makes a profit from the host, which causes the host to hurt without killing him.

Symptoms of Parasite

Various symptoms of parasitic infections vary on the organism. These can sometimes be similar to the symptoms of other conditions, including hormone deficiency, pneumonia, food poisoning, and many others. Various symptoms of the parasite are as follows:

  • Anemia
  • Fever
  • Abdominal pain and diarrhea
  • Allergies
  • Weight loss and increased appetite
  • Sleeping problems
  • Skin bump and rashes
  • Aches and pains

Types of parasitic infections

There are mainly three types of organisms that may cause parasitic infections:

  1. Protozoa
  2. Helminths
  3. Ectoparasites


Protozoa are a single-celled organisms that can divide only within a host organism. Some protozoa-caused infections include giardiasis. It is a severe infection that we may contract from Giardia protozoa-infected drinking water.


Helminths are multi-celled organisms that are able to live in the body or outside it. Generally, they're known as worms. It includes thorny-headed worms, roundworms, Flatworms, and tapeworms.


Ectoparasites are multicell organisms that the skin lives on or feeds off. It may include some insects, like ticks, mites, mosquitos, and fleas.

Parasitic infections can be transmitted in various ways, such as polluted water, food, waste, soil, and blood may spread protozoa and helminths. Some parasites are transmitted by insects, which serve as the disease's vector or carrier.

Human Parasites

Various types of parasites can affect humans. Some examples of parasites are as follows:


This tiny ameba may affect the skin, the brain, and the eye. It occurs in water and soil all over the world. People may become infected if they clean their contact lenses with tap water.


Balantidium coli is a single-cell parasite that normally infects pigs but can cause intestinal infection in humans in rare cases. It can be transmitted, typically in tropical areas, by direct contact with pigs or drinking polluted water.


It is affecting the intestines. The blastocysts, through the fecal-oral route, enter humans. A person may contract the parasite by consuming food or drink contaminated with human or animal feces containing the parasite.


The Entamoeba histolytica parasite causes it. It affects the intestines. It's common in developing countries with dense populations and poor sanitation. The fecal-oral route transmits it.


It is caused by Cystosospora belli, formerly known as Isospora Belli. It affects the epithelial cells of the small intestine. It is a worldwide phenomenon that is both treatable and preventable. It is transmitted along the fecal-oral route.

Sleeping sickness

It is caused by the Trypanosoma parasite, which the testicular fly transmits. It affects the central nervous system, lymph, and blood. It induces sleep behavior changes, among other symptoms, and is considered fatal if left untreated. It can pass through the placenta and affect a fetus during pregnancy.


It is a parasitic disease that belongs to the Leishmania family. It may affect the mucous membranes of the nose, mouth, viscera, skin, and throat. It can be lethal, and sandfly forms pass on the parasite.

Risk of parasitic infections

A parasitic infection can happen to anyone. But some peoples are at higher risk of infection than others. We're more likely to become infected with a parasitic infection:

  • If anyone has a weak immune system or sick with another disease already, the cause of parasitic may increase.
  • Work in childcare frequently works with dirt or work in other contexts where you routinely contact feces.
  • Lack of a clean supply of potable water.
  • Swim in lakes, ponds, and rivers where Giardia is prevalent or other parasites.

How do we diagnose parasitic infections?

Parasitic infections may be diagnosed in several ways. For example, the doctor may perform some tests or order:

  • Blood test: The doctor may advise checking the blood test.
  • A fecal exam: A sample of the stool will be extracted and tested for parasites and their eggs in such types of tests.
  • X-ray, computerized axial tomography (CAT), and magnetic resonance imaging (MRI): These all are used to see the symptoms of lesions or injuries to the organs caused by parasites.
  • Endoscopy or Colonoscopy: It is used to find the parasite infection that may cause cramping, diarrhea, flatulence, watery stools, and many abdominal illnesses. This test is conducted when stool tests fail to show the cause of diarrhea. The doctor will move a thin, flexible tube through the mouth or rectum and into the digestive system when you are being sedated to examine the intestinal tract.

Treatment of Parasite infection

Once we know what type of parasite infection we have, we may choose how to treat it. Many parasite infections disappear its own if we eat a balanced diet and our immunity system is healthy. The doctor will usually prescribe oral medicine for those parasite infections that do not go away on their own. It is usually affected and has been proven to work.

It is generally possible to treat parasitic infections with antiparasitic drugs. The drugs given to whole populations to combat hookworm infection have been Albendazole and mebendazole. Pyrantel pamoate has been another drug administered to kill worm infections. There is no treatment for many parasite diseases, and in the case of serious symptoms, a drug intended to kill the parasite is administered. In contrast, symptom relief options are used in other cases. Recent papers have also suggested the use of viruses to treat protozoa-caused infections.

Prevention of Parasite infection

There are various steps we may take to reduce the risk of a parasitic infection. Some of them are as follows:

  • If you're driving, drink clean water, like bottled water.
  • If you're pregnant, avoid feces and cat litter.
  • Wash the hands regularly, especially before taking the food.
  • Stop swallowing lakes, streams, or ponds of water.

Next TopicReproduction

Youtube For Videos Join Our Youtube Channel: Join Now


Help Others, Please Share

facebook twitter pinterest

Learn Latest Tutorials


Trending Technologies

B.Tech / MCA