Intestinal parasites

Intestinal parasites are parasites that populate the gastro-intestinal tract in humans and other animals.[1] They can live throughout the body, but most prefer the intestinal wall. Means of exposure include: ingestion of undercooked meat, drinking infected water, and skin absorption. The two main types of intestinal parasites are helminths and protozoa. An intestinal parasite can damage or sicken its host.

The major groups of parasites include protozoans (organisms having only one cell) and parasitic worms (helminths). Of these, protozoans, including cryptosporidium, microsporidia, and isospora, are most common in HIV-infected persons. Each of these parasites can infect the digestive tract, and sometimes two or more can cause infection at the same time.


Parasites can get into the intestine by going through the mouth from uncooked or unwashed food, contaminated water or hands, or by skin contact with larva infected soil, they can also be transferred by the sexual act of anilingus in some cases. When the organisms are swallowed, they move into the intestine, where they can reproduce and cause symptoms. Children are particularly susceptible if they are not thoroughly cleaned after coming into contact with infected soil that is present in environments that they may frequently visit such as sandboxes and school playgrounds. People in developing countries are also at particular risk due to drinking water from sources that may be contaminated with parasites that colonize the gastrointestinal tract.


A list of common symptoms:[2]

  • Abdominal pain
  • Hemoptysis
  • Dysuria
  • Central nervous system impairment
  • Chest pain
  • Chills
  • Chronic fatigue
  • Colitis
  • Coughing
  • Diarrhea
  • Digestive disturbance
  • Dizziness
  • Fever
  • Enlargement of various organs
  • Headaches
  • Vaginitis
  • Jaundice
  • Joint pain
  • Weight loss due to malnutrition
  • Weakness
  • Immunodeficiency
  • Nausea/vomiting
  • Swelling of facial features
  • Sweating
  • Insomnia
  • Skin ulcers
  • Rectal prolapse
  • Mental problems
  • Lung congestion
  • Memory loss
  • Night sweats
  • Muscle spasms
  • Hair loss or thinning

In some people, intestinal worms do not cause any symptoms, or the symptoms may come and go. If you have some of these symptoms, it does not necessarily mean that you are infected. These symptoms are also indicative to other diseases.

Common signs and complaints include coughing, cramping, abdominal pain, bloating, flatulence and diarrhea. Some parasites also cause low red blood cell count (anemia), and some travel from the lungs to the intestine, or from the intestine to the lungs and other parts of the body. Many other conditions can result in these symptoms, so laboratory tests are necessary to determine their cause.

In children, irritability and restlessness are commonly reported by parents.


Due to the wide variety of intestinal parasites, a description of the symptoms rarely are sufficient for diagnosis. Instead, two common tests are used: stool samples may be collected to search for the parasites, and an adhesive may be applied to the anus in order to search for eggs.


Prescription drugs are generally used to eradicate the parasites. Special poisons are tailored to kill one or more common varieties of intestinal parasites. Good hygiene is recommended to avoid reinfection.

The Rockefeller Foundation's hookworm campaign in Mexico in the 1920s was extremely effective at eliminating hookworm from humans with the use of antihelmintics. However, preventative measures were not adequately introduced to the people that were treated. Therefore, the rate of reinfection was extremely high and the project evaluated through any sort of scientific method was a marked failure. More education was needed to inform the people of the importance of wearing shoes, building latrines, and good hygiene.[3]

See also


  • Zuk, Marlene. Riddled with Life. Orlando, Florida: Harcourt, Inc 2007
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.