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Parasitic Diseases: Often Severe, Nearly Always Preventable
Many people, particularly in industrialized countries such as the United States, may think "parasites" and "parasitic diseases" are mysterious terms for illnesses that will never affect them. Parasitic diseases can also occur in the United States. For example:
- Cryptosporidium, a single-celled parasite found in the stools of humans, and a wide range of animals, can be transmitted by ingesting contaminated water or food. In the U.S., Cryptosporidium can cause isolated infections as well as community outbreaks of severe diarrhea, particularly in persons with decreased immunity.
- Parasites can be transmitted through contact with infected pets. The single-celled parasite Toxoplasma gondii, when acquired by pregnant women through contact with contaminated feces, may result in severe symptoms, such as blindness, in their babies.
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Accidentally swallowing contaminated recreational water is one way children can get cryptosporidiosis, a parasitic disease. |
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Parasites are present in the daily life of many people worldwide and cause disease that can severely affect individuals and societies alike. For example:
- Malaria, a mosquito borne disease caused by a single-celled parasite (protozoan) that infects red blood cells, kills one African child every 30 seconds.
- Intestinal worms (helminths) which measure from 1/2 inch to over 10 feet in length, depending on the species, represent one of the most frequent infections, affecting over 3 billion people worldwide. They are the major cause of anemia and delayed growth in children in tropical countries.
Many parasitic diseases in less developed countries are often due to poverty and lack of knowledge. For example:
- Chagas disease, a frequent cause of severe disease of the heart and digestive organs in South and Central America, is acquired when people sleeping in poorly built dwellings are bitten by kissing bugs (triatomids) infected with the single-celled parasite Trypanosoma cruzi. The bug lives in cracks in the walls and comes out at night to feed.
- Guinea worm disease, which can cause excruciating infections, most often of the feet, is acquired when people drink water containing small crustaceans (copepods) infected with the larvae of the worm Dracunculus medinensis, without filtering or boiling the water.
Fortunately, most parasitic diseases are preventable. For example:
- Transmission of foodborne and waterborne parasites (such as Cryptosporidium and many intestinal parasites) can be prevented by correct handling and treatment of food or water.
- Handwashing can help reduce the transmission of parasites from pets. If you are pregnant and own a cat, have another household member change the litter box.
- Many parasites go through a life cycle during which they are transmitted from one person to another through an animal vector, such as a mosquito or a snail. Removing the vector, or preventing contact between people and the vector, will break that life cycle and thus prevent transmission.
- Prevention is a key component in most of the international public health campaigns to control or eliminate parasitic diseases.
Related Parasitic Diseases
A to Z Index of Parasitic Diseases