What Are Parasites?

Parasites are living organisms that obtain food and shelter from other living things. Parasites live in and on people, animals or plants. There are many different kinds of parasites. Some, like dog or cat fleas, are large enough to be seen without a microscope and others are so tiny they can only be seen with a microscope.

Some microscopic parasites cause disease but there are others that do not. It is hard to be sure that these organisms mentioned here are the causes of illness and experts often disagree on this point. These usually non-pathogenic (do not cause disease) parasites do not require treatment unless all other possible causes have been ruled out. Diagnosis of these parasites is done by stool culture and they can be difficult to find. A person may be shedding the parasite on one day, but not on the next day. If the sample is taken on the first day there is a good chance the lab would find it but if the sample were taken on the second day it would be impossible.

A person can have more than one parasite at a time, but they may not all be present in one stool sample. It is suggested that a person submit one stool sample on each of three consecutive days to get a representative sample of what is in their bowel. The Symptoms you are experiencing may be caused by other parasitic organisms, bacteria, or viruses. Often non-pathogenic parasites are found along with other organisms that are more likely to be the cause of your symptoms.

Dientamoeba fragilis (DYE-ent-a-ME-ba fra-JILL-us)

This organism is most likely transmitted with pinworm eggs. Children are most frequently infected by Dientamoeba fragilis. This organism has possible symptoms of vague abdominal pain, bloating, diarrhea, loss of appetite, fatigue and weight loss; but more frequently there are no symptoms at all. It is very likely that a child positive for Dientamoeba fragilis will have or have had an infection of pinworm.

Blastocystis hominis (BLASS-toe-SIS-tiss HOM-in-iss)

This organism is usually transmitted through contaminated water. Symptoms associated with this organism are watery or loose stools, diarrhea, abdominal pain, gas and vomiting. Many people do not develop any symptoms at all. Blastocystis hominis can remain in the intestines for weeks, months, or years. The frequency of infections with Blastocystis hominis increases in areas where sanitation and personal hygiene is inadequate therefore thorough hand washing practices are essential to protect yourself.