There are two main groups of intestinal parasites: helminths and protozoa. Collectively, these organisms cause millions of infections around the world every year, in regions which vary from the urban United States to the remote areas of Africa. Left untreated, intestinal parasites can cause long term health problems or even death in the patient, and the patient can also act as a carrier to spread the parasites to other members of the community.
Intestinal parasites can be ingested in a variety of ways, with one of the leading modes of transmission being fecal to oral contact due to poor hygiene. Infections can also occur when parasites colonize water or soil, or in the case of zoonotic parasites which infect animals consumed by humans. In all cases, the parasites feed off the body to the detriment of the patient, interfering with nutrient absorption and causing a variety of symptoms.
People may develop symptoms right away, or they may be infected for years without being aware of it. When symptoms do appear, abdominal pain, nausea, vomiting, diarrhea, and cramping are all very common. The presence of intestinal parasites can be diagnosed with the use of a fecal sample which is examined for traces of organisms which could be causing infection. Patients should be aware that sometimes a sample may yield false negative or inconclusive results, necessitating another sample.
Helminths or worms are multi-celled organisms which are typically found in undercooked food, although it is also possible to be infected via contaminated water or soil. Tapeworms, roundworms, and pinworms are among the most famous and widespread. One of the classic signs of infection with worms is the presence of worms or segments in the feces.
Protozoa such as amoebas, giardia, and cryptosporidium are one celled organisms which can multiply freely in the intestinal tract. It can sometimes be difficult to identify protozoa because they are so small and difficult to identify in the feces. People who have traveled recently should alert their doctors to this fact when they request medical attention for symptoms which suggest infection with intestinal parasites, as travel is a major risk factor for infection.
Several medications can be used to eliminate intestinal parasites from the body. These drugs are generally available by prescription only to encourage patients to go to the doctor for a diagnosis so that the correct medication can be selected to eliminate the particular species causing the infection. Some patients also have success with herbal and other alternative therapies.