Parasites are organisms that live inside humans or other organisms who act as hosts. They are dependent on their hosts because they are unable to produce food or energy for themselves. Parasites are harmful to humans because they consume needed food, eat away body tissues and cells, and eliminate toxic waste, which makes people sick.
Because of sanitary living conditions in America, parasites do not cause widespread life-threatening infections. In other parts of the world, however, parasitic infections are epidemic. They kill and disable millions of people every year. Parasitic infection cases in the United States are on the rise due to increased travel to and from underdeveloped countries. In addition, parasitic infections can cause severe infections in AIDS patients and other patients with weakened immune systems.
Because parasites can live inside the human body for years without making their presence known, they are more common than one might think. According to a recent study, approximately half of all Americans have at least one form of parasite. Their presence causes a variety of chronic diseases and conditions such as chronic fatigue, weakness, low energy levels, skin rashes, pain, constipation and frequent colds and influenza.
There are two types of parasites: large and small. Large parasites such as intestinal worms are easily seen with the naked eye. These are roundworms, flukes, and tapeworms. They usually lay their eggs on the intestinal walls. As they hatch, the young larvae feed on the food in the intestinal tract. Then they grow, reproduce, and start the cycle all over again. They sometimes dig through the digestive tract to get into the bloodstream, muscles, and other organs where they cause even more havoc. These types of parasites most often cause malnutrition and anemia because they tend to rob the body of essential nutrients it needs.
Small parasites—mostly protozoa and amoebae—are so tiny that they can only be seen with a microscope. These tiny parasites are even more dangerous to the body than the large ones. Although they usually stay in the intestines, they can migrate virtually anywhere in the body: into the bloodstream, muscles, and even vital organs such as the brain, the lungs, or the liver, where they do substantial damage.
Because parasites are everywhere, it is not difficult to become infected. People can become infested through:
In 2002, the Centers for Disease Control (CDC) announced the first documented cases of transplant patients contracting a dangerous parasitic disease from infection with T. cruzi from organs harvested from a Central American donor. The infection caused Chagas disease, causing two of the three donor recipients to die. The CDC was studying additional precautions to screen for parasitic infections like T. cruzi, explaining that even blood donors were not currently screened for the parasite. However, the agency also stressed that tissue graft surgery was still a safe procedure.
Risk factors for getting parasitic infections include:
There are more than 100 types of human parasites. The following describe some of the most common species in America.
ARTHROPODS (INSECTS). In the United States, because of high sanitary standards and a temperate climate, parasitic insects do not flourish. Common bugs such as ticks, mites, fleas, lice, and bedbugs may cause intense itching in affected areas. They are a nuisance but not a major health risk. One exception is the deer tick, which is associated with the debilitating Lyme disease. Other parasites, spread by mosquitoes, cause more serious diseases like western and eastern equine encephalitis, malaria, Dengue fever, and yellow fever.
INTESTINAL PARASITES. Some of the most common intestinal parasites include:
CNS PARASITIC INFECTIONS. Toxoplasma gondii is the most common parasite that invades the central nervous system (CNS). Humans become infected with this organism by eating raw or undercooked meat or by handling infected cat litter, which can contain eggs. Pregnant women who are infected may miscarry or deliver stillborn babies. Infected babies are born with congenital toxoplasmosis, and have symptoms that include eye inflammation, blindness, jaundice, seizures, abnormally small or large heads, and mental retardation. In people with weakened immune systems, such as AIDS patients, toxoplasmosis can affect the whole body, causing inflammation, convulsions, trembling, headache, confusion, paralysis in half of the body, or coma.
Parasitic infections are difficult to diagnose because many patients exhibit only vague symptoms or no symptoms at all. The following symptoms, however, may indicate parasitic infections:
Other symptoms of parasitic infections include anemia, blood in the stool, bloating, diarrhea, gas, loss of appetite, intestinal obstruction, nausea, vomiting, sore mouth and gums, excessive nose picking, grinding teeth at night, chronic fatigue, headaches, muscle aches and pains, shortness of breath, skin rashes, depression, and memory loss.
The following tests may be used to help doctors diagnose parasitic infections:
Infected patients who are treated with antiparasitic drugs or herbal remedies should be retested twice at the end of the treatment program; the two tests should be given one month apart.
Alternative therapies for parasitic infections reduce parasitic infections by improving nutrition and strengthening the immune system through herbal therapy and Ayurvedic medicine. Some herbal remedies are directly antiparasitic, and actually eliminate the organisms that cause disease. Patients taking allopathic antiparasitic remedies should consult their doctor before using any of these herbs. Care should be taken before giving them to children as they easily overdose.
The following dietary changes may help prevent or treat parasitic infections:
Herbal treatment should be given in combination with supportive dietary treatment and continued until the worms are completely eradicated. The following herbs are helpful in treating parasitic infestations:
Momordica charantia (bitter melon) is a very safe remedy for pinworm infection. The melon is a vegetable shaped like a cucumber with a bitter taste. It can be found in most Oriental markets. It should be sliced thinly and eaten raw with other vegetables to reduce its bitter taste. Daily consumption of one to two bitter melons per day for seven to 10 days can eliminate pinworm infection. Patients may want to repeat the regimen after several months to prevent reinfection. Chinese herbal combinations also help treat parasitic infections by supporting the gastrointestinal system, stimulating immune response, and killing parasites.
Infestations with lice, ticks, fleas, or bedbugs can be controlled by insecticides and attention to hygiene and household or environmental conatct.
Treatment for intestinal parasites usually involves antiparasitic drugs. Depending on the severity of the condition and the species involved, drug treatment may include one (or more) of the following drugs: albendazole, furazolidone, iodoquinol, mebendazole, metronidazole, niclosamide, paromomycin, pyrantel pamoate, pyrimethamine, quinacrine, sulfadiazine or thiabendazole. To prevent reinfection and transmission of disease, thorough cleaning of hands, clothes, sheets, and toys is recommended. Treatments should involve all members of the family and repeated treatments may be necessary.
Babies or AIDS patients with toxoplasmosis are often given spiramycin or sulfadiazine plus pyrimethamine. Treatment may be continued indefinitely for AIDS patients to prevent recurrence.
Though parasitic infections are difficult to diagnose, complete recovery from infestation can be effected with appropriate herbal therapy or antiparasitic drugs. Because reinfestation is common, multiple treatments may be necessary.
The following measures can help prevent parasitic infections:
Burton Goldberg Group. "Parasitic Infections." in Alternative Medicine: The Definitive Guide. Tiburon, CA: Future Medicine Publishing, Inc., 1999.
Jubelt, Burk, and James R. Miller. "Parasitic Infections." in Merritt's Textbook of Neurology, 9th ed. USA: Williams & Wilkins, 1995.
Murray, Michael T., and Joseph E. Pizzorno. "Diarrhea." in Encyclopedia of Natural Medicine, revised 2nd ed. Rocklin, CA: Prima Publishing, 1998.
Weintraub, Skye. The Parasitic Menace. Pleasant Grove, Utah: Woodland Publishing, 1998.
"CDC Detects First U.S. Cases of Parasite Disease." Immunotherapy Weekly (April 10, 2002):19.
AIDS Treatment Data Network. The NETWORK, 611 Broadway, Suite 613, New York, NY 10012. (212) 260-8868 or (800) 734-7104.
Centers for Disease Control and Prevention (CDC). International Traveler's Hotline: 404-332-4559. http://www.cdc.gov/travel/.
"Albenza Cleared by FDA for Treatment of Two Rare Infections." Doctor's Guide, Global edition. http://www.pslgroup.com/dg/96f6.htm.
"General Information: Diagnosis of Parasitic Diseases." Division of Parasitic Diseases: Public Information. http://www.cdc.gov/ncidod/dpd/public/geninfo_diagnosis_diseases.htm.
"Infectious Diseases: Parasitic Infections." Columbia University College of P & S Complete Home Medical Guide. http://cpmcnet.columbia.edu/texts/guide/hmg18_0019.html.
"Parasitic Infections." In The Merck Manual of Diagnosis and Therapy. http://www.merck.com/pubs/mmanual/section13/chapter161/161a.htm.
Teresa G. Odle