Parasite Cleanse

Ascaris lumbricoides and Ascaris suum
(intestinal roundworms of humans and pigs)

Ascaris lumbricoides is one of the largest and most common parasites found in humans.  The adult females of this species can measure up to 18 inches long (males are generally shorter), and it is estimated that 25% of the world's population is infected with this nematode.  The adult worms live in the small intestine and eggs are passed in the feces.  A single female can produce up to 200,000 eggs each day!  About two weeks after passage in the feces the eggs contain an infective larval or juvenile stage, and humans are infected when they ingest such infective eggs.  The eggs hatch in the small intestine, the juvenile penetrates the small intestine and enters the circulatory system, and eventually the juvenile worm enters the lungs.  In the lungs the juvenile worm leaves the circulatory system and enters the air passages of the lungs.  The juvenile worm then migrates up the air passages into the pharynx where it is swallowed, and once in the small intestine the juvenile grows into an adult worm.  Why Ascaris undergoes such a migration through the body to only end up where it started is unknown.  Such a migration is not unique to Ascaris, as its close relatives undergo a similar migration in the bodies of their hosts (view diagram of the life cycle below).

Ascaris infections in humans can cause significant pathology.  The migration of the larvae through the lungs causes the blood vessels of the lungs to hemorrhage, and there is an inflammatory response accompanied by edema.  The resulting accumulation of fluids in the lungs results in "ascaris pneumonia," and this can be fatal.  The large size of the adult worms also presents problems, especially if the worms physically block the gastrointestinal tract.  Ascaris is notorious for its reputation to migrate within the small intestine, and when a large worm begins to migrate there is not much that can stop it.  Instances have been reported in which Ascaris have migrated into and blocked the bile or pancreatic duct or in which the worms have penetrated the small intestine resulting in acute (and fatal) peritonitis.  Ascaris seems to be especially sensitive to anesthetics, and numerous cases have been documented where patients in surgical recovery rooms have had worms migrate from the small intestine, through the stomach, and out the patient's nose or mouth.

Ascaris suum is found in pigs. Its life cycle is identical to that of A. lumbricoides. If a human ingests eggs of A. suum the larvae will migrate to the lungs and die.  This can cause a particularly serious form of "ascaris pneumonia."  Adult worms of this species do not develop in the human's intestine.  (Some parasitologists believe that there is but one species of Ascaris that infects both pigs and humans, but any commentary on this issue is beyond the scope of this web site.)

Infections of Ascaris are diagnosed by finding characteristic eggs in the feces of the infected host.

A large mass of Ascaris lumbricoides that was passed from the intestinal tract.  The ruler at the bottom of the image is 4 cm (about 1.5 inches) in length.  

 

An en face view of Ascaris.  Note the presence of three large lips, a characteristic of all ascarids.   (Original image from Oklahoma State University, College of Veterinary Medicine.)

 

A scanning electron micrograph of the anterior end of Ascaris showing the three prominent "lips."  (Original image from "Wormland".)

 

Ascaris lumbricoides, fertilized egg.  Note that the egg is covered with a thick shell that appears lumpy (bumpy) or mammillated; approximate size = 65 µm in length.

 

Another example of a fertilized Ascaris lumbricoides egg.  (Original image from: Atlas of Medical Parasitology.)

 

An example of an unfertilized A. lumbricoides egg.  (Original image from: Atlas of Medical Parasitology.)

 

A "decorticated," fertilized, Ascaris lumbricoides.  (Original image from: Atlas of Medical Parasitology.)

 

Eggs of Ascaris suum.  A. suum is a common parasite of pigs.  The eggs are virtually indistinguishable from those of A. lumbricoides.  (Original image from Oklahoma State University, College of Veterinary Medicine.)

 

A female Ascaris lumbricoides.  Females of this species can measure over 16 inches long.  This specimen was passed by a young girl in Florida.  (Original image from DPDx [Identification and Diagnosis of Parasites of Public Health Concern].)

 

Female and male Ascaris lumbricoides; the female measures approximately 16 inches (40 cm) in length.

 

 

Adult Ascaris lumbricoides worms (1) live in the lumen of the small intestine. A female may produce 200,000 eggs each day, which are passed with the feces (2) of the host. Ingested unfertilized eggs are not infective, but fertile eggs begin to develop and become infective after 18 days to several weeks (3), depending on environmental conditions (an optimal environment being moist, warm, shaded soil). After infective eggs are swallowed (4), the larvae hatch (5), invade the intestinal mucosa, and are carried via first the portal and then the systemic circulation to the lungs (6). The larvae mature further in the lungs for 10 to 14 days, then penetrate the alveolar walls, ascend the bronchial tree to the throat, and are swallowed (7). Upon reaching the small intestine, they develop into adult worms (1). Between two and three months are required from ingestion of infective eggs to oviposition (egg-laying) by the adult female. Adult worms can live one to two years.

 

These wonderful images are provided to you by:

www.biosci.ohio-state.edu

They an extensive library of information on over 300 types of parasites!

 

 18 day parasite cleanse by Dr. Hulda Clark.