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A worm infection, ascariasis is a food-borne disease. Infections occur through eating food or ingesting drinks contaminated with the eggs of a roundworm. Uncommon in countries with good sanitation, ascariasis affects about one billion people worldwide in countries with inadequate sanitation systems. Kids are more susceptible to the disease than adults.
Ascaris lumbricoides is the scientific name for the roundworm responsible for the disease. The worm looks like an earthworm, and as an adult, is 6 to 13 inches long (about 15 to 33 cm.) An infected person can carry up to 100 worms at one time.
Contamination of food can occur if a food handler has bad personal hygiene and transfers eggs onto the food. If the food is grown using human feces as fertilizer, this can be the source of the eggs. Lack of sanitation can also mean that the general population comes into contact with human feces in public places.
Eggs picked up from a source travel through the digestive system and turn into larvae. The worm in this larval stage infects the body through the intestinal wall. Then, they use the blood or lymph networks to move to the lungs, where they travel to the throat.
The infected person swallows the larva back into the stomach and into the small intestine. The worms reach adult stage only then, after about two months, and can breed, producing eggs that leave the body through feces. The cycle begins again when another person picks up the eggs and becomes infected. Each worm can live up to two years in one body.
Often, ascariasis does not cause symptoms, especially if the carrier has a small number of worms. A sufferer may notice worms in feces or in vomit. In the lung stage of the infection, ascariasis can cause coughing or wheezing, and the person may even cough up worms or expel them through the nose.
In the case of a severe infection, the worms can affect the normal movements of the bowel by blocking the small intestine. This can show itself through stomach pain, problems sleeping, and vomiting. Death is a possibility with a severe case of ascariasis.
Possible treatments for the worm infection include the drugs albendazole and mebendazole. Intestinal blockages can be cleared of worms through endoscopic procedures or surgical operations. Without treatment, an ascariasis sufferer may find his or her symptoms resolve, but the worms may still be present in the body.