Ascariasis (as-kuh-RIE-uh-sis) is a type of roundworm infection. These worms are parasites that use your body as a host to mature from larvae or eggs to adult worms. Adult worms, which reproduce, can be more than a foot (30 centimeters) long.
One of the most common worm infections in people worldwide, ascariasis is uncommon in the United States. Most infected people have mild cases with no symptoms. But heavy infestation can lead to serious symptoms and complications.
Ascariasis occurs most often in children in tropical and subtropical regions of the world — especially in areas with poor sanitation and hygiene.
Most people infected with ascariasis have no symptoms. Moderate to heavy infestations cause various symptoms, depending on which part of your body is affected.
After you ingest the microscopic ascariasis eggs, they hatch in your small intestine and the larvae migrate through your bloodstream or lymphatic system into your lungs. At this stage, you may experience signs and symptoms similar to asthma or pneumonia, including:
After spending six to 10 days in the lungs, the larvae travel to your throat, where you cough them up and then swallow them.
The larvae mature into adult worms in your small intestine, and the adult worms typically live in the intestines until they die. In mild or moderate ascariasis, the intestinal infestation can cause:
If you have a large number of worms in your intestine, you might have:
Consult your doctor if you have persistent abdominal pain, diarrhea or nausea.
Ascariasis isn't spread directly from person to person. Instead, a person has to come into contact with soil mixed with human feces that contain ascariasis eggs or infected water. In many developing countries, human feces are used for fertilizer, or poor sanitary facilities allow human waste to mix with soil in yards, ditches and fields.
Small children often play in dirt, and infection can occur if they put their dirty fingers in their mouths. Unwashed fruits or vegetables grown in contaminated soil also can transmit the ascariasis eggs.
The whole process — from egg ingestion to egg deposits — takes about two or three months. Ascariasis worms can live inside you for a year or two.
In heavy infestations, it's possible to find worms after you cough or vomit, and the worms can come out of other body openings, such as your mouth or nostrils. If this happens to you, take the worm to your doctor to identify it and prescribe the proper treatment.
Mature female ascariasis worms in your intestine begin laying eggs. These eggs travel through your digestive system and eventually can be found in your stool.
To diagnose ascariasis, your doctor will examine your stool for the microscopic eggs and larvae. But eggs won't appear in stool until at least 40 days after you're infected. And if you're infected with only male worms, you won't have eggs.
Your blood can be tested for the presence of an increased number of a certain type of white blood cell, called eosinophils. Ascariasis can elevate your eosinophils, but so can other types of health problems.
Mild cases of ascariasis usually don't cause complications. If you have a heavy infestation, potentially dangerous complications may include:
The best defense against ascariasis is good hygiene and common sense. Follow these tips to avoid infection:
Risk factors for ascariasis include: