Ascariasis 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, 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.
Symptoms of Round worm infection
Most people infected with ascariasis have no symptoms. Moderate to heavy infestations cause various symptoms, depending on which part of your body is affected.
In the lungs
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:
Persistent cough
Shortness of breath
Wheezing
After spending six to 10 days in the lungs, the larvae travel to your throat, where you cough them up and then swallow them.
In the intestines
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:
Vague abdominal pain
Nausea and vomiting
Diarrhea or bloody stools
If you have a large number of worms in your intestine, you might have:
Severe abdominal pain
Fatigue
Vomiting
Weight loss or malnutrition
A worm in your vomit or stool
When to see a doctor
Consult your doctor if you have persistent abdominal pain, diarrhea or nausea.
Causes
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.
Life cycle of a worm
Ingestion. The microscopic ascariasis eggs can’t become infective without coming into contact with soil. People can accidentally ingest contaminated soil through hand-to-mouth contact or by eating uncooked fruits or vegetables that have been grown in contaminated soil.
Migration. Larvae hatch from the eggs in your small intestine and then penetrate the intestinal wall to travel to your lungs via your bloodstream or lymphatic system. After maturing for about a week in your lungs, the larvae break into your airway and travel up your throat, where they’re coughed up and swallowed.
Maturation. Once back in the intestines, the parasites grow into male or female worms. Female worms can be more than 15 inches (40 centimeters) long and a little less than a quarter inch (6 millimeters) in diameter. Male worms are generally smaller.
Reproduction. Male and female worms mate in the small intestine. Female worms can produce 200,000 eggs a day, which leave your body in your feces. The fertilized eggs must be in soil for at least 18 days before they become infective.
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.
Risk Factors
Age. Most people who have ascariasis are 10 years old or younger. Children in this age group may be at higher risk because they’re more likely to play in dirt.
Warm climate. In the United States, ascariasis is more common in the Southeast, but it’s more prevalent in developing countries with warm temperatures year-round.
Poor sanitation. Ascariasis is widespread in developing countries where human feces are allowed to mix with local soil.
Complications of Round worm infection
Mild cases of ascariasis usually don’t cause complications. If you have a heavy infestation, potentially dangerous complications may include:
Slowed growth. Loss of appetite and poor absorption of digested foods put children with ascariasis at risk of not getting enough nutrition, which can slow growth.
Intestinal blockage and perforation. In heavy ascariasis infestation, a mass of worms can block a portion of your intestine, causing severe abdominal cramping and vomiting. The blockage can even perforate the intestinal wall or appendix, causing internal bleeding (hemorrhage) or appendicitis.
Duct blockages. In some cases, worms may block the narrow ducts of your liver or pancreas, causing severe pain.
Tests and Diagnosis
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.
Stool tests
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.
Blood tests
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.
Imaging tests
X-rays. If you’re infested with worms, the mass of worms may be visible in an X-ray of your abdomen. In some cases, a chest X-ray can reveal the larvae in your lungs.
Ultrasound. An ultrasound may show worms in your pancreas or liver. This technology uses sound waves to create images of internal organs.
CT scans or MRIs. Both types of tests create detailed images of your internal structures, which can help your doctor detect worms that are blocking ducts in your liver or pancreas. CT scans combine X-ray images taken from many angles; MRI uses radio waves and a strong magnetic field.
Treatment and Drugs
Typically, only infections that cause symptoms need to be treated. In some cases, ascariasis will resolve on its own.
Medications
Anti-parasite medications are the first line of treatment against ascariasis. The most common are:
Albendazole (Albenza)
Ivermectin (Stromectol)
Mebendazole
These medications, taken for one to three days, kill the adult worms. Side effects include mild abdominal pain or diarrhea.