What Is Ascariasis?
Ascariasis is an infection of the small intestine caused
by Ascaris lumbricoides (A. lumbricoides), which is a species of
Roundworms are a type of parasitic worm. Infections caused
by roundworms are relatively common. Ascariasis is the most common roundworm
infection. About 10
percent of the developing world is infected with intestinal worms,
according to the World Health Organization (WHO). However, infections with
parasitic worms are not as common in the United States, according to the Centers for Disease Control and
Ascariasis is most common in places without modern
sanitation. It’s transmitted through unsafe food and water. The infection usually
causes no symptoms, but heavier infestations can lead to problems in the lungs
What Causes an Ascariasis Infection?
You can become infected with ascariasis after accidentally
ingesting the eggs of the A. lumbricoides roundworm. The eggs can be found in soil contaminated by human
feces or uncooked food contaminated by soil that contains roundworm eggs. Children
often become infected when they put their hands in their mouths after playing
in contaminated soil, according to WHO.
Ascariasis can also be passed directly from person-to-person.
After ingestion, the A. lumbricoides roundworm
reproduces inside your intestine. The worm goes through several stages:
- Swallowed eggs first hatch in the intestine.
- The larvae then move through your bloodstream to
- After maturing, the roundworms leave your lungs and
travel to your throat.
- You’ll either cough up or swallow the roundworms
in your throat. The worms that are swallowed will travel back to your
- Once they’re back in your intestine, the worms
will mate and lay more eggs.
- The cycle continues. Some eggs are excreted
through your feces. Other eggs hatch and return to the lungs.
Who Is at Risk for Ascariasis?
The roundworm is found worldwide, but it’s more frequently
found in tropical and subtropical regions, including Latin America and
sub-Saharan Africa. It’s also more common in areas where sanitation is poor.
factors for ascariasis include:
- lack of modern hygiene and sanitation
- use of human feces for fertilizer
- living in or visiting a warm climate
- exposure to an outdoor environment where dirt
might be ingested
Exposure to roundworms can be limited by avoiding unsafe
food and water. Keeping your immediate environment clean also helps. This
includes laundering clothing exposed to unsanitary conditions and cleaning cooking
You should make sure to take precautions if you’re visiting
a remote area. It’s important to:
- boil or filter your water
- inspect food preparation facilities
- avoid unclean common areas for bathing
Children who are 3 to 8 years old are most likely to be
What Are the Symptoms of Ascariasis?
You might not notice symptoms in the early stages of
infection. You may notice more symptoms as the roundworm infestation grows.
Roundworms in your lungs can cause:
- coughing or gagging
- vomiting roundworms
- wheezing or shortness of breath
Roundworms in your intestines can cause:
- irregular stools
- visible worms in the stool
- stomach or abdominal pain
- weight loss
Some people with a large infestation may have other
symptoms, such as fatigue and fever. A major infestation can cause extreme
discomfort. You may have all or many of the above symptoms if you don’t receive
What Are the Complications of Ascariasis?
Most cases of ascariasis are mild and don’t cause major
problems. However, heavy infestations can lead to complications. Dangerous complications
occur when worms gather in other areas of your body. They can include the
- Intestinal blockage occurs when a mass of worms
blocks your intestines causing severe pain and vomiting. Intestinal blockage is
considered a medical emergency and requires prompt treatment.
- Duct blockages occur when the worms block the
passageways to your liver or pancreas.
- Infections that lead to loss of appetite and
poor absorption can cause slowed growth and poor nutrition. This puts children
at risk of not getting enough nutrients, which can affect their growth.
Children are more likely to experience gastrointestinal
complications because their intestines are small and at a greater risk of
How Is Ascariasis Diagnosed?
People in the early stages of this condition may not have any
symptoms. Your doctor may use blood and stool samples to diagnose you.
Abdominal X-rays can also be used to diagnose ascariasis.
If your doctor diagnoses ascariasis, they may recommend
additional tests. Advanced imaging can show:
- how many worms have grown to maturity
- where major groups of worms are located
- whether worms are in the areas around your
Tests might include:
- CT scans
- MRI scans
- endoscopy, which involves placing a small camera
inside your body
It’s important for your doctor to determine how long you’ve
had this condition. That way they can evaluate your risk of complications.
How Is Ascariasis Treated?
Roundworm is usually treated with antiparasitic drugs.
Medications most commonly used for treatment include:
- albendazole (Albenza)
- ivermectin (Stromectol)
In advanced cases, other treatment may be needed. Surgery
may be used to control a larger infestation.
What Is the Long-Term Outlook for an Ascariasis Infection?
Many people recover from ascariasis with minimal treatment.
Symptoms may go away even before all of the worms are gone.
However, ascariasis can cause complications when there are
large infestations. You should see your doctor if you think you’ve been
infected with roundworms.
The best way to avoid ascariasis is through good hygiene and
by dining at reputable places. Always wash your hands with soap and water before
eating or handling food, and after using the bathroom. Teach your children to
do the same. When traveling, drink bottled water and avoid raw fruits and
vegetables unless you’re able to wash and peel them yourself.