Ascariasis is an intestinal infection caused by a parasitic
roundworm. While it is the most common human infection caused by
worms in the world, ascariasis is not common in the United States.
It occurs in varying prevalence worldwide, with far greater
frequency in areas with poor sanitation or crowded living
conditions.
Signs and Symptoms
Although no symptoms may occur, the greater the number of worms
involved in the infestation, the more severe a child's symptoms
are likely to be. Kids are more likely than adults to develop
gastrointestinal symptoms because they have smaller intestines and
are at greater risk of developing intestinal obstruction.
Symptoms seen with mild infestation include:
- worms in stool
- coughing up worms
- loss of appetite
-
fever
- wheezing
More severe infestations can result in more serious signs and
symptoms, including:
-
vomiting
- shortness of breath
- abdominal distention (swelling of the abdomen)
- severe stomach or abdominal pain
- intestinal blockage
- biliary tract blockage (includes the liver and
gallbladder)
Description
Ascariasis occurs when worm eggs of the parasite
Ascaris lumbricoides
commonly found in soil and human feces are ingested. The eggs can
be transmitted from contaminated food, drink, or soil. The
roundworms range in size from 5.9 to 9.8 inches for adult males and
9.8 to 13.8 inches for adult females. The worms can grow to be as
thick as a pencil and can live for 1 to 2 years.
Ascariasis is frequently found in developing countries where
sanitary conditions are poor or in areas where human feces are used
as fertilizer. When the eggs are swallowed and passed into the
intestine, they hatch into larvae. The larvae then begin to move
through the body.
Once they get through the intestinal wall, the larvae travel
from the liver to the lungs through the bloodstream. During this
stage, pulmonary symptoms such as coughing (even coughing up worms)
may occur. In the lungs, the larvae climb up through the bronchial
tubes to the throat, where they are swallowed. The larvae then
return to the small intestine where they grow, mature, mate, and
lay eggs. The worms reach maturity about 2 months after an egg is
ingested from the soil.
Adult worms live and remain in the small intestine. A female
worm can produce up to 240,000 eggs in a day, which are then
discharged into the feces and incubate in the soil for weeks.
Children are particularly susceptible to ascariasis because they
tend to put things in their mouths, including dirt, and they often
have poorer hygiene habits than adults.
Ascariasis is common in warmer or tropical climates,
particularly in developing nations, where it can affect large
segments of the population. Ascariasis is rare in the United
States, due to strict sanitation rules and regulations.
Contagiousness
Ascariasis is not spread directly from one person to another. To
become infected, an individual has to consume the worm's
eggs.
Prevention
The most important measure of protection against ascariasis is
the safe and sanitary disposal of human waste, which can transmit
eggs. Areas of the world that use human feces as fertilizer must
thoroughly cook all foods or clean them with a proper iodine
solution (particularly fruits and vegetables).
Children who are adopted from developing nations are frequently
screened for worms as a precautionary measure. Kids who live in
underdeveloped areas of the world may be prescribed a preventive
deworming medication.
These practices are recommended for all children:
- Try as much as possible to keep kids from putting things in
their mouths.
- Teach kids to
wash hands
thoroughly and frequently, especially after using the bathroom
and before eating.
Professional Treatment
The doctor will usually prescribe antiparasitic medication to be
taken orally to kill the intestinal roundworms. Sometimes the stool
will be re-examined about 3 weeks after treatment to check for eggs
and worms. Symptoms usually disappear within 1 week of starting
treatment.
Very rarely, surgical removal of the worms may be necessary
(particularly in cases of intestinal or liver-related obstruction,
or abdominal infection). A child who has ascariasis should be
evaluated for other intestinal parasites, such as pinworm.
Home Treatment
If your child has ascariasis, the medication prescribed should
be administered accordingly. To prevent reinfection:
- Ensure that your child washes his or her hands properly,
particularly after using the bathroom and before eating.
- Have your pets checked for worms regularly.
- Keep your child's fingernails short and clean.
- Sterilize any contaminated clothing, pajamas, and
bedding.
- Evaluate the source of the infection. Additional sanitation
measures in or around your home may be necessary.
When to Call the Doctor
If your child has any of the symptoms of ascariasis, contact
your doctor right away.
Stool
samples will be sent to a laboratory to check for eggs and worms
and confirm the diagnosis.
Call the doctor if symptoms do not improve with treatment or if
new symptoms occur.
Reviewed by:
Joel Klein, MD
Date reviewed: October 2008
Note: All information is for educational purposes only. For specific medical advice,
diagnoses, and treatment, consult your doctor.
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