Ascariasis from pigs FAQs


Can people get ascariasis from a pig?

Yes. Ascaris suum is an intestinal parasite of pigs that can also infect people.

How is Ascaris suum spread to humans?

The adult Ascaris suum worm lives in the pig’s intestines and produces eggs that are passed in the pigs’ feces (manure). These eggs are deposited into the soil wherever the pig defecates. The eggs require days to weeks in the environment to become infective. Ascaris suum infection is caused by ingesting these infective eggs. This happens when

  • People don’t wash their hands thoroughly after handling pigs, cleaning pig pens, or handling pig manure; and
  • People consume fruits or vegetables grown in gardens fertilized with pig manure or in soil where pigs have previously been kept and that have not been carefully cooked, washed, or peeled.

Ascaris suum is not transmitted to people by eating pork or pork products because the worm eggs are not found in the meat.

How do I know if my pigs are infected with Ascaris suum?

Many infected pigs do not show any symptoms. Heavily infected pigs may have symptoms including the following:

  • Difficulty breathing, sometimes called “thumps”
  • Weight loss
  • Unthrifty (not strong or healthy)
  • Slow weight gain
  • Possibly passing whole worms in manure

A veterinarian can take a fecal sample from your pig(s) and look for evidence of roundworm infection. A veterinarian can also prescribe deworming medications for your pigs if they are infected.

Who is at risk for infection with Ascaris suum?

People who raise pigs or use raw pig manure as fertilizer may be at risk for infection with Ascaris suum.

How can I prevent infection with Ascaris suum?

  • Avoid contact with soil that may be contaminated with pig feces, including soil where pig manure has been used to fertilize crops.
  • Wash your hands with soap and water after handling pigs, cleaning pig pens, or handling pig manure, and always before handling food.
  • Teach children the importance of washing hands to prevent infection. Supervise children around pigs, ensuring that they do not put unwashed hands or other potentially contaminated objects in their mouths.
  • Wash, peel, or cook all raw vegetables and fruits before eating, particularly those that have been grown in soil that has been fertilized with pig manure.

Consult a veterinarian for recommendations on preventing and controlling Ascaris suum in your pigs.

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This information is not meant to be used for self-diagnosis or as a substitute for consultation with a health care provider. If you have any questions about the parasites described above or think that you may have a parasitic infection, consult a health care provider.


Page last reviewed: September 16, 2020