Q: When I was in South America, I saw some children in a remote village that had worms in their stools. What is this and is it dangerous?
A: What are you describing sounds like an infection with roundworms. There are a number of species of nematodes (the scientific word for roundworms) that could be the culprit here. One likely candidate is Ascaris lumbricoides, the common roundworm, which is distributed worldwide and thought to infect more than one billion people – the most common parasitic infection in the world.
Q: What happens if I get infected with these worms? What symptoms will I have?
A: Most travelers have no symptoms, or merely vague abdominal complaints, in part because they may have only mild infections. Some with heavier infections will have epigastric pain, nausea and vomiting, and lung inflammation from new worms maturing by passing through the lungs or passage of a mature pencil-sized worm. There can be more serious symptoms such as intestinal blockage.
Q: How do I find out if I have them?
A: A diagnosis is made by looking at a stool sample under a microscope for the eggs of the worms. A mature female living in your small intestine can produce close to a quarter million eggs a day! Each type of worm has its own characteristic ova or eggs. It can also be diagnosed by identifying a mature worm that passed out your rectum. If this happens please save it in a jar. Blood tests are not useful for determining if you have Ascaris worms, though a type of white blood cell called eosinophils is often elevated with these infections.
Q: How do I get treated if I do get these worms?
A: Albendazole, mebendazole, or pyrantel pamoate will treat ascariasis. The choice of appropriate medication depends on which other worms are also present. If you have multiple types of worms and need more than one medicine to get rid of them, always make sure the first medicine you take is effective against Ascaris worms. This is because mature Ascaris worms that are irritated but not killed by drugs (or fever or starvation) have a tendency to migrate to unusual places rather than staying in your small intestine. This can result in appendicitis, pancreatitis biliary obstruction, an intestinal perforation or obstruction.
Q: How can I prevent getting worms?
A: You want to prevent the eggs that are in contaminated soil from getting into your mouth. Avoid contaminated food – raw or uncooked vegetables are common culprits. Wash your hands with soap and water before eating or preparing food. Prevent children from pica (eating dirt).
Q: Does this infection occur in the US?
A: Yes, it continues to be a minor problem in the southeastern part of the US.