Roundworms are worms that can infest the human digestive tract, specifically the small intestine. Their proper name is ascaris lumbricoides, so a roundworm infection is also known as ascariasis.
Roundworms are parasites
Roundworms are parasites, which means that they exploit the human body to stay alive, feed and reproduce.
A roundworm infection can develop when you swallow ascaris eggs in contaminated food, soil or water. After a while, the eggs mature into adult worms which, in turn, produce eggs. The eggs are released from your body when you empty your bowels, and can infect other humans.
How common are roundworm infections?
Roundworm infection is one of the most common health conditions in the world. It's estimated that one billion people currently have a roundworm infection.
The condition is widespread in Africa, China, South East Asia, and Central and South America. It's very rare in the UK, so it's thought that most cases that are reported in the UK were contracted abroad.
An average of 80 cases of roundworm are reported every year in England, Wales and Northern Ireland.
In most people, roundworms will cause no symptoms, or only symptoms of mild indigestion. But if the number of worms increases, or the worms move from the small intestine to other parts of the body, they can cause more serious, and sometimes fatal, complications.
Estimates of the numbers of deaths caused by roundworm vary significantly, possibly because it is hard to get accurate clinical data from the poorer parts of the world. Figures range from 10,000 to 100,000 deaths a year, most of which are children.
Prognosis
Roundworms present a serious health problem in parts of the developing world. Many poorer people don't have access to healthcare, so a roundworm infection can become serious. Malnutrition also makes the symptoms of roundworm worse and increases the risk of complications.
In the UK, cases of roundworm can be treated easily, and should not present a serious health problem.
