Humans can be affected by various types of worms, including threadworms (pinworms), tapeworms, roundworms, and whipworms. These parasites primarily inhabit the intestines and can spread through contact with contaminated food, surfaces, or direct human contact. Worm eggs may be present in raw meat and on unwashed vegetables, and children are particularly at risk of infection from handling contaminated toys.
The most prevalent worm infection is caused by threadworms, also known as pinworms. These small, white worms measure about one centimetre in length and lay their eggs around the anus, causing itching in the affected area. Scratching the itchy area can lead to the spread of eggs to other people and surfaces, making it easy for the infection to recur, especially in children.