Pinworms are small, white roundworms that sometimes live in the colon and rectum of humans. Pinworm infections are extremely common, occurring worldwide, it is estimated by the CDC that more than 40 million cases occur each year. According to the International Journal of Gastroenterology and Hepatology, 74.3% of individuals are infected with the parasite in the developing community of south India where water sources are scarce. In another research article, 42.06% of the 781 individuals tested were positive for the parasite in the developing district of north Thailand. While an infected person sleeps, the pinworm deposits their eggs causing itching around the anus. When someone scratches their perianal area, eggs may become lodged underneath their fingernails, spreading to anything he or she touches. Due to the great risk for infection, good hygiene is important to prevent and control the spread of pinworms. Effective ways to control infections are: appropriate handwashing, daily morning baths, and trimming and scrubbing the fingernails.