It has become the most common parasitic disease of humans worldwide. Approximately two billion people (about a third of global population) are infected as of the latest estimate, and four billion at risk, surpassing even the all-time most prevalent parasitic disease, malaria.[1] The largest numbers of cases occur in impoverished rural areas of Sub-Saharan Africa, Latin America, Southeast Asia, and China.[2] Its main cause, like for many types of helminth infections, is lack of sanitation, such as the practice of open defecation and lack of hygiene such as hand washing.[3][4] It is regarded as one of the world's most important causes of intellectual and physical retardation.[5]