Hookworm diseases are helminthic, meaning they are caused by invertebrate parasites in the human intestine. This parasite enters the body through the skin, usually the sole of the foot. It then travels around the body until it attaches itself to the small intestine, where it feeds off the blood of its host. It can lead to fatigue, impaired mental function including depression and anxiety, autoimmune conditions, iron-deficiency anaemia, vomiting and various other debilitating effects.
The parasitic roundworm Ancylostoma duodenal (old world hookworm) causes ancyclostomiasis; Necator americanus causes necatoriasis. Infection occurs mainly through vegetables, fruits, etc., which are contaminated by soil containing the larvae, deposited there from the faeces of an infected person. Nectoriasis infection can also be caused by going barefoot, because nector larvae enter the host through the skin. The dog hookworm A caninum can also infect humans.
Hookworm diseases are particularly widespread in tropical and subtropical zones, especially Latin America, Africa and Asia. According to the Centers for Disease Control (CDC), in 2018 up to 740 million people were infected with hookworm worldwide.
The United States was thought free of hookworm decades ago. But a new study by the Baylor College of Medicine reveals that hookworm is thriving once again in the southern United States.