Necator americanus

Necator americanus is a species of hookworm responsible for about 90 percent of human hookworm infections worldwide. These parasitic worms live in the small intestine and are a cause of hookworm disease, which can be associated with secondary anemia.1

Life Cycle and Transmission

The adult N. americanus worm attaches to the lining of the small intestine, where females lay thousands of eggs daily. These eggs are passed in feces, and if they reach suitable soil, they hatch into infective larvae. These larvae can penetrate human skin, typically on the feet, through sweat glands and hair follicles. The larvae then travel through the lymph and blood vessels to the lungs, eventually reaching the mouth, where they are swallowed and mature in the small intestine, starting a new reproductive cycle.1

Symptoms

Symptoms of hookworm disease can include an itchy skin irritation where the larvae penetrate, coughing, and fever as the larvae pass through the lungs. In the intestine, the worms feed on blood, leading to anemia in persistent infestations. Heavy infections can cause pallor, fluid retention, digestive issues, stunted growth, fatigue, and apathy.1

Prevention and Treatment

Hookworm infestation is common in tropical and subtropical regions due to factors like moisture, warmth, loose soil, and lack of footwear. Treatment often involves medication such as tetrachlorethylene for N. americanus, along with iron supplements and a protein-rich diet. Prevention focuses on sanitary disposal of human excreta.1