Necator americanus

Name

Latin: necator = killer; americanus = American origin.

Geographic Distributions/Epidemiology

Humid warm regions in America, Central Africa, and South and East Asia between 30° South and 45° North. About 400–450 million people are infected and several more constantly endangered.

Morphology/Life Cycle

The adult male and female of this hook worm species reach both a length of about 1 cm and are morphologically different from Ancylostoma duodenale (=Old World hookworm) as can be seen in Table 1, while the eggs of both species cannot become clearly differentiated from each other (Figs. 1, 2, 3, and 4). The adult worms live in the jejunum region of the human intestine, being constantly attached by their typical cutting plates at the intestinal wall (Fig. 1; 1b). They permanently suck blood and ingest even more than they need for feeding. Apparently, they use the oxygen included in the blood cells for their own purpose. This nondigested blood leads to the fact that an infection with...