Answer: Ancylostoma duodenale adult worm
Disease: Hookworm infection; ankylostomiasis
The most important clinical symptom is anemia, resulting in high childhood morbidity in endemic areas. Heavy infections can result in cognitive delays, and severe growth retardation. In pregnant women, heavy infections can result in prematurity and intrauterine growth retardation.
The differential diagnosis includes hookworm infection with Necator americanus and rarely, Ancylostoma caninum, the common dog hookworm. They can be distinguished by their mouthparts: N. americanus has cutting plates instead of teeth and A. caninum has 3 pairs of teeth instead of 2.