The
hookworm is a
parasite that lives in the
small intestine of its host, which may be a
mammal such as a
dog,
cat, or
human. Two species of hookworms commonly infect humans,
Ancylostoma duodenale and
Necator americanus. The distribution of each species significantly overlaps that of the other.
Necator americanus predominates in The Americas and
Australia, while only
A. duodenale is found in the
Middle East,
North Africa and southern
Europe. Hookworms are thought to infect 800 million people worldwide. The
A. braziliense species infects cats, while
A. caninum infects dogs.
These worms are much smaller than the large
roundworm,
Ascaris lumbricoides, and the complications of tissue migration and mechanical obstruction so frequently observed with roundworm infestation are less frequent in hookworm infestation. The most significant risk of hookworm infection is
anemia secondary to loss of
iron (and
protein) into the gut.
Hookworms are leading causes of maternal and child morbidity in the developing countries of the
tropics and
subtropics. In susceptible children hookworms cause intellectual, cognitive and growth retardation; as well as intrauterine growth retardation,
prematurity and low birth weight among newborns born to infected mothers. Hookworm infection is rarely fatal, but anemia can be significant in the heavily infected individual.
Hookworm life cycle
life cycle]]
See the image for the
biological life cycle of the hookworm.
The hookworm
larva lives in infected
soil. The larva penetrates the
skin on contact, e.g. when walking
barefoot, enters the
bloodstream and is transported to the
lungs. From the lungs and
bronchi it transfers to the
stomach and intestine by
coughing up and swallowing
phlegm. The larva attaches to the intestine wall and developes into an adult hookworm. The adult releases
eggs that leave the human body with the
feces. The eggs hatch in soil and eventually develop into larva.
To prevent hookworm infection:
See also
External link
Category:Roundworms
Category:Parasitology