Hookworms are soil-transmitted nematode parasites that can reside for many years in the small intestine of their human hosts, where they suck blood and can cause iron deficiency anaemia (IDA) in individuals who harbour moderate and high numbers of adult worms, which is known as hookworm disease
Hookworms are nematodes belonging to the family Ancylostomatidae, a part of the superfamily Strongyloidea. The two major genera that affect humans, Necator and Ancylostoma, are characterized by the presence of either teeth or cutting plates that line the adult parasite buccal capsule
Necatur americanus (predominant human hookworm globally)
Ancylostoma duodenale (focally endemic in Mediterranean region, in northern India & China and in North Africa)
Ancyclostoma braziliense “Dog hookworm” (parasite adapted for dogs and hence cannot enter human circulation and wander in skin causing creeping eruptions)
Briefly, humans become infected with hookworms when third-stage infective larvae (L3) penetrate the skin and then migrate into subcutaneous venules and lymphatics before traveling via the afferent circulation to the pulmonary capillary bed. From there, L3 enter the respiratory tree through the alveolae and ascend the bronchioles and the bronchi, pass over the epiglottis, and enter the gastrointestinal tract. In the small intestine, L3 molt twice to become adult male and female hookworms where they can live for five years or more. The adult worms, approximately one centimeter in length, attach to the mucosa and submucosa, rupture capillaries and arterioles, and then feed on host blood and mucosal tissues. The hookworms mate and female worms then produce thousands of eggs that exit the body in the feces. The eggs hatch in soil with adequate moisture and high temperature and then molt twice into L3 that seek higher ground to come into contact with human skin.
Although initial skin invasion might go unnoticed, it can result in a local pruritic, erythematous rash, referred to as ‘ground itch’.
Local pruritic, erythematous rash
Typically appears on hands and feet (main sites of L3 percutaneous entry; via hair follicles, which are the path of least resistance).
Intestinal blood loss
Main clinical manifestation of human hookworm infection. Blood loss can be as high as 9·0 mL/day in heavy infections, with hookworm burdens of 40–160 worms sufficient to cause anemia
Iron deficiency anemia (IDA): Occurs on blood host with poor nutritional background
Systemic eosinophilia: Often asymptomatic, although flatulence is common for the first 12 weeks and gastrointestinal disturbance is sometimes reported within the first 3–15 weeks
A day of fun at the beach turned into a nightmare for one teen. Michael Dumas, 17, was buried in the sand by his buddies. He didn’t know it at the time, but lurking in the sand were tiny parasites known as hookworms. They bit into Michael’s foot and crawled beneath his skin. As the hookworms made a home there, Michael developed painful sores that became infected. The hookworms most likely came from an infected dog.
As hookworms are parasites of the digestive system, the diagnostic examinations use samples of fresh, fixed or frozen faeces, in which hookworm eggs (ova), larvae and whole or parts of the parasites can be detected.
Water, Sanitation and Hygiene (WASH) programme
Diverse and include a range of improvements in water conditions (such as quality, quantity and access), sanitation (such as improved latrines and sewer maintenance) and hygiene (for example, adopting good personal hygiene habits, such as hand washing before eating and after defaecation, wearing shoes and safely storing water)
Benzimidazole anthelmintic therapies:
These drugs act by inhibiting microtubule polymerization in invertebrates, therefore killing adult worms.