In comparison, Ancyclostoma duodenale worms are short-lived lasting for around six months. Some worms though have been recorded as living for fifteen years or more. Necator americanus can cause a prolonged infection lasting from one to five years with many worms dying in the first year or two. It takes from five to nine weeks from penetration to maturity in the intestine. In the small intestine, the larvae moult into stage four (L4) the adult worm. They then travel up the trachea and are coughed up, swallowed and end up in the small intestine. Once the larvae have entered the host they travel in the circulatory system to the lungs where they leave the venules and enter the alveoli.
A common route of passage for the larvae is the skin of barefoot walkers. americanus larvae can only infect through penetrating skin, but A. They are extremely motile and will move onto higher ground to improve their chances of finding a host. Filariform larvae can survive for up to two weeks. After feeding for seven days or so they will moult into third stage larvae (元) known as the filariform stage, which is the non-feeding, infective stage. First and second stage larvae are in the rhabditiform stage. Necator larvae can survive at higher temperatures than Ancylostoma larvae.įirst stage larvae (L1) are non-infective, and once hatched in the deposited feces, they feed on that, and then feed on soil microorganisms until they moult into second stage larvae (L2). They will die if exposed to direct sunlight or if they become dried out. Hookworm larvae need warm, moist soil, above 18 ☌, in order to hatch. The host is infected by the larvae, not by the eggs, and the usual route is through the skin. Also, the hook is much more defined in Necator americanus. americanus has a pair of cutting plates in the buccal capsule. duodenale, with males usually being 5 to 9 mm long and females about 10 mm long. Males also have a prominent copulatory bursa posteriorly. Males measure approximately 10 by 0.5 mm, and females are often longer and stouter. They have well-developed mouths with two pairs of teeth. The hook is at the front end of the body. The head is bent a little in relation to the rest of the body, forming a hook shape – hence the name. duodenale worms are pale grey or slightly pink. The two species that commonly infect humans have a similar morphology. Īt least 68 species have been described in wild mammals. Ĭattle are infected by Bunostomum phlebotomum. In Asia Ancylostoma ceylanicum is endemic among dogs and cats and infects humans. Wild cats are infected by Ancylostoma pluridentatum.ĭogs are commonly infected by Ancylostoma caninum, but may also be infected by Uncinaria stenocephala and Ancylostoma braziliense. Hookworm species that are known to infect domestic cats are Ancylostoma braziliense and Ancylostoma tubaeforme. The two most common types of hookworm that infect humans are Ancylostoma duodenale and Necator americanus.