in immunocompetent hosts is an infrequent, clinically unimportant event, but in immunocompromised it can lead to a life-threatening illness due to hyperinfection or disseminated syndrome with large numbers of larvae affecting various organs.
stercoralis hyperinfection is considered to be an enhanced form of autoinfection
and is typically, but not always, a result of changes in the immune status .
Strongyloides infection, in contrast, can lead to autoinfection
in which rhabditiform larvae can re-penetrate the gastrointestinal mucosa or the perianal skin.
(3-5) Immunosuppression can lead to accelerated autoinfection
and a large burden of migrating larvae in the body.
These larvae are either passed in the stool or later mature into the infective filariform larva that are capable of re-invading the same host's skin or mucosa, thus restarting the parasitic cycle in a process termed autoinfection
. Such autoinfection
can lead to widespread dissemination of the infection.
Within the intestine, it may penetrate the bowel wall, leading to an autoinfection
The plausible explanation for higher infestation might be because of exceptional development pathway called autoinfection
in most of the helminths, which causes an increase in the number of adult worms inside the intestine.
Transmission typically occurs when larvae from stool-contaminated soil penetrate skin; intraintestinal autoinfection
is also possible, sometimes allowing infection to persist for decades.
Strongyloides stercoralis can cause eosinophilia years after the initial infection because the organism is capable of autoinfection
inside its host.
Moreover, the act of autoinfection
allows it to infect the same host over and over with any intermediate host.
Strongyloides stercoralis is also capable of causing autoinfection
in the host.
stercoralis has the unique feature of transmitting from the parasitic form to the infective stage within the body, rather than emerging and forming free-living stages, causing autoinfection
. (17) This may lead to latent infection for an indefinite period in an immunocompetent host, but may also cause fatal hyper-disseminated infection organ transplant recipients, cancer and other immunosuppressive condition.