The worm is
Strongyloides stercoralis, a “threadworm” nematode that causes
strongyloidiasis.
S. stercoralis has a peculiar life cycle that involves unfortunate humans coughing up, then swallowing larva after they invade the blood stream. From there, adult
S. stercoralis discreetly inhabits mucus tunnels in the small intestines, sometimes for a person’s whole life.
It often causes no symptoms. But when it does, symptoms are often mild and vague, such as cramps, diarrhea, weight loss, or a rash.
That all changes if the infected person suffers a blow to their health that compromises their immune system or if they take immunosuppressive drugs, such as some steroid drugs. In those cases, the worm can abruptly cause a life-threatening “hyperinfection” and spread throughout the body. In a hyperinfection, the worm’s reproduction shifts to ludicrous speed, resulting in an overwhelming number of worms. These can disseminate, spreading far beyond the intestines, causing massive full body infection. A disseminated hyperinfection can cause death
in up to 87 percent of cases.
