Strongyloidiasis is an infestation of the human by the tiny 2 mm. long worm Strongyloides stercoralis that is found throughout the tropics. This worm can live freely in moist soil or its larvae may penetrate the skin of a human, enter the bloodstream, pass through the heart into the lungs, and pass from the blood into the air passages of the lung. From there it moves up into the throat, is swallowed and develops into an adult worm in the intestine. It then produces eggs, which pass out with the faeces and contaminate the soil. The eggs may also hatch into larvae in the intestine and these larvae can penetrate the bowel wall to enter the blood and reinfect the host human. There are no male and female worms, only a single asexual form.
Many patients have no or minimal symptoms, but in long standing or severe cases symptoms may include itchy buttocks and wrists, raised rashes, belly pains, nausea, diarrhoea and weight loss. Rarely in severe chronic cases the larvae may invade the liver, kidney and brain.
It is diagnosed by finding the eggs or worms in the faeces or by a specific blood test, and
then appropriate medication can be prescribed to eradicate the infestation.