see also:

• parasites
• antihelminths
• the febrile returned traveller

• a human parasitic disease caused by the nematode (roundworm) Strongyloides stercoralis, or sometimes S. fülleborni.
• thought to affect 30–100 million people worldwide, mainly in tropical and subtropical countries.
• it is a helminth that is endemic to tropical and subtropical regions of the world, across Central and South America, sub-Saharan Africa, northern Australia and Asia
• does not require an intermediate host but does require maturation in soil
• infection is via either:
  • filariform larva from soil penetrating intact skin, or,
  • auto-infection by rhabditiform larvae in the colon penetrating bowel wall or peri-anal skin
• risk for infection is particularly in those who walk barefoot in endemic faecally contaminated soil such as rural areas with poor sanitation

• often asymptomatic
• usually associated with eosinophilia

• Loffler's syndrome (acute onset eosinophilic pneumonitis) can also be caused by Ascaris lumbricoides, and the hookworms Ancylostoma duodenale and Necator americanus.

• may become asymptomatic
• abdominal pain, diarrhoea, eosinophilia, urticarial rashes (esp. waist and buttocks)

• there may be respiratory, skin and digestive symptoms

• may involve many organ systems including CNS
• may occur many decades after initial infection and develops when immunity falls eg. high dose corticosteroids, organ transplant drugs, malnutrition, advanced tuberculosis (TB), etc.
• high mortality rate and may lead to disseminated infection

• The drug of choice for the treatment of uncomplicated strongyloidiasis is ivermectin.
• ivermectin does not kill the strongyloides larvae only the adult worms therefore repeat dosaging may be necessary to properly eradicate the infection.
• There is an auto-infective cycle of roughly two weeks in which ivermectin should be re-administered however additional dosaging may still be necessary as it will not kill strongyloides in the blood or larvae deep within the bowels or diverticuli.