- Ascaris: common, lung passage, sometimes intestinal or biliary obstruction
- Trichuris: common, symptoms only in severe infection (diarrhoea, anal prolapse)
- Enterobius: common, anal itch, exogenous auto-infection
- Hookworms: common, lung passage, anaemia if worms are numerous
- Strongyloides: common, chronic, larva currens, lung passage, endogenous re-infection, fatal hyperinfection
- Capillaria philippinensis: rare, diarrhoea, endogenous re-infection, sometimes fatal
The first five species are currently aggregated under the term “soil-transmitted helminthiasis” (STH). More than a billion people are infected with a least one species.