Intestinal helminthiasis in ex-patriates returning to Britain from the tropics. A controlled study.

A retrospective study was performed of clinical features in expatriates attending the Hospital for Tropical Diseases, London, with a sole diagnosis of ascariasis (100), trichuriasis (100), hookworm (75), and strongyloidiasis (36). Results were compared with a control group of 100 ex-patriates attending the same hospital in whom no diagnosis was made and in whom stool microscopy and peripheral blood eosinophil counts were normal. Almost one half of all patients with intestinal helminthiasis were asymptomatic. Of those with symptoms specific clinical features were no different from controls with the exception of a transient itch or rash in patients with strongyloidiasis. The presence of eosinophilia was not a reliable indicator of infection. This study suggests that it may be worth while performing stool microscopy in ex-patriates returning from the tropics even if they are asymptomatic.