Chronic giardiasis: studies on drug sensitivity, toxin production, and host immune response.

Abstract

(a) The chronicity of our patient's infection was not due to the organism having unique properties of drug resistance. (b) Combined quinacrine and metronidazole, which cured our patient's chronic giardiasis, should be tried in patients in whom infection persists after single drug therapy. (c) The diarrhea in our patient was probably caused by a mechanism other than Giardia lamblia-induced secretion by currently recognized enterotoxins. (d) Reduced cellular cytotoxicity for Giardia lamblia may have contributed to the persistence of our patient's infection and should be suspected in other patients with chronic giardiasis.