Degree of symptoms versus copro-antigen levels in Giardia lamblia infection.

A total of 82 out-patients were examined for Giardia copro-antigens and 12 neonate stool samples as control. ELISA had a sensitivity of 100% and specificity of 91.67%. ELISA (O.D.) had neither significant correlation to Giardia cyst count, to stool consistency or presence of blood, mucus or fat in stool, nor to age but positive correlation to the severity of diarrhoea, colic, nausea, anorexia, weight loss, distension and fatigue. Giardia cyst count was higher in cases with loose stool, while ELISA (O.D.) correlated positively with symptoms except constipation and vomiting. The different in clinical outcome of giardiasis can be attributed, partially to strain differences and host resistance.