الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Copro-microscopy using both the direct smear and the formol-ether sedimentation concentration techniques diagnosed Giardia intestinalis in 164 (44.56%) of 368 fecal samples. Of copro-microscopy-positive samples, 94.69% reacted positively in the ELISA test and only 73.91% showed positive duodenal fluid microscopy. On the other hand, in 100% of copro-microscopy positive cases Giardia DNAs could be amplified in stool and duodenal fluid samples by the polymerase chain reaction using primers targeting the triose phosphate isomerase (tpi) gene. Taking the combined similar results of copro-microscopy and ELISA as the ”Gold Standard”, the estimated sensitivity and specificity of the polymerase chain reaction was 100%. A significant difference was obtained between the results of the symptomatic and asymptomatic cases using copro-microscopy, duodenal fluid microscopy, and polymerase chain reaction. The threshold of detection of Giardia intestinalis by copro-microscopy was very high (2000 cysts/g stool), comparable to the low threshold (10 cysts/g stool) of the polymerase chain reaction. As an objective test, the polymerase chain reaction eliminates the human subjective factors included in the conventional copro-microscopy and it avoids the disadvantages of the short shelf-span of the copro-antigen detection ELISA kits, since the oligonucleotide primers can be stored for a ong time. The polymerase chain reaction as a method of diagnosis is expected to contribute significantly in the diagnosis of giardiasis, and will vastly increase the understanding of its still vague epidemiology.