Table 4.

Diagnostic tests' results on 250 random stool samples.

Test result	Microscopy	The algorithma	The reference PCRsb
Cryptosporidium-positive	13	24	26
Giardia-positive	33	42	42
Cryptoc/Giardia-negative	204	184	182
Total	250	250	250

^aThe algorithm picked 20 positive samples more than the staining methods adopted at the Microbiology Laboratory at King Faisal Hospital. These samples were also positive for protozoan DNA by the matching reference PCR assay. ^bTwo Cryptosporidium DNA positive samples were diagnosed by PCR and missed by the algorithm. ^c Crypto stands for Cryptosporidium.