Evaluation of an immunochromatographic dip-strip test for the detection of Cryptosporidium oocysts in stool specimens.

The study presented here examined the efficacy of a commercially available qualitative immunochromatographic assay for detecting Cryptosporidium oocysts in stool samples. A total of 75 samples were tested, including 50 positive for Cryptosporidium spp. by acid-fast stain, 20 positive for other parasites ( Blastocystis hominis, Endolimax nana, Entamoeba coli, Giardia lamblia, Ascaris lumbricoides, Strongyloides stercoralis and Trichuris trichiura), and five negative samples. The observed sensitivity was 98%, while specificity was 100%; the detection threshold was near 1000 oocysts/ml. Correctly diagnosed positive samples included Cryptosporidium parvum genotypes 1 and 2, whereas the single false-negative sample corresponded to a Cryptosporidium meleagridis infection.