Immunofluorescent detection of both Giardia lamblia and Cryptosporidium parvum using anti-Cryptosporidium oocyst antibodies.

Giardia lamblia and Cryptosporidium parvum are two protozoal parasites proved to have a major role in gastroenteritis in humans. Both are documented to coexist in many waterborne parasitic transmission, as well as in outbreaks. In the present work, a polyspecific anti-Cryptosporidium oocyst antibodies were used for simultaneous detection of both parasites in human stool. Known positive formalinized human stool specimens of Giardia sp. (n = 10), Cryptosporidium sp. (n = 7), mixed infection (n = 3), and negative specimens (n = 20), were tested using direct fluorescent technique against the developed antibodies. All positive stool samples for Cryptosporidium and 9 out of 10 Giardia samples, or each alone showed fluorescence with variable intensities, while no negative sample harboured other parasites had fluorescence. This newly used polyspecific antibodies offer the advantages of screening large number of patients, particularly in outbreaks. Additionally, it represents a cheaper alternative for the most sophisticated and costly immunoassay kits using the monoclonal antibodies, with more or less the same diagnostic potentials.