Comparison of Nine Commercially Available Enzyme-Linked Immunosorbent Assays for Detection of Giardia lamblia in Fecal Specimens

Abstract

Overall performance, including ease of use, total hands-on time, incubation and processing times, sensitivity, and specificity, of each of nine enzyme-linked immunosorbent assays (ELISAs) were compared by using 222 individual fecal samples submitted for the detection ofGiardia lamblia. The assays evaluated were manufactured by Alexon, Inc., Cambridge Biotech Corp., Meridian, Inc., and Trend Scientific, Inc. All assays used polyclonal antibodies except the “new and improved” Microplate (direct and diluted methods) by Alexon, which is a monoclonal antibody assay. Seventy specimens were positive for G. lamblia by ELISA, ova and parasite test, and/or direct fluorescent-antibody assay. One hundred fifty two were negative by all three methods. Sensitivities and specificities ranged from 88.6 to 100% and 99.3 to 100%, respectively. The total hands-on time needed to run one specimen ranged from 1 min to 2 min 17 s per specimen. All except one commercially available ELISA were found to be rapid, sensitive, and specific for the detection of G. lamblia in fecal specimens.

Evaluation of seven commercial antigen detection tests for Giardia and Cryptosporidium in stool samples

“…The Cryptosporidium-Strip had a sensitivity of only 75.0%. Sensitivity rates reported previously for various commercially available immunochromatographic and EIAs detecting Giardia and ⁄ or Cryptosporidium copro-antigen range from 63% to 100% [4,7,8,[17][18][19][20][21]. Since different studies evaluating identical assays report diverse sensitivity values, it seems that the test performances are also influenced by the study methodology and data analysis.…”

Traveler's Diarrhea Due to Intestinal Protozoa

“…Giardia species can be visualized in trichrome iodine stains of fecal smears or by use of direct immunofluorescence. However, detection by means of ELISA is becoming the preferred diagnostic tool [5]. The antiparasitic agent of choice remains metronidazole.…”

Comparison of Direct Immunofluorescence, Immunoassays, and Fecal Flotation for Detection of Cryptosporidium spp. and Giardia spp. in Naturally Exposed Cats in 4 Northern California Animal Shelters

“…16,17 have raised awareness of the human health risks and motivated the development of new diagnostic tests for people. Although extensively validated in people, [18][19][20][21] few studies document the performance characteristics (eg, sensitivity, specificity, ease of use) of these tests in cats. 22 A recent study 22 examined several commercially available immunoassays for the diagnosis of Cryptosporidium spp.…”