199. Evaluation of Rapid Antigen Tests for the Detection of Giardia and Cryptosporidium in Human Fecal Specimens
Session: Poster Abstract Session: Antigen and Antibody Based Diagnostics
Friday, October 21, 2011
Room: Poster Hall B1
Background: Giardia and Cryptosporidium are two protozoan parasites contracted by the consumption of contaminated food/water and presents clinically as diarrhea. Available are two rapid antigen tests, ImmunoCard STAT!® Crypto/Giardia (Meridian Bioscience, Inc.) and Xpect® Giardia/Cryptosporidium (Remel, Inc.), which detect these pathogens in stool samples. We are reporting the results of a new rapid antigen test for Giardia and Cryptosporidium, TechLab’s GIARDIA/CRYPTOSPORIDIUM QUIK CHEK®, compared to the currently available test.

Methods: Stool specimens were obtained from children in an area of Bangladesh where Giardia and Cryptosporidium infections are prevalent. The sample panel included 117 both diarrheal and nondiarrheal specimens which were tested at the International Centre for Diarrheal Disease Research, Bangladesh. As a qualitative standard of measurement for the presence/absence of either or both of the antigens, individual ELISAs for Giardia and Cryptosporidium were performed using the GIARDIA II and CRYPTOSPORIDIUM II (TechLab, Inc.). PCR tests were performed on all specimens with discrepant results in addition to 10% of the other samples. PCR test results were considered as the gold standard when available otherwise the results of the ELISA tests were used. The 117 stool samples were tested by all three rapid antigen tests.

Results: For GiardiaQUIK CHEK® had a sensitivity and specificity of 94.1% and 100% respectively. This was compared to ImmunoCard STAT!® with a sensitivity and specificity of 94.1% and 94.0% respectively and Xpect® with a sensitivity and specificity of 88.2% and 97.6% respectively. For CryptosporidiumQUIK CHEK® had a sensitivity and specificity of 100% and 100% respectively. This was compared to ImmunoCard STAT!®  with a sensitivity and specificity of 90.3% and 100% respectively and Xpect®  with a sensitivity and specificity of 82.1% and 100% respectively.

Conclusion: For the detection of Giardia and Cryptosporidium, the QUIK CHEK® had a higher or equal sensitivity and specificity compared to the other two products. QUIK CHEK®’s accuracy and feasibility of use at the bedside for rapid diagnostics of Giardia and Cryptosporidium in stool samples makes it a valuable tool in patient care.

Subject Category: D. Diagnostic microbiology

Juliana Minak, MD1, Mamun Kabir, MS2, Iqbal Mahmud3, Yue Liu, BS1, Lei Liu, PhD1, Rashidul Haque, MD4 and William Petri, MD, PhD1, (1)University of Virginia, Charlottesville, VA, (2)International Centre for Diarrheal Disease Research, Dhaka , Bangladesh, (3)ICDDR,B, Dhaka , Bangladesh, (4)ICDDR,B, Dhaka, Bangladesh


J. Minak, None

M. Kabir, None

I. Mahmud, None

Y. Liu, None

L. Liu, None

R. Haque, None

W. Petri, None

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.