Comparative Evaluation of Three Methods (Microscopic Examination, Direct Fluorescent Antibody Assay, and Immunochromatographic Method) for the Diagnosis of Giardia intestinalis From Stool Specimens

Aim. To determine the frequency of detection of conjunctivalC. trachomatis(CT),M. hominis(MH), andU. urealyticum(UU) infections in young adults with dry eye disease (DED), since these infections may potentially produce the chronic subclinical inflammation characteristic of DED.Materials and Methods. The study included subjects of 25–45 years of age, divided into the DED (n=114) and nondry eye control (n=98) groups, with the diagnosis based on self-reported complaints, biomicroscopy, the Schirmer I test, and break-up time. All patients had conjunctival scrapings taken to detect CT, MH, and UU with direct fluorescent-antibody assay kits.Results. At least one of the three microorganisms was found in 87.7% of the DED patients versus 8.2% of the controls. Of all the DED patients, 63.2%, 50.8%, and 42.1% were found to be infected with CT, MH, and UU, respectively. Multiple pathogens were identified in 65% of the DED patients found to be infected. CT infection was detected in 6.1% of the controls.Conclusion.C. trachomatis,M. hominis, andU. urealyticumwere detected with high frequency in the conjunctiva of young adults with DED and may be an important risk factor for DED in them.

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Performance of Three Enzyme Immunoassays and Two Direct Fluorescence Assays for Detection of Giardia lamblia in Stool Specimens Preserved in ECOFIX

Journal of Clinical Microbiology ◽

10.1128/jcm.38.7.2781-2783.2000 ◽

2000 ◽

Vol 38 (7) ◽

pp. 2781-2783 ◽

Cited By ~ 10

Author(s):

Daniel P. Fedorko ◽

Esther C. Williams ◽

Nancy A. Nelson ◽

Leslie B. Calhoun ◽

Sizhuang S. Yan

Keyword(s):

Giardia Lamblia ◽

Fluorescent Antibody ◽

The Other ◽

Specific Enzyme ◽

Enzyme Immunoassays ◽

Direct Fluorescent Antibody ◽

Direct Fluorescence ◽

Stool Specimens ◽

The Difference ◽

Formalin Fixed

ECOFIX is a single-vial stool preservative that is both formalin- and mercury-free. We evaluated the abilities of three commercialGiardia lamblia-specific enzyme immunoassays (EIAs) (ProSpecT Giardia Microplate Assay [Alexon-Trend Inc.], Giardia Test [Techlab], and Premier Giardia lamblia [Meridian Diagnostics, Inc.]) and two commercial direct fluorescent-antibody (FA) assays for G. lamblia(Crypto/Giardia IF Test [Techlab] and Merifluor Cryptosporidium/Giardia [Meridian Diagnostics, Inc.]) to detectG. lamblia in 34 G. lamblia-positive and 44G. lamblia-negative stool specimens (determined by traditional examination for ova and parasites) preserved in ECOFIX compared to their abilities to detect G. lamblia in the same specimens preserved in formalin as the “gold standard” for each assay. Of the 34 formalin-fixed positive specimens, the number detected by each assay was as follows:, Alexon EIA, 34; Meridian EIA, 27; Techlab EIA, 29; Meridian FA assay, 31; and Techlab FA assay, 28. Both FA tests and the Alexon EIA performed well with ECOFIX, but the other two EIAs detected fewer positive specimens (the difference was statistically significant with the Techlab EIA) when ECOFIX was the preservative. Use of G. lamblia cyst antigen from cultured organisms preserved in formalin and ECOFIX demonstrated that the Alexon EIA could detect smaller amounts of antigen in ECOFIX than the other two EIAs could and suggested that cyst antigen is more stable in formalin. We recommend that laboratories use an FA assay or the Alexon EIA if they plan to use ECOFIX as their stool preservative.

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