Ortho T. Cruzi ELISA Test System
The Ortho T. cruzi ELISA Test System is an enzyme-linked immunosorbant assay for the qualitative detection of antibodies to Trypanosoma cruzi (T. cruzi) in human serum and plasma specimens.
This product is intended for use as a donor screening test to detect antibodies to T. cruzi in plasma and serum samples from individual human donors, including donors of whole blood, blood components or source plasma, and other living donors. It is also intended for use to screen organ and tissue donors when specimens are obtained while the donor's heart is still beating. This test is not intended for use on specimens from cadaveric (non-heart-beating) donors. This test is not intended for use on samples of cord blood.
The Ortho T. cruzi ELISA Test System is intended for use in a fully manual mode, in semi-automated mode using the Ortho Summit™ Sample Handling System (Summit) or in automated mode with the Ortho Summit™ System (OSS).
This assay is not intended for use as an aid in diagnosis.
Performance by Design
Six Sigma assay design and manufacturing process
Fully automated on the Ortho Summit™ System
Full Lysate antigen set – excellent sensitivity to geographic strains
Low concentration of enzyme conjugate – lower cross-reactivity
Ultra-low signal with negative donations – excellent specificity
|
Observed Sensitivity * |
|
Parasite-Positive Population
Bolivia, Chile, Colombia, and Nicaragua |
100% [106/106 Reactive (95% CI: 96.6 - 100.0%]) |
|
Serological-Positive Population
Bolivia, Brazil, Chile, Guatemala, |
100%
[662/662 Reactive] |
|
High-Risk Populations **
Bolivia, Colombia, Guatemala, Mexico, and Nicaragua |
98.9%
[92/93 Reactive (95% CI: 94.2 – 100.0%)] |
* Source: Performance study data, see Package Insert for details.
** The observed specificity of the ORTHO T. cruzi ELISA Test System in the High-Risk population in this study was 99.4% (478/481) with a 95% confidence interval of 98.2% to 99.9%. |
The New Industry Benchmark for Specificity*
Two performance studies were conducted on a total of 70,7602 serum and plasma donations using the Ortho Summit™ System.3
Observed seroprevalence of 1 in 3010 in volunteer US blood donors tested from high risk areas (n = 30095).
|
Observed Specificity 99.997% (95% CI: 99.982 - 100.000%)2 |
|
Observed ELISA Results |
Positive4 |
Negative4 |
Indeterminate4 |
Total4 |
|
Reactive |
9 |
2 |
0 |
11 |
|
Non reactive |
1# |
70748 |
0 |
70749 |
|
Total |
10 |
70750 |
0 |
70760 |
|
In a performance study, 616 potentially cross reacting samples were tested. In the 516 non-Leishmania samples, specificity was 99%. 74 of the 100 Leishmania samples were reactive and the test may yield falsely reactive results with old world Leishmania samples.
*Compared to all currently licensed serology Donor Screening assays in North America - data on file
1Performance study data, see Package Insert for details and 95% CI
2Performance study data (n = 40,665) Prevalence Study (n=30095), see Package Insert for details and 95% CI claims
3 See Package Insert for Serum and Plasma and 95% CI claims
4Based on RIPA Supplemental Test
#Sample initially non-reactive, S/Co 0.964. Both repeats tests were reactive ,S/Co 1.204 and 1.084)
Precautions
CAUTION: Some components of this kit contain human blood derivatives. No known test method can offer complete assurance that products derived from human blood will not transmit infectious agents. Therefore, all blood derivatives should be considered potentially infectious. It is recommended that these reagents and human specimens be handled using established good laboratory working practices
Limitations
Because the Ortho T. cruzi ELISA Test System was designed to screen individual units of blood or plasma, most data regarding its interpretation were derived from testing individual specimens. Insufficient data are available to interpret tests performed on other body fluids including cadaveric fluids, pooled blood, or processed plasma and products made from such pools; testing of these specimens is not recommended.
A nonreactive test result does not exclude the possibility of exposure to T. cruzi. Levels of antibodies to T. cruzi may be below the detectable limit of the assay or undetectable during an early stage following exposure to T. cruzi.
For up-to-date professional educational materials about Chagas’ Disease, please visit www.Ortho-WIRE.com