Evaluation of Chagas Blood Screening and Confirmatory Assays

• ABBOTT PRISM Chagas Assay and Chagas Confirmatory Assay (Device): Test blood donor sample with ABBOTT PRISM Chagas assay. If results are reactive, donor sample will be tested with Chagas Confirmatory assay. Donors reactive with screening assay or positive with confirmatory assay will be deferred and asked to return for a follow-up blood draw.
• ABBOTT PRISM Chagas Assay and Chagas Confirmatory Assay (Device): Test blood donor sample with investigational Chagas assay. If results are reactive, donor samples will be tested with Chagas confirmatory assay. Donors reactive with screening assay or positive with confirmatory assay will be deferred and asked to return for a follow-up blood draw.

Primary outcomes

• PRISM Chagas Specificity [6 months]: Total of 16,249 serum and plasma blood donor specimens tested with PRISM Chagas assay during design validation phase. Repeatedly reactive specimens were tested further with a supplemental assay \[radioimmune precipitation assay (RIPA)\].
• PRISM Chagas Sensitivity [6 months]: Specimens from subjects known to be T cruzi parasite positive were tested with PRISM Chagas assay.
• ESA Chagas Specificity [3 months]: Preselected US blood donor specimens (330) presumed T cruzi antibody negative negative that were tested only with the investigational ESA Chagas.
• ESA Chagas Sensitivity [3 months]: Specimens from individuals known to be T cruzi parasite positive were tested with ESA Chagas assay.

Secondary outcomes

• PRISM Chagas Reactivity Serology Positive Specimens [4 months]: Total of 85 specimens from subjects from South America known to be positive for T cruzi antibodies and 202 US blood donor specimens that were repeatedly reactive on a licensed test for antibodies to T cruzi were tested with the PRISM Chagas assay and supplemental testing (RIPA).
• PRISM Chagas Reactivity in Chagas Endemic Population [2 months]: Population of specimen collected in Chagas endemic area in South/Central America (524) were tested to demonstrate reactivity with the PRISM Chagas assay in a population with a 5% or greater prevalence of infection with T cruzi antibody. specimens tested with PRISM Chagas assay and licensed test for T cruzi antibody and if repeatedly reactive with either assay the specimens were tested with supplemental assay (RIPA). Data presented with PRISM Chagas and RIPA results.
• ESA Chagas Testing of US Blood Donor Specimens Repeatedly Reactive by ABBOTT PRISM Chagas. [15 months]: A total of 41,760 US blood donor specimens were tested by ABBOTT PRISM Chagas. Of these specimens, 58 out of 79 specimens were T cruzi antibody repeatedly reactive by ABBOTT PRISM Chagas (26 from 16,249 donor specimens tested in design validation phase and 32 from 25,511 specimens from the Chagas extended evaluation). Donor specimens that were repeatedly reactive with the licensed T cruzi antibody assay, but PRISM Chagas nonreactive (6) and specimens PRISM Chagas grayzone negative (15) were excluded from this analysis.
• ESA Chagas Sensitivity in Serologically Positive Non-US Specimens [3 months]: ESA Chagas Sensitivity in a non-US population was determined for the 85 out of the total 287 serologically positive specimens (202 US Serology Positive specimens were excluded). These specimens were collected from individuals positive for T cruzi antibodies based on 2 different serologic tests for antibodies to T cruzi in Argentina and were tested with ESA Chagas.
• ESA Chagas Testing in Chagas Endemic Population [2 months]: Specimen collected in Chagas endemic areas in South or Central America (524) tested with ESA Chagas and licensed test for T cruzi antibody. Specimens repeatedly reactive with either screening assay and/or ESA Chagas positive were tested with supplemental assay (RIPA). Presentation of ESA Chagas results for 132 specimens from a Chagas endemic population that were RIPA positive.

Sex: All, ages: 18 Years to any, accepts healthy volunteers

Inclusion Criteria:

* Healthy donors that have consented to participate in study

Exclusion Criteria:

* N/A

Participant flow

Outcome results

• PRISM Chagas Specificity (Primary), Number, participants: ABBOTT PRISM Chagas Specificity 23
• PRISM Chagas Reactivity Serology Positive Specimens (Secondary), Number, participants: Reactivity T Cruzi Antibody Positive 224
• PRISM Chagas Sensitivity (Primary), Number, participants: Sensitivity Chagas Parasitology Positive Specimens 0
• PRISM Chagas Reactivity in Chagas Endemic Population (Secondary), Number, participants: PRISM Chagas Reactivity Endemic Population 129
• ESA Chagas Testing of US Blood Donor Specimens Repeatedly Reactive by ABBOTT PRISM Chagas. (Secondary), Number, participants: ESA Chagas US Donor Specimen Testing 9
• ESA Chagas Specificity (Primary), Number, participants: ESA Chagas Specificity 327
• ESA Chagas Sensitivity (Primary), Number, participants: Sensitivity Chagas Parasitology Positive Specimens 110
• ESA Chagas Sensitivity in Serologically Positive Non-US Specimens (Secondary), Number, participants: ESA Chagas Non-US Serologically Positive 85
• ESA Chagas Testing in Chagas Endemic Population (Secondary), Number, participants: Reactivity in Chagas Endemic Population 130

Adverse events

Time frame: Adverse event data collected during donor follow-up collection for period of 10 months. Donors reactive with screening assay or positive with confirmatory assay will be deferred and asked to return for a follow-up blood draw.

• Susan Stramer, PhD, Principal investigator, American National Red Cross
• Sharon Gordon, Principal investigator, Lifesource
• Norman Kalmin, MD, Principal investigator, South Texas Blood and Tissue Center
• Carolyn T Young, MD, Principal investigator, Rhode Island Blood Center
• Deborah Williams, Principal investigator, Florida Blood Services
• Pauline Simmonds-Brown, Principal investigator, Blood Net USA