(P-TS-65) Performance characteristics of a new multiplex blood screening assay on a fully automated system that detects 5 mosquito-borne viruses

Background/Case Studies: The Procleix ArboPlex assay is a new multiplex assay under development for use on the Procleix Panther® system. The assay is a qualitative Transcription-Mediated Amplification (TMA) nucleic acid test (NAT) designed to detect 5 arboviruses (arthropod-borne viruses) in plasma or serum specimens: chikungunya (CHIKV), dengue (DENV), Usutu (USUV), West Nile (WNV), and Zika (ZIKV) viruses. Transfusion-transmitted infections have been documented for DENV, WNV and ZIKV; the risk related to transfusion-associated CHIKV or USUV remains unclear.

Study

Design/Methods: Specificity was evaluated by screening 10,000 fresh individual donations from Spain and 1,839 16-donation pools collected in the US. The limit of detection (LoD) was determined with 3 reagent lots using WHO standards for WNV Lineage 1 (18/206), WNV Lineage 2 (18/208), ZIKV (11468/16), CHIKV (11785/16), as well as USUV and DENV Types 1-4 RNA in-vitro transcripts (IVTs). Results were analyzed by probit analyses (SAS 9.4) and compared to the commercially available monoplex Procleix assays.

Results/Findings: The ArboPlex Assay demonstrated 100% (95% CI: 99.96-100%) specificity for WNV (flasher channel) and 99.99% (95% CI: 99.94-100%) specificity for CHIKV, DENV, ZIKV (glower channel) in fresh individual specimens. The ArboPlex Assay demonstrated 100% (95% CI: 99.8-100%) specificity for WNV (flasher channel) and 100% (95% CI: 99.8-100%) specificity for CHIKV, DENV, ZIKV (glower channel) in fresh 16-sample pools. The 95% LoD values for the ArboPlex Assay were 3.8 International Units/mL (IU/mL) for WNV Lineage 1(18/206), 2.2 IU/mL for WNV Lineage 2 (18/208), 2.5 IU/mL for ZIKV (11468/16), and 7.7 IU/mL for CHIKV (11785/16). The 95% LoD was 33.4 c/mL for Usutu virus and 17.5 c/mL, 11.7 c/mL, 13.2 c/mL, 13.2 c/mL, for DENV Types 1-4 IVTs, respectively. The sensitivity of the ArboPlex assay was similar or improved compared to monoplex Procleix assays.

Conclusions: The ArboPlex assay on the Panther system demonstrated high specificity and sensitive detection of CHIKV, DENV, USUV, WNV, and ZIKV with overall comparable performance to individual Procleix assays. The assay may provide a flexible and sensitive solution for routine blood screening in geographic regions where arbovirus outbreaks may occur. Additionally, the ArboPlex assay may be useful for surveillance of arboviral activity by screening blood donors.

Importance of research: The Procleix ArboPlex assay is a new multiplex assay under development for use on the Procleix Panther® system that detects 5 mosquito-borne viruses that may pose a risk to blood safety. The assay may be useful in geographic regions where arbovirus outbreaks occur and may also become an important tool for surveillance of arboviral activity.