Table 3.
Diagnostic evaluation of microsphere array assays for HeV detection.
| Microsphere array assay (archival RNA) |
HeV qPCR assaya | ||
|---|---|---|---|
| (original diagnostic results) | |||
| Positive | Negative | Indeterminate | |
| Henipa N-gene positive | 72 | 4 | 4 |
| Henipa N-gene negative | 5b | 57 | 3 |
| Total (n = 145) | 77 | 61 | 7 |
|
| |||
| Henipa P-gene positive | 65 | 2 | 1 |
| Henipa P-gene negative | 12b | 57 | 6 |
| Total (n = 143)c | 77 | 59 | 7 |
Retrospective analysis of results from microsphere array assays on archival RNA of diagnostic submissions in comparison with original qPCR diagnostic results. Preliminary cut-off values (241 MFI for the N-gene and 518 MFI for the P-gene) were derived from results of the negative horse population.
(a) HeV qPCR negatives include presumed HeV negative samples.
(b) Five samples categorised HeV qPCR positive in the originally diagnostic assay were negative in both Henipa N- and P-gene assay of archival RNA. All five samples were HeV negative when archival RNA was retested by qPCR (indicating likely degradation of the archival RNA in these samples).
(c) Two samples from the presumed HeV negative population were not available for the henipa P assay.