TABLE 5.
Results of the qualitative panel testing for the automated RPR tests and comparison to combined manual RPR/TP-PA data
| Status | Specimen n | Manual tests |
Automated RPR tests |
|||||||
|---|---|---|---|---|---|---|---|---|---|---|
| BioPlex RPR |
AIX 1000 |
ASI evolution |
||||||||
| RPR | TP-PA | n | R n (%) | NR n (%) | R n (%) | NR n (%) | R n (%) | NR n (%) | ||
| Syphilis staged specimens (n = 185) | ||||||||||
| Primary | 24 | R | R | 19 | 18a (100) | 0a (0) | 18 (94.7) | 1 (5.3) | 15k (78.9) | 4k (21.1) |
| NRr | R | 3 | 1 (33.3) | 2 (66.7) | 3 (100) | 0 (0) | 1l (33.3) | 2l (66.7) | ||
| NR | NR | 2 | 0b (0) | 1b (100) | 0 (0) | 2 (100) | 0 (0) | 2 (100) | ||
| Secondary | 43 | R | R | 41 | 37c (100) | 0c (0) | 40 (97.6) | 1 (2.4) | 39m (95.1) | 2m (4.9) |
| NR | R | 2 | 0 (0) | 2 (100) | 2 (100) | 0 (0) | 1 (50) | 1 (50) | ||
| Early latentq | 38 | R | R | 34 | 33 (97.1) | 1 (2.9) | 33 (97.1) | 1 (2.9) | 28 (82.4) | 6 (17.6) |
| NR | R | 4 | 1 (25) | 3 (75) | 1 (25) | 3 (75) | 1 (25) | 3 (75) | ||
| Early NPNS | 14 | R | R | 14 | 11d (84.6) | 2d (15.4) | 14 (100) | 0 (0) | 13 (92.9) | 1 (7.1) |
| Late latent | 66 | R | R | 56 | 47 (83.9) | 9 (16.1) | 54 (96.4) | 2 (3.6) | 52n (92.9) | 4n (7.1) |
| NR | R | 9 | 1 (11.1) | 8 (88.9) | 1 (11.1) | 8 (88.9) | 0 (0) | 9 (100) | ||
| R | NR | 1 | 0e (0) | 0e (0) | 1 (100) | 0 (0) | 1 (100) | 0 (0) | ||
| Syphilis specimens with unknown stage | 140 | R | R | 64 | 41f (82) | 9f (18) | 64 (100) | 0 (0) | 60o (93.8) | 4o (6.2) |
| NR | R | 76 | 7g (14) | 43g (86) | 16 (21.1) | 60 (78.9) | 11p (14.5) | 65p (85.5) | ||
| Syphilis cases combined (staged and unknown) | 325 | R | R | 228 | 187a,c,d,f (89.9) | 21a,c,d,f (10.1) | 223 (97.8) | 5 (2.2) | 207 (90.8) | 21 (9.2) |
| NR | R | 94 | 10g (14.7) | 58g (85.3) | 23 (24.5) | 71 (75.5) | 14 (14.9) | 80 (85.1) | ||
| R | NR | 1 | 0e (0) | 0e (0) | 1 (100) | 0 (0) | 1 (100) | 0 (0) | ||
| NR | NR | 2 | 0b (0) | 1b (100) | 0 (0) | 2 (100) | 0 (0) | 2 (100) | ||
| Nonreactive or not diagnosed with syphilis | 409 | R | NR | 2 | 1h (100) | 0h (0) | 1 (50) | 1 (50) | 2 (100) | 0 (0) |
| NR | R | 1 | 1 (100) | 0 (0) | 0 (0) | 1 (100) | 0 (0) | 1 (100) | ||
| NR | NR | 406 | 7 (2.8)a,j | 240i,j (97.2) | 1 (0.2) | 405 (99.8) | 5 (1.2) | 401 (98.8) | ||
| Total | 734 | -s | - | 734 | 206a-i (39.2) | 320a-i (60.8) | 249 (33.9) | 485 (66.1) | 229 (31.2) | 505 (68.8) |
Reagents were not available to test 208 specimens under described categories as “a” (n = 1), “b” (n = 1), “c” (n = 4), “d” (n = 1), “e” (n = 1), “f” (n = 14), “g” (n = 26), “h” (n = 1), and “i” (n = 159) were excluded from data calculation.
Two specimens gave errors during testing; were repeatedly tested, gave nonreactive results and were added into “NR” (238 + 2 = 240).
One specimen gave NR result; upon repeated testing it again gave NR result (repeated due to technical error).
One specimen gave NR result; upon repeated testing it again gave NR result (repeated due to technical error).
Three specimens gave NR results; upon repeated testing two gave R result and were added into “R” (37 + 2 = 39) (repeated due to technical error).
Three specimens gave NR results; upon repeated testing two gave R and were added into “R” (50 + 2 = 52) (repeated due to technical error).
Four specimens gave NR results; upon repeated testing one gave R results and were added into “R” (57 + 3 = 60) (repeated due to technical error).
Five specimens gave NR results; upon repeated testing one gave R results and were added into “R” (10 + 1 = 11) (repeated due to technical error).
Early NPNS = early nonprimary nonsecondary syphilis; RPR = rapid plasma reagin; TP-PA = T. pallidum particle agglutination; R = reactive; NR = nonreactive; n = number; % = percentage; PPA = positive percent agreement; NPA = negative percent agreement.
Gray cells represent discordant RPR/TP-PA results.
-, no data.