Table 5.
Breakdown of hepatitis B marker (anti-HBc, HBsAg, HBV NAT) test results among first-time donors (2005–2020).
| 9 April 2005 to 28 February 2011 |
1 March 2011 to 31 December 2020 |
Total | |
|---|---|---|---|
| Number of first-time CBS donors | 507,165 | 894,438 | 1,401,603 |
| Type of hepatitis B screening test performed on first-time CBS donors | Overall number of hepatitis B screening tests performed on first-time CBS donors (% positive) | ||
| Anti-HBc | 507,165 (1.31) | 894,438 (1.41) | 1,401,603 (1.37%) |
| HBsAg | 507,165 (0.07) | 894,438 (0.05) | 1,401,603 (0.056%) |
| NAT 1 | 6681 (5.03) | 894,438 (0.05) | See footnote 1 |
| Hepatitis B screening test | Number of first-time CBS donors testing positive (Percent of positive tests %) | ||
| Anti-HBc only 2 | 6252 (1.23) | 12,108 (1.35) | 18,360 (1.31%) |
| NAT only 3 | ----- | 2 (0.0002) | See footnote 1 |
| HBsAg only 4,5 | 5 (0.001) | 4 (0.0006) | 9 (0.0006%) |
| Anti-HBc and HBsAg only 4 | 40 (0.008) | 39 (0.004) | 79 (0.006%) |
| Anti-HBc and NAT only 2 | 33 (0.007) | 28 (0.003) | 61 (0.004%) |
| HBsAg and NAT only 4,5 | 1 (0.01) | 1 (0.0001) | 2 (0.0001%) |
| Anti-HBc and HBsAg and NAT 4 | 302 (0.06) | 395 (0.04) | 697 (0.05%) |
| All positive anti-HBc tests | 6627 (1.31%) | 12,570 (1.41%) | 19,197 (1.37%) |
| All positive HBsAg tests | 348 (0.07%) | 439 (0.05%) | 787 (0.056%) |
| All positive NAT 1 tests | See footnote 1 | 426 (0.05%) | See footnote 1 |
1 NAT testing was supplementary prior to 28 February 2011; 2 likely occult/resolved infections (clinical scenarios 1,3); 3 likely incident infections; 4 likely chronic infections (clinical scenario 2); 5 potentially false positive (occurs when original signal is near cut-off with “false” neutralization). Note: Seven samples that were HBsAg repeat reactive did not complete confirmatory testing. However, they were repeat reactive for anti-HBc and therefore, were considered HBsAg positive and classified as likely chronic infections.