Recent upgrades to WCBS nucleic acid amplification testing (NAAT) provide improved sensitivity and specificity for HIV-1 RNA, HIV-2 RNA, HBV DNA and HCV RNA. The reduction in false positives and subsequent repeat and confirmatory testing improves laboratory efficiency and turnaround time. Thus, fully tested blood products are labelled, released into the blood supply and distributed to Blood Banks sooner, where they are needed for issuing to patients.
The NAAT assay uses transcription-mediated amplification technology to detect early viral infection. In addition to this, the Transfusion Virology Laboratory tests every donation for HIV-Ag/Ab, Anti-HCV and HBsAg, and the Red Cell Serology Laboratory conducts routine donation syphilis testing. All tests must be non-reactive in order for a blood product to be labelled.
In the past 3 financial years, WCBS has confirmed the following positive donor test results:
| 2019/2020 | 2020/2021 | 2021/2022 | |
| Hepatitis B | 70 | 85 | 78 |
| Hepatitis C | 5 | 7 | 8 |
| HIV | 62 | 52 | 56 |
| Syphilis | 84 | 81 | 115 |
In the event that a donor may test positive for one of these infections, WCBS will provide counselling or referral. An algorithm is followed before a final decision is made to resign a donor, or decide if the donor maybe be eligible for reinstatement.
For more information about transfusion virology testing, contact Nadia Pietersen, Manager – Transfusion Virology (Nadiap@wcbs.org.za)