The National Health Services Laboratory (NHLS) is slowly reducing South Africa’s Covid-19 test backlog but has been hampered by international shortages, says Dr Kamy Chetty, chief executive officer.
Presenting to parliament on Wednesday (10 June), Chetty said that the backlog currently stands at around 63,000 unprocessed specimens. These are defined as specimens which are older than three days from when they were first registered at the laboratory.
Chetty noted that a reasonable time to clear a sample through the laboratory, if all reagents (test kits) and resources are available, is between 48-72 hours.
She added that the NHLS is making steady progress in reducing the backlog which stood at over 80,000 specimens at the start of June.
The below table shows how the backlog is decreasing in more detail.
When looking at the backlog at a provincial level, Chetty said that the biggest backlog is currently seen in Gauteng (23,000) followed by the Eastern Cape (21,953).
The Western Cape, which accounts for two-thirds of the country’s coronavirus cases, has a testing backlog of 7,266 as of Monday.
Chetty said that the NHLS’ testing strategy is prioritised according to the following categories and will be identified on the request form through colour coding:
- Category 1 (Red): Prioritise testing for those with a medical need and for clinical diagnosis;
- Category 2 (Orange): Testing for high-risk individuals;
- Category 3 (Yellow): Testing of critical frontline workers and essential service personnel;
- Category 4 (Green): Surveillance;
- Category 5 (Blue): Screening in targeted hotspots.
As of 8 June, the NHLS has conducted 492,704 tests, said Chetty.
She noted that the NHLS has increased the number of tests done each month with a massive increase in the number of tests being performed during the month of May where the figures more than doubled between April and May.
Chetty added that 105,023 tests were conducted in the first week of June alone.
Chetty said that the NHLS’ testing capacity is based on the kits used across its laboratories.
She noted that ‘BioRad’ with different kits can conduct 5,000 tests in around 24 hours. By comparison, the newer GeneXpert kits can conduct closer to 15,000 in the same amount of time.
Despite the big jump in testing, Chetty said that the NHLS is also working on a strategy to upscale the number of tests it conducts. This strategy includes:
- Increasing extraction equipment and diversifying platforms to have multiple suppliers;
- Exploring alternative methods of extraction;
- Advocating for a better supply of test kits for higher throughput machines;
- More targeted and focused testing to allow better use of limited resources;
- Use of rapid diagnostic serology tests;
- Use of spare capacity in the private sector (limited);
- Use of spare capacity in the academic sector (limited).