New Rapid-fire Diagnosis Of TB

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The Minister of Health, Aaron Motsoaledi, and NHLS
CEO, Sagie Pillay, talking to staff at Prince Mshiyeni lab

On World TB Day on 24 March, Minister of Health Aaron Motsoaledi unveiled the high-tech GeneXpert tuberculosis (TB) diagnostic instrument at the NHLS’ Prince Mshiyeni Hospital laboratory in KwaZulu-Natal.

South Africa is the first African country to have introduced the GeneXpert for TB diagnosis and only the fourth outside the USA. In a joint project between the NHLS and the Department of Health (DoH), the DoH budgeted R48 million to install GeneXpert instruments in facilities in all nine provinces; NHLS will supply the testing service free of charge to the provinces.

Led by Professor Wendy Stevens and Dr Gerrit Coetzee, staff at the relevant laboratories worked around the clock to meet very tight deadlines to be ready for the launch on World TB Day. “Their dedication, commitment and skills showed that NHLS staff can meet any challenge,” says Sagie Pillay, CEO.

GeneXpert provides high quality diagnostic results, in particular providing value for smear negative individuals which have presented clinicians with huge diagnostic difficulties and significant delays in culture.

This new technology has reduced the turnaround time of diagnosing TB, including identification of rifampicin resistance, to two hours, thus enabling better access to anti-TB treatment; this is likely to reduce mortality due to TB and reduce transmission of TB in communities. In addition, a rapid screen for multi-drug resistance will ensure that the right treatment is administered. The rapid diagnosis of TB will also enable anti-retroviral treatment to be initiated faster and appropriately in those co-infected.

The assay comes in small and large formats. The large instrument, suitable for high-volume laboratory settings – as demonstrated at Prince Mshiyeni laboratory – can process 48 TB tests in a two-hour session. The smaller machines are able to do either 1, 4 or 16 tests per day and will be easy for clinicians/nurses to use in the clinic; these machines have been installed in TV ‘hotspots’ such as Tugela Ferry in KwaZulu-Natal. In phase I of the GeneXpert roll-out, 23 instruments have been placed in NHLS laboratories throughout the nine provinces. More will be placed in phase II.

Laboratory staff are extremely excited by the rapid results and simplicity of the technology. Local studies have demonstrated that the assay is accurate with good sensitivities and specificities. Further experience has demonstrated that the test can be used to diagnose extra-pulmonary TB. Studies are underway to assess its value in the paediatric population.

According to Mr Pillay the GeneXpert is an excellent but expensive TB diagnostic option but if implemented appropriately by maximum time usage and staff deployment, it can be a cost-effective method. “Another challenge that I believe the committed NHLS staff will meet,” Mr Pillay says.