SWAB -IMPACT

The challenge

Diagnosis of tuberculosis disease remains an enduring challenge. Of the 10 million people who develop TB each year globally, only around one in four receive a diagnosis. The ‘missing millions’ are not treated effectively and continue to transmit TB in the community.

Detection of cases has improved following the widespread introduction of molecular testing platforms, such as Gene Xpert. However, these are expensive and are typically based in centralised facilities, leading to delays in testing and lost contact with patients. Furthermore, testing typically relies on sputum samples. These can be difficult to obtain, particularly from young children and people living with HIV.

Rapid point-of-care tests for TB could therefore have an enormous impact by ensuring that newly diagnosed patients begin treatment promptly. 

The project

The SWAB-IMPACT project is evaluating a possible solution to this challenge: a newly developed rapid point-of-care diagnostic platform, PlusLife MTB, which has the potential to be used on non-sputum samples (simple tongue swabs).

The PlusLife device has been shown to be highly usable, relatively affordable, and capable of delivering good performance – similar to Xpert Ultra on sputum samples, with only slightly lower performance on tongue swabs. The SWAB-IMPACT project is collecting the first evidence on its use in the field in high-burden settings.

The project is evaluating the PlusLife test in a cluster randomised trial in South Africa and Zambia. In clusters, tuberculosis programmes will either use standard methods to assess potential TB patients (referral to a regional lab for molecular testing) or an adapted pathway including the use of a PlusLife test. Both sputum-based and tongue-swabbing approaches will be assessed. The key outcome will be the number and proportion of patients who complete testing, have confirmed TB, and begin treatment within seven days. 

During the trial, the project will also assess the feasibility and acceptability of implementing PlusLife testing by engaging key stakeholders, including patients, healthcare workers, and programme managers. Potential financial implications and cost-effectiveness will also be explored. 

Impact

The SWAB-IMPACT project could have a radical impact on the detection of tuberculosis cases. It will:

• Provide high-quality evidence on the clinical utility of the PlusLife platform for detecting TB cases.
• Identify potential barriers and enablers of implementation and generate an implementation toolkit to aid wider introduction.
• Provide an indication of the potential cost implications of routine PlusLife MTB use.

More efficient detection of cases could have a profound impact on TB control, ensuring more patients begin treatment, reducing transmission and lowering the colossal TB disease burden, which disproportionately affects the poorest countries and communities.