In South Africa, tuberculosis (TB) is one of the leading causes of death. Although it is curable, there are thousands of people who have TB but have not yet been diagnosed and are therefore left untreated. This presents a serious problem not just for the patient but for those they are in contact with, as the virus is airborne and easily transferable from one person to another.

In 2013 MARTI TB Diagnostic – a tenant of The Innovation Hub – won first place in the Gauteng Accelerator Programme (GAP) Innovation Awards for their blood-based TB test in the bioscience category. The GAP Biosciences programme was designed to assist scientists and entrepreneurs to pursue opportunities for their cutting-edge bioscience technologies. Since its inception, MARTI TB has worked ambitiously to solve the health challenge posed by TB.

The challenge

The majority of commercially-utilised TB diagnosis techniques require sputum which is collected by inducing coughing. This technique can be unappealing as it poses a significant risk to healthcare workers due to the infectious nature of TB bacteria. Additionally, it is difficult to obtain sputum from children and HIV-infected patients, and 16% of patients have TB occurring outside of their lungs, making it hard to detect and commonly resulting in fatality.

Sputum sampling also takes several weeks to yield results which means that patients spend a longer time without a diagnosis and without treatment. MARTI TB has been developing a blood-based TB test which will only require a single drop of blood.

How it works

The human body’s best-known protective antibody response to most infectious agents is directed to protein antigens. Production of antibodies to protein antigens is facilitated by antibody‐producing B‐cells that display the antigen first to CD4 “helper” T‐cells. Helper T‐ cells are targeted and paralysed by HIV.

In TB patients, antibodies are directed also to lipid (fat‐based) antigens such as mycolic acid. B-cells that produce antibodies directed to lipid antigens do not require help from CD4 T‐cells, hence providing an alternative pathway of antibody generation that is not affected by HIV co‐infection. Therefore, concerns about TB diagnosis using blood‐based detection of antibodies do not apply to the MARTI test.

Why it’s better

The MARTI test can be used to screen large populations such as in schools and prisons, as well as migrants and travellers at the point of entry, ensuring the reduction of the spread of TB. This is made possible by its inherent ability to yield a diagnostic result in less than an hour at the point of care. The required handheld instrument and consumables are easily portable to remote and rural health facilities. This diagnostic system has the potential to bring about significant savings in the public healthcare system by providing an efficient and speedy analysis that does not require patient hospitalisation.

More funding needed

Significant progress has been made with the development of a screen-printed electrode coated with the applicable antigen, mycolic acids. The most expensive part of developing the point-of-care instrument is to develop the disposable microfluidic cartridge in which the electrodes must be embedded. MARTI TB Diagnostics is in the process of refreshing their five-year business plan in order to raise enough funding for this part of the development, as the company feels strongly that their solutions can contribute to the health and wellness of South Africans.