Tech key to combating drug-resistant TB in Africa, experts advise

A TB patient receiving counseling and treatment at Kerugoya Hospital TB Management Center. [Jane Mugambi, Standard]

African countries should increase their investment in Tuberculosis and especially in newer interventions that can help limit the spread of drug-resistant TB.

Belinda Ngongo, the global health director at Illumina, says with the significant gap in the funding needed to combat tuberculosis, there is a need to make savings in the long run for healthcare systems.

Illumina regional marketing manager Amadou Gueye added that routine TB drug resistance surveillance and drug-susceptibility testing (DST) are critical to combat the global TB epidemic. DST helps determine appropriate TB treatment regimes.

Speaking after a webinar on TB eradication, Gueye said: “Conventional methods such as culturing the mycobacteria that cause TB are slow and can take up to two months to see what treatments are effective against the disease.”

With targeted next-generation sequencing (tNGS), this can be done within days. It is a fast, sensitive, scalable and culture-free method that provides a comprehensive anti-TB drug resistance profile, Gueye adds.

Managing drug-resistant TB is complex, with more than 20 drugs used to treat patients in various combinations, a situation that has pushed scientists to consider technological solutions in the fight against the disease.

In February, experts at the Kenya Medical Research Institute undertook the development of a mobile phone application that uses artificial intelligence to diagnose tuberculosis and other respiratory disorders.

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“This software kind of uses artificial intelligence to analyse coughs – we call them the cough spectral grams – and then it regresses them. It is a mathematical way of modelling the cough image to determine whether there is a difference between someone with TB when they cough and someone without TB when they cough,” Dr Videlis Nduba told journalists at the time.

The latest World Health Organisation guidelines have introduced new treatment regimens for drug-resistant TB.

These regimens include new and repurposed drugs that can help to reduce the duration of treatment from two years to just six months. But, there are concerns. According to Gueye, drug resistance will happen for these new drugs and “in fact it’s already happening, so it is crucial to preserve the efficacy of these highly promising drugs through timely and comprehensive resistance testing”.

Next-generation sequencing can also support national TB programmes in Africa in an effort to monitor drug-resistant TB by knowing which strains of bacteria are circulating and ultimately reduce the risk of transmission in the community.

Gene mutations

Asked how technology can help in identifying and tracking the spread of drug-resistant TB strains, Gueye said genomic technology can accurately predict drug resistance, looking at the numerous gene mutations that are known to cause resistance to anti-TB drugs.

Combined with complementary data such as clinical, geographic, and demographic information, genomics, Gueye says, can be a powerful tool for decision making in drug-resistant TB management.

Regarding public health interventions, using a genomic based approach will help to better investigate outbreaks and circulation of drug resistant strains.

Jarim Omogi, an Amref International University public health researcher, says any technological advancements that can save time and cost of diagnosis are embraced.

Omogi added that the “use of AI in medicine” is growing.

“The AI and all these applications are basically to activate and help more so in confirmation and two in real time data, so that the patient can be helped fast. How cost effective is it? How fast is it? How cheap is it? That is the benefit of such.”

Partnerships with local authorities and researchers have been fronted as ways to enhance the detection and treatment of TB in Africa.

In 2023, Illumina and GenoScreen entered a strategic partnership for distribution and technical support in low- and middle-income countries.

With such programmes, local scientists are trained on genomics so they can apply it to health issues affecting the continent.

Ngongo agrees, adding that several African countries are embracing targeted next-generation sequencing (tNGS) for TB control.

South Africa, Nigeria, and Eswatini, she says, are leading the charge.

Ngongo cited South Africa’s Dr. Shaheed Vally Omar at the Centre for Tuberculosis - National Institute for Communicable Diseases for being instrumental in championing tNGS.

“As genomic tools become more widely implemented across African countries, tNGS is poised to significantly impact TB control over the next decade,” Ngongo said.

Cost considerations

Implementing tNGS in resource-limited settings requires a balanced approach to cost considerations.

This includes factoring in the healthcare costs associated with delayed or inaccurate diagnoses, such as prolonged illness and increased transmission.

Cost-effectiveness analyses commissioned by the WHO have demonstrated the value of tNGS in high TB burden countries like India and South Africa, where it has proven cost-effective and led to more health gains than current drug susceptibility testing practices.

Ngongo said integrating tNGS into existing infrastructure and utilising sequencing platforms for multiple diseases can further optimise resources.

“Additionally, multisectoral engagement with international organisations, donors, funding agencies, and the private sector can unlock additional resources and expertise,” the director added.

But not all may be on board regarding tNGS. Ngongo says genomic sequencing is relatively new in the tool kit for TB management and countries will have to follow a stepwise approach.

Policies and regulations

Ngongo went on: “For a country to adopt any new technology in public health, it’s important to make sure it’s proven to work and fit for purpose.”

The World Health Organisation evaluates various sequencing solutions before issuing official recommendations to countries.

The expertise of laboratory specialists in genomics can be limited in some countries as there are steps and procedures that are specific to sequencing. “Increasing this expertise will be critical for successful implementation,” she said.