Tuberculosis is one of those diseases that might not seem so serious but can be quite fatal.

Despite being both curable and preventable, Tuberculosis killed 1.23 million people in 2024, with an estimated 10.7 million falling ill globally that year alone.

Africa carries a large share of that weight with 17 of the 30 countries having the highest TB burdens are in the WHO African Region, including South Africa, the Democratic Republic of Congo and Nigeria.

South Africa, in particular, has made hard-won progress. It is one of a small number of high-burden countries estimated to have achieved a 50 per cent reduction in TB incidence since 2015.

Although, tens of thousands of people are still being missed every year.

According to the WHO Global TB Report 2024, an estimated 58,290 people with TB in South Africa were still unaccounted for in 2023.

The gap is a serious and structural one.

Why Detection Is Still Failing

In much of sub-Saharan Africa, TB screening requires specialist clinicians, X-ray infrastructure and laboratory access, and most of these needs are not evenly distributed.

The people closest to patients in underserved areas, which oftentimes are the medical practitioners, are often the first point of contact but are routinely left without the diagnostic tools to act on what they encounter.

This is the gap that Cape Town-based startup AI Diagnostics is trying to close.

Founded in 2020 by Braden van Breda, Johan Coetzee and Mark van Breda, the company has built a product stack that puts TB screening capability directly in the hands of frontline workers who have traditionally been bypassed by the medical device industry.

Ostium, the company's flagship product, is a digital stethoscope that works in hand with a proprietary AI model called AI.TB to detect tuberculosis through the analysis of lung sounds in real time, at the point of care and without specialist equipment.

The logic is to listen to the lungs, let the algorithm flag what sounds like TB and refer the patient for confirmatory testing before the window closes.

The New Stethoscope

AI.TB is changing the stethoscope by giving it a second brain.

When a health worker uses the Ostium device, the AI model listens for acoustic patterns associated with TB infection.

If the signals are present, the patient is immediately referred for diagnostic testing, cutting out the delay that often allows early-stage TB to become something far harder to treat.

CEO Braden van Breda said it changes the availability and the geography of screening for health systems trying to close the detection gap.

Regulatory approval from the South African Health Products Regulatory Authority (SAHPRA) has already been secured, and the company has screened over 1,000 patients domestically which is a proof-of-concept that has been enough to attract serious investment attention.

The $5 Million Vote of Confidence

In April 2026, AI Diagnostics announced it had raised ZAR 85 million, approximately USD 5 million, in a pre-Series A round led by The Steele Foundation for Hope, with participation from the iFSP Group, the Global Innovation Fund, Africa Health Ventures and Savant.

The CEO of The Steele Foundation, Joe Exner said the company exemplified why backing technical entrepreneurs closest to the problems they are solving matters.

Africa Health Ventures managing partner, Rowena Luk, went further, noting that the stethoscope as a medical instrument has been essentially static for more than a century, and that AI Diagnostics could be at the forefront of its evolution.

The funding will go toward clinical validation, continued AI model development and building the operational infrastructure needed to scale across Sub-Saharan Africa and Asia, with clinical research already extending across more than 10 countries in both regions.

A Commercial Bet on a Global Health Crisis

Van Breda has noted that TB has historically been underfunded relative to its burden precisely because it affects largely the low- and middle-income populations.

Global funding for TB prevention, diagnosis and treatment reached only USD 5.9 billion in 2024, less than one-third of the global target, and cuts to Global Fund and US government grants are already disrupting screening and diagnosis chains across high-burden African countries.

What AI Diagnostics is stating, through its funding round and its expansion ambitions, is that global health challenges are viable commercial opportunities and that the tools to address them do not have to be invented in Geneva or California.

They can come from Cape Town.

The real test will not be whether Ostium works in controlled clinical settings. It will be whether it can hold up in all areas and whether the health systems those places belong to are funded well enough to act on what the algorithm finds.

That is a structural question that no stethoscope, however intelligent, can answer alone.

But in a fight where early detection is the difference between a cured patient and a statistic, having better tools in more hands makes a significant difference.