/ 10 July 2015

The anti-bug superhero

Dr Grant Theron is changing the fighting TB process
Dr Grant Theron is changing the fighting TB process

When we’re little, many of us have dreams of doing something big, something that will change the way that things are done, something that will save people. Most of us grow up and follow the paths of those before us, choosing something safe and sensible. 

Not so for Dr Grant Theron, whose game-changing career in fighting tuberculosis (TB) was founded on a lifelong interest in biology and science — spiced up by a fascination in genetic engineering nurtured by reading too much science fiction when he was young. 

This combination led to him completing a BSc (first class) and BSc (honours) from the University of Cape Town (UCT), followed by an MSc at University College London.

He opted for a commercially oriented project for his doctoral studies, completing his PhD in molecular and cell biology at UCT, but regretted using his hard work and skills towards something that would “just make a rich company richer”. 

Theron then decided to work in human health, with a particular focus on TB, which is a major killer of young adults in the developing world. He is currently associate professor at the DST/NRF Centre for Excellence in Tuberculosis Research at the University of Stellenbosch.

“Despite TB being a treatable, curable disease, TB control has failed in South Africa, and is increasing on an alarming scale in countries such as India,” says Theron. “The diagnosis of TB takes longer than it should, and most patients with TB never even enter the healthcare system — they die untreated in their community, after they’ve transmitted the disease to many other people.

“We are working to develop diagnostics that make it possible for patients to be diagnosed and start TB treatment potentially on the very same day of their first clinical encounter,” he says. “What’s more, these tests can be done by a minimally trained healthcare worker.”  

The placement of tests at the point-of-care — rather than at central laboratories — will reduce the number of patients who are diagnosed but don’t start treatment, and will increase the number of cases diagnosed, reducing time to treatment initiation, and hence improving clinical outcomes.

Such tests should also be useful for active case finding where diagnosticians seek patients in the community, rather than waiting for already very sick patients to present to clinics. “Another issue is drug-resistant TB (DR-TB) which, despite comprising less than 5% of TB cases, consumes  over 40% of the total national TB budget,” Theron explains. “Hence, DR-TB has a destabilising effect on the healthcare system. Patients with DR-TB also have a very poor outcome. What’s more, we’ve noticed recently that most cases of DR-TB have begun to be caused by person-to-person transmission, rather than the typical trend of patients developing DR-TB internally, caused by not adhering to their medication regime, for example. 

“There is hence a critical mass of infectious DR-TB patients. Interestingly, there is a spectrum of infectiousness, and there is a minority of ‘super-spreading’ patients who, despite comprising only about 20% of patients, are thought to be responsible for 80% of transmission. Identifying the determinants of super-spreading in DR-TB is a big focus of my current studies. This could, for example, permit super-spreaders to be diagnosed and triaged for targeted infection control interventions.” 

Theron is not only leading the way with his research and findings — as evidenced by more than 15 academic and civil society awards, participation in more than 15 lectures or panel discussions, and his participation in more than 50 published academic works in various forms — he plays a leading role in nurturing the research talent of the future while encouraging greater depth in research around TB. He has supervised research students from BSc to post-doctoral level since 2006.

“Publishing and promoting scientific progress is a big inspiration for me, as is supervising and mentoring research studies,” he says. “My biggest challenges by far are university-related admin and bureaucracy, and raising funds for research.” 

He believes that his greatest achievement so far is his and his team’s multi-centre study on the GeneXpert test, published in The Lancet, and receiving the Young Investigator Award from the International Union Against Tuberculosis and Lung Disease.