UCT PhD graduate Ryan Dinkele has revealed that normal breathing is a major contributor to TB spread.
A recent study by a University of Cape Town PhD graduate has revealed that new evidence suggests that breathing alone is estimated to contribute over 90% of the daily mycobacterium tuberculosis bioaerosol output among patients with active TB.
Ryan Dinkele, who graduated on Thursday with a PhD in medical microbiology, said before the Covid-19 pandemic, TB was the leading cause of death globally, owing to a signal infectious agent.
His study was titled: Catching a glimpse: the visualisation of mycobacterium tuberculosis from TB patient bioaerosols.
TB claimed 1.5 million lives in 2020 and, unlike Covid-19, it remains out of the global spotlight and predominantly impacts young adults and disproportionately affects the poor. The inability of antibiotics and the TB vaccine (Bacille Calmette-Guérin) to eradicate the TB epidemic necessitated further research into how, when, and by whom mycobacterium tuberculosis was spread.
Dinkele said the study was conducted in two parts with the central aim of advancing the understanding of how mycobacterium TB was aerosolised. He said he also collected bioaerosol samples from 30 TB patients using Respiratory Aerosol Sampling Chamber (RASC), a custom-made personal clean room built to catch bioaerosols, the droplets and particulate matter that become aerosolised during respiration.
He said it had long been assumed that TB was spread through coughing, but new findings had shown that it may also be spread through normal breathing.
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“The first objective was to develop a novel method for the microscopic detection of mycobacterium TB bacilli in bioaerosol samples. Once this was developed, I collected bioaerosol samples from 30 TB patients using RASC. I found that the sensitivity of this method was high, which was striking as the participants were sampled for 60 minutes without any requirement for forced coughing,” he said.
Dinkele added this observation led to the second component of his work, which was to test the longstanding assumption that coughing was the primary driver of the mycobacterium TB transmission.
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“For this question, I altered the RASC to allow for the direct comparison of breathing, deep breathing and coughing. The mycobacterium TB detection methodology was then applied to independently examine the bioaerosol from each of the samples. This work forced us to challenge longstanding assumptions that are currently accepted in TB research.”
