In a recent study published in the Proceedings of the National Academy of Sciences (PNAS), researchers from the University of Cape Town and Amsterdam UMC revealed shocking revelations about the transmission of Mycobacterium tuberculosis (Mtb). Mtb is the bacteria responsible for tuberculosis.
The study found that Mtb is present in the exhaled breath of 90% of individuals presenting with suspected tuberculosis, even those who tested negative on conventional sputum tests. This raises concerns about potential undetected transmission.Â
The research focused on more than 100 patients seeking medical attention in clinics across South Africa. The study used a novel method of aerosol sampling in a community-based dedicated TB aerobiology lab.
The results showed that 90% of patients, including those who had initially tested negative for tuberculosis through sputum testing, carried Mtb in their exhaled breath. This challenges the existing paradigm that only individuals with diagnosed tuberculosis expel the bacteria, suggesting a much broader range of potential transmitters than previously recognized.Â
Ben Patterson, an external Ph.D. student at Amsterdam UMC and the Amsterdam Institute for Global Health and Development, emphasized the implications of the findings for public health interventions. “If someone carries Mtb in their respiratory tract, this may also mean they can spread it.
Therefore, since these results suggest a much broader range of people transmitting TB than previously recognized, there are significant implications for public health interventions designed to interrupt transmission.”Â
During this research, participant patients were followed over six months, and aerosol samples were repeatedly collected at three separate time points. It showed that the presence of Mtb decreased in those undergoing treatment and in those not on treatment.
However, the study revealed that 20% of participants continued to test positively for Mtb in aerosol after six months, challenging the previous understanding of the duration of transmission.Â
Frank Cobelens, professor of Global Health at Amsterdam UMC and senior fellow at the AIGHD, commented on the complexity of tuberculosis and the implications for public health practices.
“Together, our results indicate how complex tuberculosis is and perhaps also why it is so difficult to eliminate tuberculosis in endemic areas. Even when public health agencies work, according to the current guidelines, effectively against symptomatic TB cases. In this sense, a revaluation of our practices is necessary.”Â
The study results challenge existing perceptions about tuberculosis transmission and underscore the need for a comprehensive re-evaluation of public health strategies to combat the spread of this infectious disease.
The possibility of undiagnosed individuals transmitting Mtb highlights the complexity of tuberculosis and emphasizes the urgency for more effective interventions to curb its transmission in endemic regions.Â
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