By Nicole Swartwood
A new study was published this week suggests that the epidemic of extensively drug-resistant tuberculosis (XDR-TB) is spreading in a high TB area of South Africa through person to person transmission.
XDR-TB is a rare form of tuberculosis that is resistant to treatment with at least four of the most common TB treatment drugs. It has been previously thought that XDR-TB epidemics were caused by the mistreatment of multi-drug resistant tuberculosis (MDR-TB). Management of MDR-TB is a long, complex, multi-actor system that relies on a good relationship between the patient, the provider, and often a community volunteer. Providing proper care is so involved, that the World Health Organization (WHO) has published a 62 page guide on the subject. Current thought is, when MDR-TB treatment fails, due to poor drug reactions or patient adherence, the risk of developing XDR-TB is high.
In contrast, the study, led by Dr. Sarita Shah, found that nearly two-thirds of new XDR-TB in South Africa’s KwaZulu-Natal Province, were from person-to-person transmission, rather than failed treatment of MDR-TB. The paper used genotypic analysis, in which the bacteria in a patient can be analyses for genetic similarities to samples in other patients. The results, which can link those with TB of similar genetic makeups, point to a “complex web of interconnectedness” among cases in community and healthcare settings.
The paper is turning heads in the world of tuberculosis management and several news outlets have been covering the impact. In an interview with NPR, Dr. Shah called for a renewed focus on controlling tuberculosis early and preventing airborne transmission, specifically in health-care settings. While diagnosing early is key, Shah suggests a focus on environmental changes through new technologies, such as ultra-violet lights to kill the bacteria or increased ventilation to prohibit high concentrations. This study opens a new opportunity for Public Health specialists, clinicians, and engineers to collaborate to reduce the transmission of XDR-TB.