A study published today in The New England Journal of Medicine provides compelling evidence that extensively drug-resistant tuberculosis (XDR TB) is spread from person-to-person in the KwaZulu-Natal province, South Africa from 2011–2014. The study was conducted by a team of researchers from Emory University, the U.S. Centers for Disease Control and Prevention, Albert Einstein College of Medicine, and the University of KwaZulu-Natal in South Africa and was funded by the U.S. National Institute of Allergy and Infectious Diseases at the National Institutes of Health. It builds on a growing body of evidence showing that person-to-person transmission, not just inadequate treatment, is driving the spread of drug-resistant TB.
South Africa is experiencing a widespread epidemic of XDR TB, the deadliest form of TB, including a tenfold increase in cases between 2002 and 2015. The study found that the majority of cases (69 percent) in high HIV- and high TB-burden areas happened due to person-to-person transmission rather than inadequate TB treatment in South Africa. By using social networks analysis, the study identified numerous opportunities for transmission not only in hospitals, but also in community settings, such as households and workplaces.The study has important implications for efforts to prevent drug-resistant TB, which have traditionally focused on ensuring that patients receive accurate and complete TB treatment.
“These findings provide insight as to why this epidemic continues despite interventions to improve TB treatment over the past decade. Public health and research efforts must focus more intensely on identifying and implementing additional or new interventions that halt transmission in hospitals and community settings.” said Emory University’s Dr. Neel R. Gandhi.
The study included 404 XDR TB patients in KwaZulu-Natal, South Africa and was led by a team of researchers including Dr. Neel R. Gandhi, of Emory University and Dr. Sarita Shah, of CDC’s Division of Global HIV & TB. Researchers examined the role of transmission by combining robust genotyping methods with social network and epidemiologic analysis. The study is the first of its kind, bringing together these multiple state-of-the-art methods to study XDR TB transmission in a high-incidence setting.
“These findings are further proof that we need to better detect, prevent, diagnose, and treat drug-resistant TB,” said CDC director Dr. Tom Frieden. “TB resistant to last-resort drugs is spreading through hospitals and homes, at work, and in other places in this high burden community. The only way to stop this disease is by improving infection control and rapidly finding and effectively treating people with TB.”