Untreatable Tuberculosis Spreading in South Africa

Researchers at the University of Cape Town (UCT; South Africa), Stellenbosch University (Tygerberg, South Africa), and other institutions prospectively followed a cohort of 107 patients from three provinces in South Africa between March 2008 and August 2012 who had been diagnosed with extensively drug-resistant (XDR) TB. Available isolates from 56 patients were genotyped to establish strain type and used for extended susceptibility testing; 44 patients (41%) had HIV, and 36 (64%) of the 56 isolates were resistant to at least eight drugs, with resistance to an increasing number of drugs was associated with the Beijing genotype.

The results showed that after 24 months of follow-up, 17 patients (16%) had a favorable outcome, 49 (46%) had died, seven (7%) had defaulted (interruption of treatment), and 25 (23%) had failed treatment. At 60 months, 12 patients (11%) had a favorable outcome, 78 (73%) had died, four (4%) had defaulted, and 11 (10%) had failed treatment. In all, 45 of the patients were discharged from hospital; 42% of these patients failed antituberculosis treatment and were TB culture positive, even though they had a minimum of 12 months treatment.

Of these patients, one-third were deemed at high risk for transmitting the disease, and the researchers found that these patients survived in the community for an average of 20 months, a lengthy time period during which they could infect others. By using DNA finger printing, the researchers were able to confirm that one XDR-TB patient, who had failed treatment and was discharged into the community, transmitted the infection to his brother, who eventually passed away. The study was published early online on January 17, 2014, in the Lancet.

“In South Africa, long-term outcomes in patients with XDR tuberculosis are poor, irrespective of HIV status. Because appropriate long-stay or palliative care facilities are scarce, substantial numbers of patients with XDR tuberculosis who have failed treatment and have positive sputum cultures are being discharged from hospital and are likely to transmit disease into the wider community,” concluded senior author Prof. Keertan Dheda, MD, of the UCT department of medicine, and colleagues. “Testing of new combined regimens is needed urgently and policy makers should implement interventions to minimize disease spread by patients who fail treatment.”

TB is an infectious disease caused by the bacteria Mycobacterium tuberculosis. The disease primarily affects the lungs, but it can also affect other organs. Typical symptoms include persistent coughing (in which a person can bring up blood), weight loss, night sweats, fever, tiredness and fatigue, and loss of appetite. TB is one of the most deadly diseases in the world, since the bacteria can easily spread from person to person through airborne particles; in addition, XDR and totally resistant TB types are becoming increasingly more common.

Related Links:
University of Cape Town
Stellenbosch University