The Underestimated Pandemic

5 October 2011, 08:24


More than one third of the world’s population is infected by tuberculosis (TB), and Africa is responsible for 30 percent of reported TB cases. If left untreated, infected persons can spread the disease to 10-15 people per year according to the World Health Organisation (WHO). Existing treatments for TB are much less effective against new drug-resistant TB infections, which are being identified at an alarmingly high, and increasing, rate. As research on the disease continues, scientists acknowledge that they currently do not know enough about TB.

The Institute of Medicine (IOM) of the United States National Academy of Sciences and the Academy of Science of South Africa (ASSAf) recently released their proceedings report of a Workshop on  The Emerging Threat of Drug-Resistant Tuberculosis in Southern Africa: Global and Local Challenges and Solutions at UKZN’s Nelson R Mandela School of Medicine.

Dr Gail Cassell from IOM and Professor Roseanne Diab of ASSAf invited experts in the field of Drug-Resistant TB to present on different aspects of TB and hold a panel discussion on the solutions and advice for policy makers. The event was associated with the groundbreaking ceremony for the new KwaZulu-Natal Research Institute for Tuberculosis and HIV (K-RITH),a collaboration between the Howard Hughes Medical Institute and UKZN.

The IOM/ASSAf report reflected the perspectives of a number of workshop participants that Multi, Extensively, and Totally Drug Resistant Tuberculosis (MDR-/XDR-/TDR-TB) are largely underestimated. A number of workshop participants also noted that the vast majority of MDR and XDR-TB cases are undetected and thus untreated with appropriate second-line drugs. TB transmission from person to person is a key challenge in South Africa.

Professor Paul van Helden, Director of The Centre of Excellence for Biomedical TB Research, noted that using WHO estimates, 80 percent of MDR-TB cases are due to transmission.

Cassell said that there is a silent pandemic of MDR-TB infections in children, and that infection control should be a key focus in current research. She added that there is a high emergence of TDR-TB locally and globally, increasing the number of dangerous and untreatable infections daily.

Van Helden noted that Ethambutol (the most common second-line drug for MDR/XDR-TB) is only 50 percent effective in treating patients in South Africa.  He added that more than a quarter of TB infections in the Eastern Cape are XDR-TB, and questioned whether South Africa should look into patient isolation to prevent new transmission in the area. Cassell noted that research supposes that patients with drug-resistant TB might have to take three different antibiotics at the same time to treat the disease. She described this as financially and physically challenging for patients.

Dr Gary Reubenson from the Department of Paediatrics and Child Health at the Rahima Moosa Mother and Child Hospital specialises in paediatric cases of drug-resistant TB in South Africa. He noted that paediatric TB is not a priority around the world and that information about it is limited, but that the Western Cape has conducted most of the research available.

Currently 19 percent of paediatric TB is MDR-TB, but scientists are sure that there are many more missed cases of the disease. ‘Most MDR-TB treatments are not child friendly or are not effective, but fortunately, children are more tolerant to treatment than adults. The major challenge in child cases is managing infection control at home, in hospitals and at clinics,’ Reubenson said.

Dr Bruce Margot from the KwaZulu-Natal Department of Health presented on the province’s programmes to assist TB patients and increase awareness of the disease. His presentation emphasised the promise of new public health approaches for addressing the disease. “The Department decentralised its structure in order to deal with TB and MDR-TB prevention, infection, and treatment efficiently. This move was very effective and brought positive changes. We engaged in many programmes in order to deal with the pandemic and our results report a decline in TB infections, regardless of the high HIV infections,” Margot said.