Issues We Face

Drug Resistant Tuberculosis

How does drug-resistant TB develop and spread?

An airborne disease, TB is spread through coughing, sneezing or simply talking. The risk of transmission increases where there is a high concentration of TB bacteria – in overcrowded and poorly ventilated settings where people congregate, including houses, hospitals, waiting rooms, offices and prisons. People with compromised immune systems – such HIV – are at very high risk of contracting and developing TB disease.

TB can usually be treated with a standard course of four first-line, anti-TB drugs. If these drugs are misused or mismanaged, multidrug-resistant TB or MDR-TB can develop. MDR-TB takes longer to treat with second-line drugs (usually two years), which are more expensive and have more toxic side effects.

XDR-TB can develop when these second-line drugs for MDR-TB treatment are also misused or mismanaged. With XDR-TB, the most powerful first-line and second-line TB medications are no longer effective, severely limiting the chance of treatment success and cure for these patients.

Drug-Resistant TB in South Africa

With 18 percent of its adult population infected with HIV in 2009, South Africa is home to one of the world’s worst HIV epidemics and one of the highest burdens of TB. Despite an advanced public health system and far greater capacity for TB drug resistance surveillance than any other sub-Saharan country, the HIV epidemic has overwhelmed and disrupted an already faltering TB control program. This has led to increases in TB treatment failure and default and greater opportunities for drug-resistant TB to emerge and spread among HIV-infected and uninfected people.

HIV and drug-resistant TB co-infection

The convergence of TB, HIV and XDR-TB has created a new and dangerous major epidemic in South Africa. The number of cases of both XDR-TB and MDR-TB has continued to increase. XDR-TB is now present in all nine South African provinces and its neighboring countries and has been reported in nearly 60 countries worldwide. The largest number of cases remains in the Tugela Ferry area with over 500 cases reported as of December 2009. In addition, many more cases have been suspected but not diagnosed, due in part to delays in patients presenting for medical care and limitations in diagnostic tests for TB.

In addition to the dangers to individual patients, their spread could derail recent advances in TB control and HIV treatment, especially in areas of sub-Saharan Africa, like Tugela Ferry, with high HIV infection rates. Scientific predictions indicate that the number of cases will continue to escalate upwards if a comprehensive and coordinated response, directed at both drug-resistant TB and HIV, is not rapidly implemented.