Extreme drug resistant tuberculosis (XDR-TB) or also known as extensive drug-resistant tuberculosis is multi drug-resistant tuberculosis (MDR-TB) that is resistant to three or more of the six classes of second-line drugs use for the treatment of tuberculosis. XDR-TB received widespread media attention in 2008 when a number of cases were reported in KwaZulu Natal (KZN), South Africa. This was due to a study in The Lancet that brought to light the outbreak of the highly virulent XDR-TB in KZN, South Africa.
XDR-TB poses grave health concerns especially in areas with limited health care resources and prevalent HIV infection. It often develops when second line TB drugs are mismanaged or misused, often due to the ignorance of the TB patient, and renders these drugs ineffective. The prevalence in Kwazulu Natal could be due to the difficulty for TB patients to reach state hospitals especially in the rural areas. This often leads to compliance issues where the patient starts and stops treatment over a period of time due to ignorance, distance from health facilities and difficulty in acquiring the necessary advice and treatment due to backlogs in state hospitals.
The problem of XDR-TB is not unique to South Africa. In the United States, at least 4% of tuberculosis cases were identified as XDR-TB and 19% of MDR-TB cases in Latvia met the criteria for XDR-TB. Treatment options are seriously limited due to the resistance of this tuberculosis strain to conventional drugs. The World Health Organisation (WHO) has identified the need for pharmaceutical companies to work with regulatory agencies and governments in order to develop a new range of drugs for use against XDR-TB. This process needs to be fast tracked as the potential spread of XDR-TB could affect nations across the globe. It is hoped that pharmaceutical companies, who often have better resources than state institutions, can quickly develop suitable drugs without being restricted by corporate earnings and investment to assist governments with necessary drugs for “compassionate use”.
There is some glimmer of hope in treating XDR-TB according to the Global Alliance for TB Drug Development. Recent efforts by South African state facilities has shown that if XDR-TB is identified early and patients isolated with suitable treatment in proper facilities, the spread of XDR-TB can be limited and patients may be able to recover. However one of the biggest obstacles in the fight against XDR-TB in South African is the prevalence of HIV/AIDS.