They warn that new variations of the disease now defeat many of the world's existing drugs and "the forced isolation and confinement of XDR-TB (extensively drug resistant tuberculosis) and MDR-TB (multiple drug resistant tuberculosis) infected individuals may be a proportionate response in defined situations given the extreme risk posed."Â
Writing in the peer-reviewed online journal PLoS Medicine, co-authors Ross Upshur, MD, Director of the University of Toronto Joint Centre for Bioethics, and South Africa-based HIV-AIDS experts Jerome Amir Singh and Nesri Padayatchi, MD, say the world community urgently needs to help isolate and contain the threat.
"The South African government's initial lethargic reaction to the crisis and uncertainty amongst South African health professionals concerning the ethical, social and human rights implications of effectively tackling this outbreak highlights the need to address these issues as a matter of urgency lest doubt and inaction spawns a full-blown XDR-TB epidemic in South Africa and beyond,"Â the paper says.
The World Health Organization (WHO) announced Sept. 1, 2006 that yet another deadly new strain of extensively drug resistant tuberculosis (XDR-TB) had been detected in Tugela Ferry, a rural town in KwaZulu-Natal (KZN) province, epicenter of South Africa's HIV / AIDS epidemic. Eight days later, the WHO urged a response to the outbreak akin to recent global efforts to control SARS and bird flu.
The new strain in September appeared within a year of a study showing 221 of 544 TB patients in KNZ province had multi-drug resistant tuberculosis (unresponsive, at a minimum, to front-line drugs rifampicin and isoniazid). Among the 221 cases, 53 were extensively drug resistant - i.e. resistant to rifampicin and isoniazid and to three or more of the six potential second line drug options.
Of the 53 XDR-TB patients, 44 were tested for HIV; all were infected with that disease too. The median survival from the time of sputum specimen collection was just 16 days for 52 of the 53 infected individuals, including six health workers and those reportedly taking anti-retroviral drugs.
"Such a fatality rate for XDR-TB, especially within such a relatively short period of time, is unprecedented anywhere in the world,"Â the authors warn.
They note that South Africa is among the world's fastest growing tourist destinations, home to millions of migrant labourers, with ports and roads servicing several African countries.
"Cumulatively, these factors make for a potentially explosive international health crisis. The threat to regional and global public health is thus clear and further underlined by reports that XDR-TB is now considered endemic to KZN "Â¦ reported in at least 39 hospitals throughout the province and in other parts of the country."Â
South African XDR-TB cases numbered 300 on Dec. 1, 2006 and at least 30 new cases of XDR-TB are now reportedly detected each month in KZN alone, according to the paper.
XDR-TB diagnoses to date (which require specialized laboratory facilities) "likely represent a small proportion of the true extent of the problem. The number of persons harbouring latent infections is unknown (and likely unknowable at present),"Â they add. - University of Toronto Joint Center for Bioethics