Multidrug-resistant tuberculosis (MDR-TB) October 2013 Update

WHO October 2013 (GTB number C7) For more information: www.who.int/tb/challenges/mdr

Detection of MDR-TB cases (red line) and additional rifampicin-resistant TB (RR-TB) cases (blue) compared with TB cases enrolled on MDR-TB treatment (green), trends

between 2009 and 2012 in the 27 high MDR-TB burden countries and globally

Key findings:

Drug-resistance among TB cases: about 3.6% of new tuberculosis (TB) patients in the world have multidrug-resistant strains (MDR-TB). Levels are much higher about 20% - in those previously treated for TB. The frequency of MDR-TB varies substantially between countries. About 10% of MDR-TB cases are also resistant to the two most important second-line drug classes, or extensively drug-resistant TB (XDR-TB). By September 2013, 92 countries had reported at least one XDR-TB case.

MDR-TB case-load and deaths: WHO estimates that there were about 450,000 new (incident) MDR-TB cases in the world in 2012. More than one half of these cases occurred in China, India, and the Russian Federation. About 170,000 MDR-TB deaths are estimated to have occurred in 2012.

Detection of MDR-TB patients: is increasing. Almost 84,000 patients with MDR-TB were notified to WHO globally in 2012, up from 62,000 in 2011. The biggest increases were in India, South Africa and Ukraine. Only about 9% of retreatment TB cases had DST results reported although the proportion was much higher in certain high burden countries.

Enrolments on MDR-TB treatment in 2012: were equivalent to one in four of the MDR-TB cases estimated to occur among pulmonary TB patients notified in the world. The ratio of enrolments to MDR-TB cases detected was about 92% but varied widely by country (upper graphic).

Treatment success: 48% of patients with MDR-TB enrolled on treatment in 2010 were reported to have been successfully treated (lower graphic). More patients have been monitored for outcomes over time but the proportion without outcome data remains high.

Treatment outcomes for MDR-TB patients started on treatment globally, 2007-2010. The number of MDR-TB cases monitored shown beside each bar.

www.who.int/tb/

FUNDING FOR MDR-TB

In 2009, the World Health Assembly urged WHO Member States

"to achieve universal access to diagnosis and treatment of MDR-TB and XDR-TB by 2015

WHAT ARE MDR-TB, XDR-TB AND RR-TB ?

TB organisms resistant to the antibiotics used in its treatment are widespread and occur in all countries surveyed. Drug resistance emerges as a result of inadequate treatment and once TB organisms acquire resistance they can spread from person to person in the same way as drug-sensitive TB.

Multidrug-resistant TB (MDR-TB) is caused by organisms that are resistant to at least the two most effective anti-TB drugs, isoniazid and rifampicin.

Extensively drug-resistant TB (XDR-TB) is a form of TB caused by organisms that are resistant to isoniazid and rifampicin (i.e. MDR-TB) as well as any fluoroquinolone and any of the secondline anti-TB injectable drugs (amikacin, kanamycin or capreomycin).

Rifampicin-resistant TB (RR-TB) is caused by organisms that are resistant to rifampicin, with or without resistance to other drugs. Both MDR-TB and XDR-TB are forms of RR-TB.

These forms of TB do not respond to the standard six month treatment with first-line anti-TB drugs and can take two years or more to treat with drugs that are less effective, more toxic and more expensive.

In 2015, it is estimated that about 20% of the USD 8 billion that low- and middle-income countries require for TB care and control will be needed for the treatment of MDR-TB. In 2013, funding available for MDR-TB is expected to reach USD 1 billion in countries reporting data. Costs for second-line drugs alone amount to USD 0.4 billion in 2013. The countries with the greatest amount of funding available for MDR-TB in 2013 were India, Kazakhstan, the Russian Federation, South Africa, and Ukraine.

THE GLOBAL RESPONSE TO MDR-TB AND XDR-TB

Enrolment on MDR-TB treatment (blue squares, 20092012), compared with the targets in the Global Plan to Stop TB, 20112015 (green line) and projections provided by countries (green circles)

The Global Plan to Stop TB, 2011-2015 envisages that in order to progress towards universal access, about one million MDR-TB patients need to be placed on treatment between 2011 and 2015. The Plan also aims to have at least 75% of MDR-TB patients completing their treatment successfully by 2015. In 2012, about 45% of cases targeted to be placed on treatment globally that year were reported to have been enrolled. Among MDR cases starting treatment in 2010, the 75% treatment success threshold was achieved by 34 of the 107 countries reporting outcomes.

WHO October 2013 (GTB number C7) For more information: www.who.int/tb/challenges/mdr