What is multidrug-resistant tuberculosis and how do we control it?

Q: What is multidrug-resistant tuberculosis and how do we control it?

A: The bacteria that cause tuberculosis (TB) can develop resistance to the antimicrobial drugs used to cure the disease. Multidrug-resistant tuberculosis (MDR-TB) is TB that does not respond to at least isoniazid and rifampicin, the two most powerful antituberculosis drugs. Every year, more MDR-TB cases are being reported.

The primary cause of multidrug resistance is mismanagement of TB treatment. Most people with tuberculosis are cured by a strictly followed, six-month drug regimen that is provided to patients with support and supervision. Inappropriate or incorrect use of antimicrobial drugs, or use of ineffective formulations of drugs, can cause drug resistance. Strong and enforced regulations to ensure acceptable, effective tuberculosis treatment can help control MDR-TB.

In some countries, it is becoming increasingly difficult to treat MDR-TB. Treatment options are limited and recommended medicines are not always available. In some cases even more drug-resistant tuberculosis is developing. Extensively drug-resistant TB, XDR-TB, is a form of multi-drug resistant tuberculosis that responds to even fewer available medicines.

There were about 630 000 cases of MDR-TB present in the world in 2011. It is estimated that about 9% of these cases were XDR-TB.