TB resurgence poses grave threat worldwide: Researchers

London: Medical charity Medecins Sans Frontieres has warned that the rise of new strains of TB which are resistant to drugs pose grave threat worldwide.

The charity said that the efforts to fight multidrug-resistant TB (MDR-TB) have been "inadequate" and they have called for an "immediate international response" to find new treatments, the Independent reported.

Despite continuous efforts TB still kills about 1.3 million people every year.

The new strains that are resistant to antibiotics are much harder to treat, and now nearly 500,000 cases of MDR-TB occur each year.