Tuberculosis (TB) is the world’s biggest infectious disease killer with multidrug-resistant TB (MDR-TB) posing a particular threat to global health. A study led by the Swiss Tropical and Public Health Institute (Swiss TPH) shows that resistance to the new MDR-TB treatment regimen recently recommended by the World Health Organization is already spreading between patients. The findings, published yesterday in the renowned New England Journal of Medicine, highlight the urgent need for better surveillance and infection control to counteract the rise in antimicrobial resistance.