One of the best known superbugs, MRSA, is alone estimated to kill around 19,000 people every year in the United States - far more than HIV and AIDS - and a similar number in Europe.
And others are spreading. Cases of totally drug resistant tuberculosis have appeared in recent years and a new wave of "super superbugs" with a mutation called NDM 1, which first emerged in India, has now turned up all over the world, from Britain to New Zealand.
Last year the WHO said untreatable superbug strains of gonorrhoea were spreading across the world.
Antibiotic Resistance Poses 'Catastrophic Threat' To Medicine, Says Britain's Top Health Official