The re-emergence of polio in the UK is just the latest troubling sign that the world is headed for a "perfect storm" of new and existing viruses raging through the population.
We're living through a "new pandemic era" according to experts, who say the next 'Disease X' could be just around the corner.
Disease X is a placeholder name adopted by the World Health Organisation three years ago, representing a hypothetical, as-yet unknown pathogen that could cause a future epidemic.
