Tuberculosis kills more people than any other pathogenic illness

IN 1882, WHEN Robert Koch discovered Mycobacterium tuberculosis, the microbe that causes tuberculosis, the disease caused one in seven deaths in America and Europe. Transmitted through droplets from coughs, sneezes or just talking, tuberculosis felled rich and poor alike. In the century that followed, TB (as the illness is called for short) beat a retreat thanks to antibiotics and a vaccine that protected infants. By the 1990s wiping it out completely seemed tantalisingly within reach.

Since then, however, progress has been glacial. New cases are falling by just 1-2% a year. Today, M. tuberculosis kills more people than any other single pathogen (see chart). The World Health Organisation (WHO) estimates that 10m people fall ill with it each year and 1.5m die. This is more than three times the number of those who succumb to malaria. A recent wave of scientific breakthroughs is, though, starting to bear fruit, and there is now widespread optimism that things will change dramatically over the next decade. “It is the first year in which we have some hope,” says Lucica Ditiu, head of the Stop TB Partnership, a global alliance of antituberculosis organisations.