Tuberculosis (TB) is a disease caused by a bacterial infection which is transmitted through the air when someone who is infectious with the disease coughs or sneezes. TB is both preventable and treatable with special antibiotics, yet every year it kills more people than any other infectious disease. In fact, in each year more people are currently dying from TB than HIV and malaria combined.

Treating this disease is complicated by the fact that the mycobacteria possess an unusually thick, waxy cell wall which isn’t easy for drugs to penetrate - but also because they have the ability to survive in multiple locations in the body. An initial infection, furthermore, has the unusual capacity to ‘hide out’ in the body, potentially for years following the first infection – a condition which is called ‘latent infection’.

​

Because these bacteria are so hardy it means that even straightforward treatment of ‘drug-susceptible’ TB needs a combination of four different drugs taken for at least six months. With drug-resistant forms it currently needs six weaker and more toxic drugs taken for between 9 and 24 months. These drugs can have pernicious and often permanent side-effects and are associated with very poor treatment outcomes. Unfortunately these treatments are also currently largely unaffordable in the countries which most need them.