Predictive blood test for TB 'a step closer'

International researchers say they have made a "significant step" towards a predictive blood test for tuberculosis.

A DNA fingerprint in the blood shows promise in identifying which carriers of TB will go on to get symptoms and spread the infection.

Such a test would allow earlier diagnosis and treatment of the lung disease, potentially saving many lives.

Experts say the research, published in Nature, is "remarkable" but needs to be proven by further work.

Tuberculosis, or TB, is an infectious bacterial disease of the lungs, causing symptoms such as coughing, chest pains and weight loss.

Someone in the world is newly infected with TB every second, with nearly two million deaths each year.