A predictive blood test for tuberculosis may soon become a reality thanks to the research efforts from scientists.
A DNA fingerprint in the blood could identify which carriers of TB will go on to get symptoms and spread the infection.
The test could mean earlier diagnosis and treatment of the lung disease, potentially saving many lives.
Current skin or blood tests can only show if someone is harbouring TB, but not showing symptoms. But it is impossible to predict who will get the full-blown disease.
Tuberculosis, or TB, is an infectious bacterial disease of the lungs, causing symptoms such as coughing, chest pains and weight loss.
Researchers from the UK, US and South Africa found same genetic markers in the blood of 10percent of patients with active TB.
"If you could predict which so-called carriers of TB will progress to the full-blown disease, this would have major ramifications for stopping the global epidemic," the BBC quoted Lead researcher Dr Anne O'Garra as saying.
"A new diagnostic technique based on a blood test may be particularly important in HIV positive patients with TB where the usual technique of diagnosis from sputum is often unhelpful," said Mike Mandelbaum, chief executive of the charity TB Alert.
O'Garra added that the blood test showed promise but needed further work.