tb cells

y relying on blood samples, the new technique, if it passes the litmus test, would be able to side-step the inherent drawbacks of sputum samples and correctly diagnose more children with TB disease.

With bacteriological diagnosis of TB (via sputum samples) in children, particularly in those aged below five years, being riddled with problems, scientists are looking at alternative methods that do not rely on sputum samples. A proof-of-concept study published recently in The New England Journal of Medicine shows promise. The sample used was blood.

Suzanne T. Anderson from the Brighton and Sussex Medical School, University of Sussex and others could confirm TB disease by looking for specific signatures in 51 genes. And the presence of these signatures in 42 genes could help distinguishing TB disease from latent TB. The signatures in question were RNA transcripts.

To test the robustness of the signatures in correctly diagnosing TB disease and differentiating latent TB from TB disease, the scientists had a discovery cohort (where TB was suspected) comprising of 655 South African and 701 Malawian children. A validation cohort (children with one or more typical clinical symptoms and were household contacts of people with smear positive pulmonary TB disease) comprised 1,599 Kenyan children.