NextBillion - An Initiative of the William Davidson Institute at the University of Michigan

Friday, June 6, 2014

NAIROBI/KISUMU, 5 June 2014 (IRIN) – Accurate diagnosis of tuberculosis among children is notoriously difficult because the bacteria causing the disease tend to be detectable in the sputum only of adults, and because the clinical symptoms used to diagnose TB in children are also present in other conditions.

This leads to false positives and consequent inappropriate treatment and increased drug resistance; and to false negatives, which means a correct diagnosis is only possible when it’s too late, after the disease may have spread from the lungs to the brain, or other organs.

In many poor countries, health staff using a standard test fail to detect TB in children up to 93 percent of the time, according to medical charity Médecins Sans Frontières.

According to new research – published in the New England Journal of Medicine – involving 2,800 children hospitalized in South Africa, Malawi and Kenya, the key to better TB diagnosis could lie in 51 genes found in the blood of infected children.

During the seven-year study, researchers determined which of these genes were activated and suppressed among infected children. Using this information to develop a “TB risk score”, the method was found to be accurate in more than 80 percent of cases.

The hope is that the discovery of such a “signature” will lead to a cheap and effective test for childhood TB.