A team at the University of Cape Town (UCT) have developed a test to rapidly and accurately diagnose TB meningitis, a fast acting and difficult to detect infection occurring in some cases of TB.

With an estimated 80% of the population infected with the bacteria, TB is a leading cause of death in South Africa. While progress has been made in addressing and treating TB, identifying and treating TB meningitis has not had the same success. TB meningitis develops as an infection of the membranes around the central nervous system in close to 2% of TB cases, with a high risk of death or disability if not treated.

The test, developed with partners Antrum Biotech and currently under evaluation for the international market, seeks to replace three testing methods currently available which the team said are are not accurate enough and have serious drawbacks.

Smear microscopy only works 5% of the time while growing the bug in a culture has a sensitivity of up to 70% but can take four to eight weeks to give a result. By that time most people would have died, or developed severe disabilities due to the disease. The GeneXpert DNA detection test for TB is widely used in South Africa, but studies show that it is not sensitive enough to detect TB meningitis.

“Although it [the GeneXpert DNA detection test] is rapid in getting the answer on the same day, it detects TB meningitis in only 50% to 60% of cases. Preliminary results from our studies show a vast improvement in sensitivity when compared to GeneXpert,” said Professor Keertan Dheda, the director of the Centre for Lung Infection and Immunity at UCT.

Antrum Biotech chief executive Khilona Radia said the accurate diagnosis of TB meningitis represented an unmet need in public health, with problems of missed diagnosis and misdiagnosis affecting health outcomes.

“The greatest need for the test is in populations with a high burden of TB and HIV; particularly in sub-Saharan Africa. TB meningitis can cause death or disability, especially in children, but is easily treatable if diagnosed early,” Radia said. – Read the full article on the IOL website.