Wednesday, August 15, 2012

TB Test Produces Better Results

 The U.S. President’s Emergency Plan for AIDS Relief (PEPFAR), USAID, UNITAID, and the Bill & Melinda Gates Foundation are partnering to significantly reduce the cost of a new highly accurate rapid diagnostic test for TB in 145 high-burden and developing countries.

Funds provided by this partnership will reduce the cost of Xpert MTB/RIF cartridges from $16.86 to $9.98 a price which won’t increase until 2022. To date, the high unit cost of the cartridges produced by the medical device manufacturer Cepheid has proven to be a barrier for the widespread use of the diagnostic TB test in low and middle income countries.

Until Cepheid developed the cartridge, the only method used in most developing countries laboratories was smear microscopy which is particularly insensitive for diagnosing TB in patients who are co-infected with HIV and does not help clinicians detect drug-resistant strains of TB.

The capacity of the Xpert MTB/RIF assay to yield a rapid and accurate diagnosis has the potential to improve TB diagnosis and treatment in rural clinical settings. A large percentage of people with TB fail to start treatment promptly because of the long wait for results from older conventional tests and they also may need to return to the clinic that may be far from where they live.

Cepherd’s GeneXpert is a molecular diagnostic system that can detect TB in patients co-infected with HIV and resistant to the antibiotic rifampicin and produce the results in less than two hours. Patients are able to start immediately on an on appropriate treatment, including second-line drugs in cases of drug resistance.

Research suggests that the incremental scale up of GeneXpert in countries with high TB burdens could enable the rapid diagnosis of 700,000 cases of TB and save health systems in low and middle income countries more than $18 million in direct health costs.