Drug-resistant tuberculosis is a major public-health problem in poor nations. While antibiotics can effectively treat TB, they cause nausea and other side effects, and many patients stop taking them a month or two into the six-month treatment regimen. That can foster drug-resistant forms of the infection, which are deadlier and more expensive to treat.
A new monitoring system that combines cheap, paper-based diagnostics with text-messaging technology could help health organizations, with the coöperation of telecommunications companies, give patients another incentive to adhere to the drug regimen. José Gómez-Márquez, program director for the Innovations in International Health program at MIT, and his collaborators developed a simple paper-based test that detects metabolites of the TB drug in urine. The metabolite reacts with chemicals in the paper, revealing a simple numerical code. A patient would take the test daily and text the code to a central database. Those who take the drugs consistently for 30 days would be rewarded with cell-phone minutes.
In a pilot study in Nicaragua, the researchers worked with local scientists to ensure the accuracy of the test strips, testing them on urine samples collected from TB patients. They also determined that the strips could be stored reliably and that they worked as well in humid Nicaragua as they did in New England.
The team is developing a device that dispenses the paper tests in the proper order, so that the sequence of the codes will correspond to that stored in the database. A larger trial recently began in Karachi, Pakistan.