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.