For years, doctors have struggled to get some TB patients to take all their medication, which generally involves a six-month regimen of multiple drugs.
Now a student-led group at the Massachusetts Institute of Technology has developed a way to use cell phones to let patients test themselves. And if the tests show patients are following doctor's orders, they get rewarded with free minutes.
"We're piggybacking on one of the bigger rollouts of infrastructure out there, which is wireless technology and telecom technology," said Jose Gomez-Marquez, one of the project's leaders.
The system works like this: Patients test their urine using a strip that reveals a numeric code if it detects TB medicine. They then text message the code to their health care provider and get credit toward incentives such as free minutes.
The in-home tests also eliminate the need for health care workers to make several patient-monitoring visits a week, a routine that is often impractical in remote places, Gomez-Marquez said.
Mobile phones are good tools for the project because they are common in the developing world, where it's often cheaper to erect cell towers than miles of poles and wires, Gomez-Marquez said.
Dr. Mario Raviglione, director of a World Health Organization program to fight TB, called the MIT idea "creative." But he said personal visits must continue because systems that depend heavily on patient self-reporting have often failed.
"I would think it's a dangerous game to rely only on incentives," he said.
In 2006, the most recent year statistics are available, 9.2 million people worldwide were diagnosed with tuberculosis and 1.7 million died.
The disease can be cured with a steady regimen of drugs. But many patients start feeling better and stop taking the medicine too soon. Others abandon the drugs because of side effects such as nausea, fever and rashes.
If the drugs are taken only sporadically, the bacteria build up resistance. The WHO estimates that 5 to 10 percent of TB deaths are patients who stop taking medication properly.
The MIT group - which originally included five students - took on the TB problem in 2007 as part of the university's annual "IDEAS competition," which challenges participants to solve various world problems.
Under the TB treatment system used by the WHO, the relationship between the patient and health care worker can get adversarial, said Elizabeth Leshen, an MIT junior working on the project.
"We wanted to do something that takes the health care worker out of the supervisory role and puts him or her back into the patient care role," she said.
Cell minutes were chosen as an incentive because patients want them and phone companies are willing to give them out, said Gomez-Marquez, who added that other incentives and reporting methods can be tailored to different regions.
A small study of 20 patients in Nicaragua last year indicated the MIT system could work, and a larger study in Pakistan is planned for this summer. The team is trying to raise the $200,000 for a full-scale clinical trial.
The WHO's Raviglione said the MIT group's program could be an asset, particularly in developed countries, where people are more familiar with technology. But he said it must be combined with regular visits from health care workers or community leaders who can ensure patients take their medicine.
Before personal visits became routine in the 1990s, death rates from tuberculosis were estimated at 40 to 50 percent, according to the WHO. After officials began making visits as part of a broad strategy to fight TB, that figure dropped to 15 percent.
"Human contact is essential for people who have to take drugs for a long time," Raviglione said.