Tuberculosis, now largely controlled in the industrialized world, remains a stubbornly persistent killer in most of Africa, as well as parts of Asia and South America. The spread of multidrug-resistant strains of TB has slowed progress against the devastating disease, which is estimated to strike more than 10 million people annually. Now a modified soft-drink cooler, developed by researchers at MIT’s D-Lab, could make a dent in the disease’s impact.