Tuberculosis has plagued humanity for thousands of years, and despite medical advances that can now help us prevent and cure it, the ancient bacterial disease still claims more human lives per year than any other infectious pathogen.

In a new study, researchers unveil a device meant to demystify the early stages of TB, including a peculiar delay that often precedes the onset of symptoms.

Their model could also reveal how genetic variations in patients lead to varying effects of TB, with potentially broad implications for personalized medicine.

About a quarter of our species is infected with TB bacteria, and while only a fraction of those people will become sick, that still amounts to more than 10 million new cases – and more than 1 million deaths – per year worldwide.

TB progresses slowly, with symptoms often taking months to appear. To learn more about this lag, the authors focused on tiny air sacs in the lungs, pulmonary alveoli, which host pivotal confrontations between immune cells and bacteria.