― Question by : If tuberculosis is easily spread airborne, how is everyone not carrying it at the least? My mother carries tuberculosis, and I've recently got the PPD test to be able to volunteer at my local hospital this summer. I'm 99% sure the test is positive. And I was doing research and read it was airbrone. If so, how is everyone not infected with tuberculosis or have latent TB? Best answer: Answer by MagnusMossTB is is air born, but you are only contagious when you have active TB..... [...].