Which also sounds like, if there is a case of flu, someone gave someone a case of flu, or a cold, or the greatest risk factor of tuberculosis is having been exposed to tuberculosis.
La qual cosa s'assembla a com es propaga la grip, algú se l'encomana a algú altre, o un refredat, o el factor de risc més greu de la tuberculosi, que és haver estat exposat a la tuberculosi.