On Friday, Texas public health officials estimated that a measles outbreak had likely spread to between 200-300 people, across five counties in the western area of the state. Then, on Sunday night, word started coming out about three cases in Eastern New Mexico. Given measles is one of the most infectious diseases known to humankind, and that it takes 7-14 days for symptoms to become apparent, it’s possible that by next Sunday, more than a thousand people will be sick and the outbreak will have crossed more state boundaries.