In a cell phone culture, government news casts can recommends watchers in X district to txt others in their district on their contact lists when an endemic worsens in that specific area. Likewise when threat levels decrease. This would be served best when cellular technology starts being able to filter where you reside and where your contacts reside from some kind of IP information.
Psychologically, txting people would creates social contact, which is listed in this week's reading as a way to manage panic. It also gives something for people to do, which is another way from this week's reading to manage panic.