The world has become a much safer and healthy place than it was even 100 years ago. However, I feel like because of this, many younger people do not take hygiene seriously. They have not had to live through major epidemics. If these epidemics do happen in our interconnected world, it would be devastating. With the amount of entertainment the west consumes, having hygiene-focused advertisements could be a good way to change this.
With all of the things that the government makes public service announcements about, it would do us well if they would make one about hygiene and hand washing. Washing your hands is the best way to prevent the spread of diseases in society. We could educate the public on the importance of this, and illness would go down.
The spread of the listeria wasn't due to unhygienic practices in the general population so I'm not sure what that advertisement would accomplish. Most of the outbreaks are found in fruit, not matter how much you wash your hands or the fruit, the bacteria cannot be washed away, it has to be heated and no one os going to heat their fruit.
Advertisements supporting good hygiene are important, yes - but unfortunately, if people have become too desensitized to ads then they're not going to absorb the message. We need to go back to basics, teach it in school. Make it habit by forced practice rather than preaching about it on tv and the radio.