The contents need to be sterile as well.
If the outside of the packages is contaminated, I’d guess the insides could be as well although I do realize that the outsides are more exposed to stuff so it is a good idea.
I’m thinking of stocking up on clorox and a spray bottle.
If the outside of the packages is contaminated, you will be the cause of the insides becoming contaminated. That is why I suggest cleaning the outside before opening it.