I, would just leave it for a while somewhere isolated, do a little research on the virus; in general, some can survive outside the body on surfaces for days but then die off. The coronavirus is mostly spread via animal contact with humans. I wouldn't throw out your figures over this. If you're really really worried maybe ask at the doctors next time you're there before you open the package. I am sure that the medical doctors in practice are briefed on this virus as part of there employment and medical responsibilities.
I am not a doctor or scientist or anyone with medical or scientific knowledge; If it were me, I would ask at the doctors next time your there. Maybe even Australia post can assist you if you give them a call. I'm sure Aust post have already encountered this question to cover themselves they would have sought advice.
It's my opinion hope this helped.