Have you recently read one of these magazines and then invested a point in pack mule ? When the effect of the magazine is over, you will get this message because you no longer have the level in strength that is required for the level in pack mule.Getting this status on pack mule perk but no status effects are listed. Why?
It's more likely that you invested a point in pack mule while you were infected. If you buy the next level in strength then the message should disappear.I did get infected but the debuff disappeared without using antibiotics. Apparently the affect stays as a permanent affect until you get affected again so you can clear.