When I come down with a viral, I go into full on "give my body the best fighting chance"-mode. Drug it up with the right drugs, drink tons of water to stay hydrated, get as much sleep as you can, treat the symptoms it's safe to treat, etc. Usually takes a few weeks to run the course, but usually a week to get to the return point. I think that's the point at which if I wasn't getting better in the next few days that I'd start to worry.