In this scenario you would awaken from a coma naked in a deserted hospital. You will discover that while you were comatose, a virus had spread uncontrollably among the populace; the result of which was that most of the population devolved in to vicious, psychotic, bloodthirsty psychopaths.
As you leave the hospital, you will discover that your city/town is completely deserted and rife with signs of catastrophe. You will then be discovered and chased through the streets by infected people before being rescued by other survivors.
The disease will spread rapidly through bodily fluids (blood, saliva, etc.) so it will be tantamount that you take extra care to avoid having one of them vomit in your face or otherwise.
You will have to survive indefinitely and hope that the infection has been quarantined and that there are survivors looking for you.