Harrison County is Biloxi, Gulfport, Long Beach, and Pass Christian, most of the population of the hardest hit area of MS. The local news here in TX showed some video from Gulfport, and most of the buildings fronting the Gulf that weren't massive were pretty much flattened. So perhaps this count of 50 has gotten most of the victims in the most populated areas of MS, and possibly might not go up much more. One can hope.
Plus there will definately be some from Pass Christian/Bay St Louis/Slidell
I fear this one will be in the hundreds.
It is not possible they have made it into all dwellings this quickly following the storm. I don't have a death toll wish, it takes time to canvass the areas. On the flip side, if most of the residents evacuated, then this could be a reasonably accurate number.