To be ensured of bacteria free water while showering, a point of use (POU) showerhead solution can be a great option. The shower head filters the water at the very last point.
A cartridge ultrafilter is located in the showerhead and has to be replaced once in a while. This depends on the water quality and the amount of water that’s used.
PB International produces their own showerhead, which is shown on the first picture. All cartridges can be replaces really easily.