Question: I think the question title says it all:

Given a distribution board in the house (220 VAC), is it enough to shut off only the room's fuses, or must one shut off the main switch for the board before safely touching wires? 

Does the answer depend in any way on the fuse type?

Answer: 
And here is why you check it before hand, even though you have turned off that room. People get into Junction boxes and re-wire - joining two separate circuits into one - in that case one circuit in the house can be fed from two breakers (as long as they are on the same phase). Always check with testor - and NOT JUST a proximity induction testor - but an actual touch the wires testor. OK. Be safe.
You say "that room". Circuits are not nearly always designated to one room or area. Many, many times a room will have some devices on one circuit while others on another circuit. It is pretty rare that rooms are strictly wired so that one circuit distinctly feeds one room.

Also, panel directories are not always extremely accurate. So something that says the breaker is for one room might also have other things one it. 

Again, a tester is the ONLY way to be sure what you are working on is dead. IMO you should not even pick up a tool or open a box until you are in possession of a decent tester.