Really? I remember reading a report in New Scientist in late 1995 written by two guys at Vancouver University (I haven't found the reference for you yet).
The jist of the report was that they had examined a considerable number of chopping/cutting boards made from several different types of wood, and the hygiene implications.
After infecting the boards, tests were carried out, and from what I can remember, after 3 hours there was a dramatic reduction in the bacteria present, and after 24 hours no detectable live bacteria were left. This was because the wood has natural antiseptic substances in it, which is one of the reasons it doesn't rot except when attacked by fungi.
If it were the case that wood is so unhygienic for cooking, we should all be suffering regular food poisoning from the use of wooden rolling pins, spoons, meat tenderisers, chopsticks, breadboards, chopping blocks, bowls..................
If you want an unhygienic surface try plastics.