Hi, martin, I did a quick search on the internet regarding your question/concern. Didn't find anything specifically relating to Shanxi, and what you mentioned egarding a swine-flu related ban for non-Chinese (but that doesn't mean it's not happening).

The majority of hits I got concerned the quarantining of some British students in a Beijing hotel some time back, and a couple of fleeting references to swine flu a while back in Sha'anxi (not Shanxi) province; April I think it was. Nothing found that connected Shanxi and swine flu and foreigners.

I'll keep looking...

Hope someone can offer you more info than I've been able to provide. Are you presently in Shanxi, or planning to go there in the near future?