Its not just chicken, though, is it? I understood it is possible in any food. You have obviously not eaten any of your chickens, so it could possibly be a bought chicken you ate, perhaps something on a barbeque maybe?
A friend of mine, has a daughter in her twenties, who has been in hospital a few days with this. She certainly has not been near any chickens, but I know, as a typical young girl she does eat out, takeways etc. As far as I know, the environmental health have not been to check her out, and she has made a good recovery.
Do hope your husband is feeling better now.