Thank you for the suggestion, but at the moment I don't see any need to widen the investigation to local health authorities since Cathay seems to be taking the case very seriously. Just got a follow up fax from Customer Services, saying they are coordinating an "immediate investigation" with the caterers.

Very impressed by their quick response so far. Although it does make me wonder if others also reported food poisoning after taking the same flight. Or perhaps it's just that Cathay moves quickly to investigate any case of food poisoning.