French here.
My first thought is ‘beurk’. ‘Pouah’ and 'Aaah dégueu !" will be common too.
I’ll often hear just the “aaaah”, as you typed it (or a similar noise which doesn’t really sound the way it’s spelled here - I can’t seem to figure out how to represent the sound!) Ouach is, IME, more common than beurk, and I hear dégueu a lot. Some people in Québec seem to have adopted the English “ewww” as well, particularly if they are bilingual.
Thanks for all the replies. It was one of those “Ask X the answer to this question – He’ll know!” situations. In this case, of course, X had no clue. The Teeming Millions have, however, saved his reputation yet again.
Yeah, "Merde! and “Zut!” are used in the same context as “Shit!” and “Nuts!” or “Doh!”
Not so much in the context of “Ewwww.”
I can see someone making a face and going “ouffe!” if they were disgusted by a bad smell, specifically.
Supered in an opera this summer that was directed, I believe, by a Quebecois. He was quite fond of this particular interjection. Contextually, it had as much frustration or somewhat humorous long-suffering patience as disgust; he’d generally heave an “euf” when we were doing something wrong, stupid, etc.