Lefarge experiences a similar problem.
Approximately a month ago my ping was 30-40, and now I constantly experience 70-100.
Like the OP I have pinged several Chicago servers and peaked at around 40. Also like the OP my ping is fine in other games.
I have also tried forwarding my ports, and that didn't seem to help at all.
I live in Montreal, Quebec, Canada if that provides any useful details whatsoever.
I haven't called my ISP but I figure I don't need to now, considering it's not just me who seems to be having this issue.
Farge out.