no, but you can get some more specific direction.
first, if you're using persitent connections, turn them off. this will make your logs easier to use.
second, since it sounds like you have multiple code bases accessing the same database, create a different user for each code base with exactly the same rights and make each code base log in with a different user. now when you look at the log, you can see which application is doing what.
third, if you have the query log on, then the UPDATE immediately preceding the trigger will be the UPDATE that caused the trigger.
fourth, if your apps use any sort of encapsulation for the mysql connection, it should be trivial to modify it to write the call stack at the time a query is sent to the database to a file.