ATLANTA (AP) — The current West Nile outbreak is one of the largest in the U.S., with four times the usual number of cases for this time of year, federal health officials said Wednesday.

It’s still too early to say how bad the year will end up because most infections are reported in August and September. But never before have so many illnesses been reported this early, said Dr. Lyle Petersen, of the Centers for Disease Control and Prevention.