U.S. Agriculture Secretary Tom Vilsack says he's not ready to declare the Midwest bird flu outbreak over.

While no new cases of the H5N2 virus have been detected over for over a month, Vilsack told The Associated Press on Monday that the threat hasn't passed.

Vilsack said poultry producers have caught a break thanks to the summer weather because warmer temperatures tend to kill the virus.

But he also said his agency is aware of the need to be prepared in case the disease reappears this fall. He noted that USDA officials and poultry industry groups plan to meet in Iowa next week to discuss those plans.

Bird flu has cost Midwest poultry producers about 48 million birds, mostly egg-laying chickens in in Iowa and turkeys in Minnesota.