(Reuters) -The United States has declared monkeypox a public health emergency, the health secretary said on Thursday, a move expected to free up additional funding and tools to fight the disease. The U.S. tally topped 6,600 on Wednesday, almost all of the cases among men who have sex with men. “We’re prepared to take our response to the next level in addressing this virus, and we urge every American to take monkeypox seriously,” Health and Human Services Secretary Xavier Becerra said at a briefing. The declaration will improve the availability of data on monkeypox infections that is needed for…