CDC defines a confirmed case of anthrax as 1) a clinically compatible case of cutaneous, inhalational, or gastrointestinal illness that is laboratory confirmed by isolation of B. anthracis from an affected tissue or site or 2) other laboratory evidence of B. anthracis infection based on at least two supportive laboratory tests.

Based on this definition, CDC is reporting eight confirmed cases of anthrax: two in Florida, three in New York, two in New Jersey, and one case in Washington, D.C. (in collaboration with public health officials in Maryland and Virginia).