Laboratory Results for Case Classification - Probable

• Definition
• Clinical symptoms or exposure compatible with plague.
• The specimen or recovered isolate is positive by any one of the following tests:
• Direct fluorescent antibody (DFA) staining.
• DNA detection by PCR or plasmids.
• Immunohistochemical staining (IHC).

OR

• Single serum specimen that has a minimum passive hemagglutination/inhibition (PHA/HI) titer of greater than or equal to 1:10 or a positive enzyme-linked immunoassay (ELISA) titer. Known negative and positive serum samples must be run together with test samples on each test.