As of July 8, 2003, a total of 71 cases of monkeypox have been reported to CDC from Wisconsin (39), Indiana (16), Illinois (12), Missouri (two), Kansas (one), and Ohio (one); these include 35 (49%) cases laboratory-confirmed at CDC and 36 (51%) suspect and probable cases under investigation by state and local health departments (Figure 1). Eleven cases were excluded from those reported previously because they met the exclusion criteria outlined in the updated national case definition, and one new case was added (1). The number of cases increased from May 15 through the week ending June 8 and declined...