Infectious Laughter

The virus incubates in the marrow of the humerus bone and is activated by laughter. Initial symptom reported as a 'funny feeling' followed by fits. Death by asphyxiation. The scourge sweeps the globe -governments hysterical, comedians tried for war crimes, class clowns put to death. Survivors left in stitches. Only societies completely lacking a sense of humor survive. North Korea, Samuel L Jackson, and the entire Muslim world thrive.