Measles

Measles, also known as rubeola, is a disease caused by a virus, specifically a paramyxovirus of the genus Morbillivirus.

Measles is spread through respiration (contact with fluids from an infected person's nose and mouth, either directly or through aerosol transmission), and is highly contagious—90% of people without immunity sharing a house with an infected person will catch it. Airborne precautions should be taken for all suspected cases of measles.

The incubation period usually lasts for 4–12 days (during which there are no symptoms). Infected people remain contagious from the appearance of the first symptoms until 3–5 days after the rash appears.

Measles in The Disunited States of America
The country of Ohio released an artifically mutated version of the measles into Virginia in its opening move in the Ohio-Virginia War of 2093. The resulting panic and death left Virginia vulnerable to a ground invasion.

The disease was cured quietly by Crosstime Traffic, which allowed the alternate to think that the cure had perhaps come from Wabash or Pensylvania.