Whooping cough
From Tardis Wiki, the free Doctor Who reference
Whooping cough was an Earth disease. Before the late 20th century it was often fatal.
Barbara Wright caught whooping cough during the 1940s when she was 10. She was confined to her bed while she recovered and read a book about Captain James Cook to pass the time, beginning her interest in history. (PROSE: Byzantium!)
The First Doctor convinced young Craig Atkins to pretend he had whooping cough. This was so Prentice would turn off the temporal technology he was using to keep Keelmouth frozen in 1933, and reintegrate the town into the actual time period of 1999. (PROSE: Bide-a-Wee)