Downton Abbey, episode 2.8.  

Violet, Dowager Countess of Grantham : “Wasn’t there a masked ball in Paris when cholera broke out? Half the guests were dead before they left the ballroom.”

Robert Crawley, Earl of Grantham :   “Thank you, Mama. That’s cheered us up no end.”

A few decades ago I covered a cholera epidemic in Bangladesh. Forty thousand dead. The last time I thought about that trip was while watching the Downton Abbey episode quoted above.

Downton writer Julian Fellowes clearly knows nothing about cholera. 

Nobody dies of cholera at masked balls because people shit themselves […]