In my Conversation with Violette Verdy in the new, Winter 2018-19 Ballet Review, she says that when she saw Le Clercq dance in Paris in 1956 New York City Ballet had just come from Venice. But Venice had been a month earlier. They had just come from Antwerp.
From what Verdy saw in the wings, Le Clercq was experiencing some stiffness in her legs, shaking them out over and over again. Ten days later she was paralyzed.
It is commonly and probably correctly assumed that Le Clercq was exposed to polio in Venice, which is probably why Verdy telescoped the time frame.
I’ve kept it as she said it, however, because I believe the interview subject should be allowed to talk freely, without intervening corrections by the interview author.
Verdy was, of course, inimitable, and I loved having lunch with her that day in 2009.