Shanghai medical teams aiding Wuhan

The letter read: "We'll always keep in our hearts the fact that you came to support Wuhan and are risking your lives to protect ours. We have seen that love and hope is spreading faster than the virus."

Xu, who works at Shanghai East Hospital, said, "Many people are referring to us as heroes on the internet, but actually we're just doing our job."

By Wednesday, around 2,100 Shanghai medical professionals specializing in critical medicine, respiration, infectious diseases and nursing had arrived in Hubei to provide support. Two days earlier, 19,900 medical workers from across the country arrived in the province.

After her first eight hours on duty tending to critically ill patients at Wuhan Jinyintan Hospital, Xu wrote a letter to her father, stating: "Who isn't afraid of getting infected by the virus? But we have to go to the front-line of this battle. If we don't, who will?"