Hangzhou is the largest (2.5-million people), and capital city of Zhejiang province, a region that has served as H7N9's playground over the past few weeks.
This action comes on top of 2 other districts (1 in Hangzhou and one in Jinhua) already having closed their markets.
Shanghai closes up 31-Jan to 30-Apr, for the Spring Festival.
The Xinhua story quotes Li Lanjuan of the Chinese Academy of Engineering and director of State Key Laboratory for Diagnosis and Treatment of Infectious Diseases as predicting that...
"China will see more human H7N9 cases in the future as the virus tends to become more active during winter and spring"
...or at least, human cases appear more often then.