When did the Zhengzhou epidemic begin?

In July, 20021year, the local epidemic situation in Zhengzhou was discovered on the evening of July 30th17th, but it may have started earlier than the 30th. Because the case was found to be positive in routine examination, the place where the case lived and the place where it passed were closed for management. 3 1 day, local cases 12 cases were found, and 20 cases were asymptomatic infected. The most important thing is that the epidemic situation in Zhengzhou mainly occurred in hospitals, where the flow of hospital personnel is relatively large, and there are more people who see a doctor every day. It is estimated that the local epidemic situation in Zhengzhou started earlier than July 30th, and it is likely to start on July15th. On July 5th/kloc-0 and July 8th/kloc-0, Henan released 1 new cases. However, the specific start time still needs to wait for official notice.