Over 150,000 people from all over the world come to America for the Superbowl, including from China.
Coronavirus is a top RNA virus meaning it can mutilate and change it's properties/symptoms quickly making it hard to detect or contain.

The infected are also asymptomatic for 3 weeks, meaning they show no symptoms until after 14 days to 3 weeks. Despite the screening measures inplace to detect infected Superbowl attendees, it's almost futile as the infected can successful walk passed the screening rub shoulders with the excited crowd. The newly infected travel back to their homes carrying the viruses to the families.
Inotherwords, if one asymptomatic carrier can infect 4 people within the duration of 3 weeks. Then 4 asymptomatic carriers can infect 16 people in few weeks. And the pyramid multiplies, hence the need for a serious quarantined measures by a developed government.
Several people in China have smuggled videos claiming that the efffects of the Coronavirus are very serious and politically downplayed by the government inother to protect their economy.
Hospital workers in Hongkong have recently gone on strike in a protest demanding their government to close the China borders.

SOURCE from video:

https://www.brighteon.com/7d101334-a27e-43f4-9e88-4d31388abc53

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