The coronavirus was spread throughout China by travel associated with the Chinese new year. Now the virus is being spread throughout the US by travel associated with spring break.
The coronavirus escaped from China, because governments and airlines waited too long before they stopped flights in and out of China. The US government and airlines are waiting too long to stop domestic flights in the US.
Government carelessness is also a contributor to the spread of the virus. President Trump agreed that the US passengers who had been quarantined for weeks aboard the Diamond Princess cruise ship in Japan who were free of the virus would be flown to the US on two chartered planes, but the 14 Americans who tested positive for the virus would remain in quarantine. However, State Department officials and a top US health official instead flew back the infected Americans on a plane with uninfected passengers. It is entirely possible that the health passengers were infected and now are spreading the virus.
In Europe the virus is now spreading from Italy, because European Union officials refuse to implement border controls. By refusing to take sensible actions until the situation is out of hand, governments then resort to widespread mandatory quarantines.
The virus appears to be an engineered bioweapon that escaped from the level 4 lab in Wuhan. My understanding is that the development of bioweapons is prohibited but nevertheless is done in a number of countries. The fact that governments are complicit in the illegal activity means that they cannot acknowledge that the virus is man-made.
To prevent future escapes, publics must demand the cessation of bioweapon research.
Globalism is also a culprit in the spread of the virus. The interdependence that globalism creates means that there is constant travel across national borders that serves to spread illnesses globally.