Gov, Henry McMaster is concerned that out-of-state visitors may be contagious.
Thousands have left New York and other northeastern areas due to the heavy contagion there.
To date, more than 18,000 people in the tri-state area of New York, New Jersey and Connecticut – most of them in New York City – have tested positive for the potentially deadly virus.
McMaster requested that all out-of-state visitors self-quarantine for two weeks immediately on arrival. 
That applies only to visitors planning a stay for two or more nights.
How this could be monitored is unclear.