The World Health Organization says it does not recommend trade and travel restrictions in the wake of the new coronavirus outbreak.
But that has not stopped at least 22 countries from imposing some form of travel restrictions on people coming from China.
That includes the United States, Israel, the Philippines, Australia, Singapore, Malaysia, Vietnam, New Zealand and North Korea; Indonesia and Iraq have issued temporary travel bans on people travelling or transiting from the mainland.
China's neighbours like Russia, Mongolia and Nepal are closing their borders and checkpoints, while others are introducing stricter controls.
Singapore, Vietnam, Russia, Sri Lanka, Bangladesh, Kazakhstan and Mozambique have temporarily stopped issuing visas to Chinese nationals.
And nearly 40 airlines from across the world have stopped or partially suspending operations to and from China.
Something else appears to be spreading fast to communities big and small, due to ignorance and misinformation.
Al Jazeera's Andrew Chappelle has more.