Check out this sign from the Delta Airlines terminal at one of the world's busiest airports ... handshaking is a big no-no until further notice. The sign, posted at the airport information desk, also advises folks to be considerate of others and wash their hands regularly.

Remember, Dr. Oz is on a crusade is on a to replace handshakes with fist bumps in the wake of the rapidly spreading coronavirus.

The reason, according to the TV doc -- COVID-19 is 5 times more contagious than the seasonal flu, and handshakes transfer 10 times more bacteria than a fist bump.

Someone might want to alert Donald Trump about the dangers of handshakes ... he's on video shaking hands with foreign leaders on his recent trip to India, and today he decided to lie about it.

Be safe out there, folks ... especially in the airport ... and remember, just pound it.