It’s expected. At a job interview, during an introduction, when saying goodbye . . . The handshake is as American as apple pie.

But — eewww — just imagine where that person’s hand might may have been before being clutched into yours! Touching a subway rail ... flushing a toilet ... changing a diaper ... maybe blowing a nose …

As a variant of swine flu H1N1 makes its way around the world, escalating the fears of millions and prompting many to wear face masks, perhaps it's time to ask:

Is it time to stop the handshake?

Absolutely not, says Dr. Keith Ablow, psychiatrist and FOX News contributor.

“We’ve had threats of swine flu before, and we have faced other communicable diseases before without changing our basic pattern of interacting socially,” Ablow told FOXNews.com.

“Stopping the handshake could have a negative effect. We need human touch and genuine communication more than ever right now.”

For centuries, Americans have been shaking hands when greeting others, whether they be dear old friends or someone they are meeting for the very first time.

Where the tradition originated, no one knows for sure. Some say the handshake dates back to ancient times, when men would extend a hand as a show of peace — a physical way of saying, “Look, I’m not holding a weapon.”

Fast-forward to the 21st century, and the handshake is much more than just a greeting. It's become a quick way to assess someone's character.

Dr. Manny on the Demise of the Handshake

But putting your hands to your mouth or nose after shaking hands with a person who is coming down with a cold or the flu is a great way to transmit that disease to yourself.

This week, as a precautionary measure, Costa Rica’s health minister urged citizens to temporarily stop greeting one another with the traditional kiss on a cheek — leading some to ask whether other traditional greetings, such as the handshake, should also be discouraged.

Again, Ablow says no, because he fears an epidemic more serious than the flu is the dehumanization of society by technology.

People ultimately feel more isolated and alone as we increasingly reach out to others with BlackBerries and iPhones, online social networks and instant messaging, Ablow said. A lack of physical touch can only increase that feeling, he said.

“It’s time to encourage people to shake hands to reaffirm their humanity and immunize them against loss of their emotional connections to one another,” he said.

Dr. Michael Anderson, interim chief medical officer of University Medical Hospital in Cleveland, Ohio, said whether people are worried about swine flu or the common cold, they need to use basic common sense — and that doesn’t include stopping the handshake.

“There are other ways to protect yourself, like using an alcohol-based sanitizer, which I use two or three times an hour,” Anderson said. “I’ve probably shaken the hands of 10 colleagues today. I think it’s a wonderful social greeting.”

The bottom line: Go ahead, shake a hand. But wash up afterward, either with soap and water or hand sanitizer, before touching your face or eating.