Germs may be the carry-on no one talks about, but that doesn't mean the little buggers aren't hiding throughout airport terminals and on planes, waiting to make us sick.

Recently Coverall Health-Based Cleaning Systems, which specializes in commercial cleaning programs, analyzed data from airports with the aid of a microbiologist to pinpoint the top five germiest places in airports, making some illuminating -- if gross -- discoveries.

"An airport should ensure that an effective hygienic cleaning program is being executed multiple times every day," Peter Sheldon vice president of operations and development of Coverall told HuffPost Travel in an email. Additionally, airports should be providing educational material (like signs in restrooms) and making sure proper hygienic supplies are available (like stations dispensing hand sanitizer.)

As for the airplane, "studies have shown that plane restrooms, tray tables, seat belts and really all surfaces in a plane rarely get cleaned," said Sheldon. Cleaning crews have little time to properly clean between flights. That might be why, as Sheldon points out, a survey that revealed 60 percent of sink areas in plane restrooms tested positive for coliform bacteria.

Gross.

For travelers, Sheldon recommends practicing proper hand hygiene, using hand sanitizer, keeping hands away from the face, and carrying a packet of disinfectant wipes to clean surfaces before use as ways to combat airport grime.

So, what are the germiest places? Check out the slideshow below.

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  • The Airplane Bathroom

    Since the lav isn't usually sanitized between flights, it can see hundreds of users before getting a good scrub down.

  • Onboard Magazines

    One study found that as many as 30% don't wash up after using the airport restroom. And, there's all the coughs and sneezes and those that lick their fingers to turn pages. Where do you think those germs end up?

  • The Water Fountain

    The tap water on the plane isn't much better, it can contain contaminants like E. coli and others thanks to questionable techniques for filling the tanks and improper/malfunctioning filter systems.

  • Airplane Blankets and Pillows

    There's a good chance you could be using a pillow that's been drooled or sneezed on within the past hour.

  • The Security Line

    Always wear socks when traveling. Who knows what you'll pick up from others who have gone barefoot through the line before you.

  • Quick Tips for Germ Free Traveling

    Are you traveling this summer? The Doctors share must-know travel tips for staying healthy while away from home.