Germs Lurk on Planes, Trains and Buses

Nov. 12, 2006 — -- Millions of Americans climb into buses, subway cars and planes every day, but do they know what's climbing in with them?

"You should probably take some precautions," germ expert and University of Arizona microbiologist Dr. Chuck Gerba said. "You never know who is the last person who grabbed that pole or boarded that bus."

According to Gerba, when it comes to public transportation, some of the "germiest" spots are places you might not expect.

To find out what kinds of germs are lurking on the armrest or flush handle, ABC News sent Gerba on a road trip and an airplane trip.

He tested dozens of the surfaces people touch every time they travel.

Starting with the buses, Gerba said of all the restrooms he tested, the one on a Greyhound bus was the germiest. He found tens of millions of E. coli bacteria on one toilet seat.

"Finding E. coli indicates there's likely fecal matter present," Gerba said. "And if that's so, there's other types of bacteria and viruses that can be present that can cause diarrhea, other types of infections, hepatitis."

Gerba was surprised to find relatively low levels of bacteria on the New York City subway. But he did find elevated levels of mold, a potential problem for people with allergies.

He was not prepared for what he found on an Amtrak train -- coliform levels in the millions on restroom sink handles. Coliform is a bacteria that can indicate fecal contamination.

He also found high bacteria levels on café car tables, and MRSA, a bacteria that can cause skin infections, on the armrests.

"We always found large numbers of bacteria on Amtrak surfaces," he said. "Usually we were finding maybe 100,000 bacteria per square inch."

Next, Gerba collected germ samples on four flights. With a lower volume of passengers, he expected the airplanes to be the least germy mode of transportation of all; they were not.