1. Grocery store
Germiest items: Shopping cart handles and seat buckets
Watch out! Shopping cart handles are a breeding ground for infectious viruses and gut-wrenching bacteria.
2. Children's playgrounds
Germiest items: The swings, jungle gym and other equipment Playgrounds are germ minefields. Kids touch everything they see and often put them in their mouths.
The largest threat is from fecal bacteria from bird poop on playground equipment and diaper-wearing tots.
3. Public restrooms
Germiest item: Sink
Most women worry about public toilets. Well, you can sit a little easier now: The porcelain throne is not the biggest restroom offender. It's the sink.
Bacteria swarm on the sink tap or faucet handles, Gerba says, because we touch them right after using the toilet.
The sink tap is a wet, moist environment, so bacteria can survive there longer. Watch out for soap dispensers, too, because they're handled by many filthy hands.
Germiest items: Telephones and desks
In a study of 113 work surfaces in offices in five of the nation's big cities, more than 25,000 bacteria hitching a ride on telephones. Desks and computer keyboards followed close behind.
In fact, your desk has 400 times more germs than a toilet seat! Why? People don't disinfect surfaces in offices.
Another danger zone: Inside desk drawers, where workers stash food.
Bacterial levels in women's offices were nearly three times higher than in men's.
Germiest items: Table surface, high chairs
Contaminated food isn't the biggest threat at restaurants - it's the rag used to wipe the table "clean."
When busboys wipe down a table or chairs, their dirty rags may be spreading a small film of E. coli,.
They should put disinfectant on the rag after each use, but studies show that the same cloth was used on more than a dozen tables before it was disinfected.
High chairs harbor fecal bacteria too, because they hold diaper-wearing tots.
Germiest items: Countertops and surfaces
Libraries appear to be tidy, sterile places, but they crawl with as many germs as a fast-food restaurant.
Why so filthy? Lots of people shuffle through and peruse books, log on to computers and touch countertops.
7. Cruise ships
Germiest item: Handrails
Cruise ships are like floating cities, packed with thousands of people in a small space. That also makes them incubators for viruses and bacteria.
From 2001-2005, gastrointestinal illness on ships increased 25.6%, according to a CDC study: The culprit? Norovirus.
Some of the largest outbreaks occurred in 2002-2006, when new strains of norovirus emerged," says Capt. Jaret Ames, chief of the CDC's Vessel Sanitation Program.
Noroviruses are resistant to routine cleaning procedures and they're easily transmitted in places people congregate, such as dining rooms, drinking fountains and shared restrooms.
They're hard to avoid on a cruise ship. As soon as you step out of the cabin you're in public area.
Germiest item: Escalator handles
Don't hang onto the escalator handrails. They're teeming with germs, according to a study published in a 2005 issue of the International Journal of Environmental Health Research. Scientists took samples from dozens of escalator handrails across the country and found 19% showed high bacterial contamination.
The sheer volume of people who touch escalator handles makes it a bacteria hot spot.