Thanks to an investigation by ABC News, we know what to watch for when dining out.
Read on -- the results may surprise you. Visible goop didn't always translate into bad bugs, and some spotless surfaces harbored major microbes.
10. Salad Bar Tongs
The salad bar tongs weren't that bad -- maybe because Americans don't eat enough salad.
9. Ketchup Bottles
The ketchup bottles weren't harboring anything too awful.
8. Bathroom Faucets
7. Bathroom Door Knobs
"The faucets, the door handles ... were some of our least germy items, because they get cleaned," [Consumer correspondent Elisabeth]Leamy said.
6. Rims of Glasses
The hidden cameras caught waiters gripping glasses right at the top where we drink, which gives pathogens a direct route into our bodies. Tests on the samples Leamy took detected multiple bacteria, including one linked with tuberculosis.
5. Tables
Here's a clue as to how tables could be so germy. Leamy and "20/20" were shown photographs of parents changing their baby's diapers at the table and toilet-training their toddlers in restaurants.
4. Salt and Pepper Shakers
Half of the swabs Leamy took from them were contaminated. How is that possible? They're used often but are rarely cleaned.
3. Lemon Wedges
One of the most frequently occurring contaminants in the test results was fecal matter. Half of the lemon wedges tested were tainted with human waste.
How does fecal matter get on lemons in the first place? Cameras caught restaurant workers grabbing lemons with their bare hands, reaching in again and again without gloves or tongs. If they haven't washed their hands well after using the bathroom, germs spread.
2. Menus
Leamy found the bacteria that causes staph infections on one, and the germs that cause strep throat on another.
1. Seats
Seventy percent of the chair seats Leamy tested had bad bacteria on them -- 17 different kinds, including strains of E. coli. Why? All customers sit on them, and most restaurants don't think to sanitize them.
So what can you do? For starters, Leamy advised, the next time you go to a restaurant, take a seat, order your food -- then go wash your hands before you eat.