You may want to pack some disinfectant wipes the next time you travel.

When you stay in a hotel room, you usually expect that staff have cleaned it thoroughly after the last guest stayed there. But this is not always the case, and even regular cleaning can leave travelers open to other people’s germs, experts say.

In one 2012 study presented at the general meeting of the American Society of Microbiology, 81% of surfaces sampled had some fecal bacteria. Researchers found that light switches and TV remotes were among the objects most heavily contaminated with bacteria, and toilets and bathroom sinks also had high levels of microbial organisms.