Answer: Your mouth
Clues: “Opening” and “Face”
A new study by Northwestern University reveals that there are over 600 different viruses on showerheads and toothbrushes, with each sample being unique. Indoor microbiologist Erica M. Hartmann led the study and suggests cleaning showerheads with soap or vinegar and replacing toothbrush heads on a regular basis. Erica says the majority of bacteria on your toothbrush comes from your mouth and not flushing your toilet or aerosol particles
Tons of Viruses Live in Your Toothbrush and Showerhead | TIME