A fomite is any inanimate object or substance capable of absorbing, retaining, and transporting contagious or infectious organisms (from germs to parasites) from one individual to another.

There are many examples of fomites with respect to medicine. Contaminated shoes may spread hoof and mouth disease. Other examples include tools such as laryngoscopes that are not properly disinfected between uses, dirty towels, eating utensils, and surfaces such as floors, walls, and tables may all serve to spread disease.

Researchers discovered that smooth (non-porous) surfaces transmit bacteria and viruses better than porous materials; so one is more likely to pick-up a disease from a door knob than from paper money. The reasoning is that porous, especially fibrous, materials absorb and trap the contagion, making it harder to contract through simply touching.

Etymology

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The word fomite is a back-formation from the plural fomites, which was originally the Latin plural of the singular, fomes (rhymes with "homies"), literally meaning touchwood or tinder. As a Latin plural, fomites was originally pronounced like the English word concatenation "foam" + "it" + "ease"; but "foe" + "mites" has now become a common pronunciation, and "fomite" (also pronounced with a long 'i') is now an accepted synonym for fomes.

Microbiology