Germs can be found on door handles, light switches, surfaces and objects such as telephones and computers (fomites) and even in the air (aerosols).
As a result, many medical devices such as endoscopes, catheters and joint prostheses can become contaminated and colonised by microorganisms and then be a source of nosocomial infections. These infections are often linked to the formation of biofilms, clusters of microorganisms attached to a surface.