Viral RNA and infectious influenza virus on mobile phones of influenza patients in Hong Kong and the United States

Mobile phones are among the most highly touched personal objects. As part of a broader study on the contribution of fomites to influenza transmission, between 2017-19, we swabbed mobile phones from 138 influenza patients in two locations. Influenza viral RNA detection rates were 23% (23/99) and 36% (14/39) in Hong Kong and Maryland, respectively. In Hong Kong, infectious influenza virus was recovered from 3/23 mobile phones. Mobile phone influenza contamination was positively associated with upper-respiratory viral load and negatively associated with age. Cleaning personal objects of influenza patients should be recommended and individuals should avoid sharing objects with influenza patients.