Studies Shows Touch is Highly Effective at Spreading Rhinovirus, Air Alone is Not.

"When young, healthy adults touched either coffee cup handles or plastic tiles that had been contaminated with rhinovirus, and then touched their faces, half of them came down with a cold": https://www.washingtonpost.com/opinions/five-myths-about-the-common-cold/2015/11/13/2588a7ba-829f-11e5-8ba6-cec48b74b2a7_story.html?utm_term=.a9ea8f8350e5

Is a 50% infection rate high? When airborne transmission is used alone, the transmission rate is near zero: "Under laboratory conditions, when healthy volunteers are kept with those suffering colds, it is remarkably difficult to spread the infection. This is because the mucus from the respiratory tract of someone infected has to get directly into your respiratory tract.": http://www.smh.com.au/news/Health/Kiss-your-fears-goodbye/2005/05/26/1116950789651.html

Another study showed transmission from fingers to eyes and nose resulted in 100% transmission rate of Rhinovirus. The study also showed that using iodine on just the hands was effective a preventing infection: http://www.jstor.org/stable/30114992?seq=1#page_scan_tab_contents