Reducing the risk of mouth to mouth transmission of pathogens via reusable, machine-read, parking tickets. An observational cohort study

The carparks at our hospital are accessed using reusable machine read tickets. In the initial phase of our study we in observed 598 staff members entering the carpark. 21.6% of them put their parking ticket in their mouth. Using UV dye we successfully demonstrated card-to-card cross-contamination. Swabs of the ticket machine yielded commensal bacteria: coagulase negative staphylococci and a Bacillus species.

After placing a poster on the ticket-reading machine highlighting this potential infection risk, a further 1366 observations resulted in a statistically significant and persistent decline in the proportion of staff putting their carpark tickets in their mouths (p<0.001).