Most of the bacteria were unsurprisingly microbes found on the skin, while others matched those found in mouths, and even some in vaginas, according to the study conducted by New York University's Center for Genomics and Systems Biology.
"We are finding viable bacteria that can be taken from paper currency," said Jane Carlton, the lead investigator of the study and director of genome sequencing at NYU's Center for Genomics and Systems Biology. "That means that money could function as a form of transmission."
The study was part of a pilot project to identify bacteria and health trends in New York City. For example, some of the findings pointed to the prevalence of pneumonia on paper money during winter time. The researchers found that bills collected in winter, versus the summer, were more likely to have microbes of community-acquired pneumonia; suggesting that money could be playing a role its spread.