Bacteria survive on paper

Have you held a piece of paper at work today ? Whether a patient file, doctor’s notes or reports, or a patient’s personal books and magazines, you have probably handled many papers and their invisible bacteria.

A 2011 study looks at the « Survival of Bacterial Pathogens on Paper and Bacterial Retrieval from Paper to Hands »(1)

Four bacteria – Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Enterococcus hirae – were cultured overnight in a growth medium. These cultures were air-dried on paper swatches in standard room conditions. They were then sampled and plate counted after 48, 72, 96, 144 and 168 hours, to test for bacterial growth. The authors report : « The four tested organisms showed differences in length of survival… but were stable on paper for up to 72 hours and still cultivable after seven days. » To test for the transmissibility of pathogens, volunteers’ fingertips were inoculated with a non pathogenic strain of E. coli ; the inoculum was then pressed onto sterile paper swatches. Other volunteers, whose hands had been moistened, pressed their fingertips onto the contaminated paper swatches. Bacteria transferred to the moistened fingertips were cultivated according to standard laboratory procedures.

Quantities of bacteria sufficient to cause infection or disease were found on the volunteers’ fingertips, completing the hand-paper-hand bacteria cycle.

Further research should examine the efficacy of hand sanitizers and soap in reducing bacterial transfer.