GENEVA (Reuters) - Bank cashiers and others working with large quantities of paper currency are vulnerable to catching various types of flu from the germs living on notes, a Swiss researcher said on Wednesday.
Yves Thomas, head of the National Influenza Research Centre at Geneva University Hospital, said that flu viruses could survive on banknotes from 24 hours up to 17 days.
“Our studies have convinced us that it is possible to catch flu from banknotes, but the chances are very, very slim and there is no cause for concern among the general population,” he told Reuters in a telephone interview.
“All the same, bank employees and others who have to handle large quantities of notes daily could be at risk,” Thomas said. “This could be reduced if they wear gloves, or even a mask for those who have to examine currency closely.”
Scientists have long known that various types of germs and bacteria can survive on paper currency, but until now medical experts have thought that flu only spread through small droplets in airborne transmission.
But Thomas said his team found that some types of flu virus could also survive and spread on everyday objects, like doorhandles as well as banknotes.
When the researchers put different amounts of virus on notes in laboratory conditions, the common H1N1 variety of “influenza A” survived for only a few hours.
However, the H3N2 variety stayed active for up to three days. When mixed with nose mucus from children already suffering from flu, it survived for up to two and a half weeks.
No attempt was made to infect anyone with the samples, he said. “But it is clear that in theory, the virus could infect people handling infected banknotes and then touching their noses or mouths.”
The team used only common flu viruses known to be passed easily between humans, and did not seek samples of the deadly bird flu H5N1 virus, which has devastated bird populations but is not known to be responsible for human-to-human infections.
“H5N1 is notoriously difficult to work with and it is not easy to obtain samples,” Thomas said.
Reporting by Robert Evans; Editing by Jon Boyle