I found this interesting... but had a feeling that money was dirty.
HEALTH: STUDY: DIRTY MONEY
Your $20 bill: a hot spot for influenza
HELEN BRANSWELL
Canadian Press
June 21, 2007
The people who coined the terms filthy lucre and dirty money may have been on to something.
Swiss researchers have reported influenza viruses can survive - alive and potentially infectious - on bank notes for up to 17 days in some cases.
It's not known what portion of influenza transmission is due to touching of virus-contaminated surfaces with hands, which then touch the mucous membranes of the nose or mouth. And this study can't answer that question.
But lead author Yves Thomas said yesterday he believes the work points to a role for contamination of touchable surfaces in the spread of flu.
"When you see that the virus is still alive for several days, I can't imagine that it does not infect. I'm sure that it can infect," Dr. Thomas, a virologist at the National Centre for Influenza, said at a major international conference being held in Toronto.
"It's still alive. And it's alive in quantities that can infect."
Concerned about the possibility of an influenza pandemic, officials at the Swiss National Bank approached Dr. Thomas and his colleagues to see whether they needed to be worried that bank notes could spread infection during a pandemic, both to their staff and to the broader public.
So the scientists set about to inoculate small pieces of bank notes with several different strains of human influenza.
They allowed the notes to dry naturally and kept them at room temperature (22 C). At various points they submerged pieces of the notes in a medium, then tried to see whether the medium contained live viruses by putting it into culture.
Most of the viruses didn't last long on the money, dying within an hour or so. But one of the influenza-A viruses, H3N2, survived about 24 hours and another was viable until 72 hours, Dr. Thomas said.
Then the team decided to try to see whether mucus would enhance survival. They mixed the viruses with mucus and again inoculated bank notes. The difference was enormous.
"With secretory mucus, it's 17 days," Dr. Thomas said.
Survival time varied depending on the type of virus, with 17 days being the longest period that a virus was viable. The influenza-B virus, for instance, lasted 24 hours in mucus but only two hours without it.