# 916
There are a great many unanswered questions when it comes to how influenza viruses are transmitted. We think we know a lot of things, but we aren't sure we know them.
Aerosol transmission of the virus is hugely debated, as is the role of fomite transmission (inanimate objects). Large droplets, from coughs and sneezes, are assumed to be the primary vector. But even that isn't proven.
The influenza virus can remain `alive' (a subjective term with a virus) on various surfaces for differing periods of time. Much depends on the ambient conditions (temperature, humidity, UV light), and the type of surface.
This illuminating article from our favorite Flu reporter, Helen Branswell.
Money can make you sick, researchers say
Jun 20, 2007 04:39 PM
Helen Branswell
Canadian pressThe people who coined the terms filthy lucre and dirty money may have been on to something.
Swiss researchers have reported that 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 the 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 Wednesday 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," Thomas, a virologist at the Swiss National Centre for Influenza, said at a major international conference, Options for the Control of Influenza.
"It's still alive. And it's alive in quantities that can infect."
Concerned about the possibility of an influenza pandemic, officials of Swiss National Bank approached Thomas and his colleagues to see if they needed to be worried that bank notes could spread infection during a pandemic, both to their staff and to the broader public.
While virus samples only remained viable for a few hours on bank notes in their initial tests, when researchers added the virus to mucus (which would likely accompany coughs or sneezes) and placed it on the money, it survived for up to 17 days.
Money is problematic, in that it is normally kept in a wallet, protected from sunlight and UV rays, and also protected from the drying effects of the air. It can pass from hand-to-hand several times a day. It isn't stationary, and could be an effective vector of the influenza virus.
Exactly how important this route of transmission will be is unknown. Banks and the Federal Reserve are apparently making plans on how to handle, and disinfect, money.
Giving new meaning and respectability to the term money laundering.
