Don’t go to Romania if you are a hypochondriac

Last week, the 29th First Annual Ig Nobel Prizes have been awarded. Every year the Annals of Improbable Research award this prize as an ironic answer to the Nobel Prize to peer-reviewed scientific research that first makes you laugh and then makes you think.

My favourite this year, hands down, was the prize for biology, awarded for a study that showed that dead magnetised cockroaches behave differently than live magnetised cockroaches. Don’t say.

But this is a blog about economics and finance, so let’s have a look at this year’s economics prize. It was awarded to Habip Gedik, Timothy Voss and Andreas Voss for testing which country’s paper money is best at transmitting dangerous bacteria. This is a classic example why the Ig Nobel Prizes are so valuable. At first glance, this seems like a ridiculous thing to do, until you realise that paper money is one of the most circulated objects of everyday life. We hand banknotes to other people all the time and accept their banknotes in return, and with it comes the risk that dangerous bacteria could spread through this channel. If there is an epidemic of antibiotics-resistant bacteria, the simple act of everyday payments could spread the epidemic, particularly in developing countries where hygiene standards may not necessarily be as high as in industrialised countries.

So, the researchers took banknotes from seven different countries, sterilised them and then inoculated them with three different types of dangerous pathogens:

Meticillin-resistant Staphylococcus aureus (MRSA), an antibiotic-resistant superbug that exists on all our bodies (typically in the nose, armpits, groin and buttocks) and don’t cause any symptoms as long as they are on our skin. But once they get inside our body, they can be extremely hard to treat and are potentially deadly.

Vancomycin-resistant enterococci (VRE), antibiotics-resistant gut bacteria that may cause severe illness if they enter the bloodstream of a patient. Again, most of the time we have enterococci that are perfectly harmless in our intestines, but that can become dangerous if they enter our bloodstream.

Escherichia coli bacteria that produce enzymes of the Extended Spectrum Beta-Lactamases (ESBL). Honestly, I have no idea what that last sentence means, but apparently, these bacteria are prevalent in the human gut and again harmless most of the time but can cause serious infection if they enter the bloodstream.

All of these bacteria can be spread by touching other people and potentially via the exchange of banknotes.

The results of the study were quite telling. The table below shows the amount of growth of these antibiotics-resistant superbugs on the banknotes of different countries. There was significant growth of all three of these bugs on the Romanian Leu, while the Euro showed strong growth of ESBL E. coli and the US Dollar showed strong growth of MRSA. This means that these bacteria can potentially be transmitted via banknotes. To test that the researchers performed a second test in which participants handled the infected banknotes for 30 seconds and then dunked their fingers into a petri dish to see, which bacteria had been transmitted. 

It turned out that after touching the Euro banknotes, no bacteria were spread but for both the Romanian Leu and the US Dollar bacteria were transmitted to the fingers of people who handled the notes. In short, the Romanian Leu is one of the most dangerous banknotes to handle when it comes to spreading diseases.

This also does not bode well for the Sterling. The authors did not test British Pounds, but the Romanian Leu was the only plastic banknote in their sample that was made from similar material as the new British banknotes. The other banknotes were all cotton- and paper-based traditional banknotes. One might want to test the new Sterling notes if there is an increased health risk emanating from them.

Growth of antibiotics-resistant bacteria on banknotes

Source: Gedik et al. (2013).