A recent experiment mapped the bacterial travellers on the New York Subway system and found that grabbing a handrail transmits the same number of bacteria as shaking hands with 10 000 people. An average of 2 million colony forming units were found per square inch, which for frequent travellers, equates to 900 times more than airplane tray tables!
Thankfully, most of the bacteria found were harmless although some bacteria that can cause diseases, such as food poisoning were seen. Interestingly, although over 600 known species were detected almost half of the DNA material located did not match with known species suggesting we still have a lot to learn about the microbes we are sharing the environment with.
Several other subway studies are underway across the world including Shanghai, Tokyo and Paris. Researchers aim to use the data to develop maps that allow them to track bacteria and predict or improve responses to outbreaks of illness.
Also calls to mind the Portuguese bus studies (and many other similar studies) that documented MRSA contamination – 36% of sampled buses in Lisbon and 26% in Oporto ! The buses servicing the local teaching hospital were more likely to be contaminated…
Until then- best keep washing your hands or using alcohol hand rub!