After reading this report from The Independent we should probably all be at least a little wary of travelling on public transport.

The story reports on a recent study, in which swab tests were performed on public transport in London. It showed that 121 types of bacteria and mould were present; some were antibiotic resistant bacteria. The tube (underground train) system was by far the dirtiest, with the Victoria line the worst of the lot.

I guess that we should not be surprised, as the tube system is an ideal incubation ground for bugs: warm and humid, with lots of places difficult to clean. It also confirms what we all really already know: that most people have poor hygiene.

The history of human civilisation is one of growth, interrupted by periods of no growth or even falling population (e.g. during the black plague) when new or mutated diseases become dominant. Population only starts to grow again when advances in medicine (e.g. the discovery of penicillin or the invention of vaccines) or public hygiene (e.g. the introduction of flushing toilets, drinkable water piped to houses or the banning of public spitting) are made. We are currently reaching a new limit on population density due to disease; there is a continuing problem with influenza, as viruses (e.g. bird flu) keep mutating and causing outbreaks; we have had outbreaks of Ebola; we do not have malaria under control and its territory is spreading due to global warming; HIV affects millions around the world; recently there was widespread concern about the Zika virus; drug-resistant TB is a growing problem in some cities. As people travel more, people in the west are getting more exposed to tropical diseases like yellow fever and the like. Diseases which we thought were under control, or even close to eliminated, like measles and polio, are making a comeback due to the refusal by some people to vaccinate their children.

The world is full of dangers. Maybe it is not such a good idea to shake people's hands, or kiss them on the cheek. Maybe, the next time that you notice that someone used the toilet and didn't wash their hands, you should say something.

There is also a very dangerous habit in some countries. In most of Europe, if you are sick, your doctor will write you off of work, partly to give you a chance to recover properly, and partly to ensure that you don't return to work while you are still infectious, and infect your colleagues or customers. In the USA, people often return to work while still ill and infectious, because they can lose their jobs if they take too much time off for sickness. I would argue that there is an economic imperative to change this behaviour, by ensuring people do not run the risk of being fired due to sickness, and by providing universal healthcare (so that people can afford to go to the doctor).