As office workers all over Japan tuck into their lunchtime katsudon (pork cutlet with rice), I'm sure many of them joke about the H1N1 swine flu that threatened to become a pandemic (an epidemic affecting a large region). At the time of writing, the World Health Organization hasn't classed it as a pandemic; nor has it reached the shores of Japan to any great extent.
I imagine it's the natural assumption of many Japanese that swine flu is a foreign problem. It is not. All pig farms in the world play host to swine influenza viruses, and Japan's are no exception.
The story of the emergence of a swine flu virus that can be transmitted between humans is the story of the year so far — and it's all about natural selection. It's not over yet. Even the if the virus were to fizzle out now without becoming a full-blown pandemic, the fear is that it could return later in the year with a vengeance.