There was an interesting article in the Sydney Morning Herald on 2008.05.08
which discusses the importance of not leaving food out too long.
There are lots of statistics which show that food poisoning is much more prevalent than most people assume. In fact, many cases of food poisoning are likely shrugged off as upset stomachs or stomach bugs not realizing that mishandling of food was the cause. This article however states that there are 5 million cases of food poisoning in Australia every year. That is pretty amazing considering the entire population is only around 20 million.
I checked with the source sited in the article and indeed the Food Safety Information Council states that there are 5.4 million cases of food borne disease a year.
I then found the original source of the information, the Australian Department of Health and Aging's "Foodborne Illness in Australia" report of 2000.
(** PDF file **)
It turns out to be even more interesting. This survey estimates 17.2 million cases of gastroenteritis a year, of which 5.4 million are thought to result from contaminated food. The definition is broad enough to cover many cases which do not result in a visit to the doctor, but these are still pretty surprising statistics considering the population of the country.
I might try looking up the numbers for Japan, but nevertheless think it would be hard to directly compare the two (the survey methods would likely be significantly different).
In addition to being a measure of how important it is to handle food properly, this also makes a case for consuming probiotics - the easiest way I know of to avoid gastrointestinal problems. Most probiotics sold by major dairy food companies have scientific data backing up their claims of effectiveness. Probiotics will not prevent gastrointestinal problems but there is a great deal if evidence that they reduce occurrence of such problems.
In Japan, probiotics along with prebiotics make up the largest category of FOSHU foods - that is foods with government approved health claims. In fact, the majority of yogurts sold in Japan have probiotic strains added, not just starter strains.