You may have heard of some of these bugs...
E.
coli, Salmonella, Listeria, Shigella and
Campylobacter.
All are quite nasty and there are many others like them. They have three things
in common: they are very small (you need a powerful microscope to see them); they
make lots of copies of themselves very quickly; they are everywhere. You find
E. coli in poorly cooked ham and other meats. It causes 20 000 cases of
food poisoning and kills 200-500 people in the USA every year. The Salmonella
bug turns up in as many as three quarters of all chickens. Campylobacter
turns up in chickens too and also in raw milk [1]. Cholera used to cause huge
epidemics and killed millions of people. You find it in contaminated seafood and
water. Cholera
still infects 5-7 million people and kills around 100,000 of those infected every
year. The disease starts, almost always in poor countries, where the water supplies
are not clean or people with no running water at all are forced to drink from
polluted rivers.
Yet even in rich countries like the United States which has clean water, the Centers
for Disease Control and Prevention reckon that foodborne diseases cause approximately
76 million illnesses, 325,000 hospitalizations, and 5,000 deaths every year [1].
So don't be surprised if you end up with a painful tummy if you slice up food
you're later going to eat raw with a knife you just used to cut up a contaminated
piece of meat. This is called cross contamination. And lots of that clean-looking
meat you buy in neat packs from the supermarket will contain these bacteria. 'Clean-looking'
doesn't mean 'bug-free'!
But with just a little care, you can avoid trouble. In most
cases, you can destroy these bugs by proper cooking and generally being clean
in the kitchen including washing your hands before touching food. Kitchen dishcloths
and sponges are often stuffed with bugs.
They love it: warm, wet and with loads of old food to chomp up. Oddly enough,
wooden chopping boards are much more bug-free than plastic ones [2].
The bottom line is to
- drink water you know is clean and
- eat food you know is fresh - and freshly prepared with clean knives and
things
Find out more about the food poisoning bugs on the Union of Concerned Scientists'
website.
1. Food-Related
Illness and Death in the United States, CDC (2003)
2.
Science News, 14/9/96, 172-3