Childhood Illnesses: Sources of Food Poisoning

The most common causes of food poisoning are the bacteria Campylobacter, Salmonella, E. coli and a group of viruses called calicivirus (also known as the Norwalk and Norwalk-like viruses).

Raw foods of animal origin are the most likely to be contaminated: raw meat and poultry, raw eggs, unpasteurized milk and raw shellfish. Because filter-feeding shellfish strain microbes from the sea over many months, they're more likely to be contaminated.

Foods that mingle the products of many individual animals are particularly hazardous because one contaminated animal can contaminate the whole batch.

Fruits and vegetables consumed raw are a concern, as well. The quality of the water used for washing and chilling the produce after it is harvested is critical. Unpasteurized fruit juice can be unsafe if the fruit used to make it was contaminated.