this is all I could find on Google:
n some cases, food poisoning may take weeks before symptoms start to appear. Hepatitis A, for example, doesn't appear for almost four weeks; it can be found in shellfish, produce and similar raw foods. Giardia lamblia, which appears in raw vegetables, manifests after 7 to 14 days. These origins of food poisoning can be difficult to pinpoint sometimes because of the length of time between eating the food and e
Read more: How Long Does it Take for Food Poisoning to Take Effect? | eHow.com
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