Beware of Foil-Wrapped Potatoes.

Botulism is usually associated with improperly preserved food, but this outbreak -- the largest in the U.S. in the last 20 years -- stemmed from baked potatoes.

Twenty-eight people became ill with the classic neurologic symptoms of botulism after dining at a Greek restaurant in El Paso, Texas, in April 1994, and two others were found to have asymptomatic disease. A retrospective case-control study implicated two mashed potato-based appetizer dips, and botulinum toxin was later found in leftover samples of both. On inspection, the restaurant was compliant with all state health code standards. However, potatoes used in the dips were foil-wrapped before baking, then stored in foil at room temperature for a prolonged period before use. Experimen…