The lettuce scare bug

The lettuce scare bug

The parasite that emptied lettuce bins at Taco Bell cannot be passed from one person to the next.

Cyclospora cayetanensis is a microscopic parasite spread only by swallowing contaminated food or water, according to the CDC. The parasite must sit in a warm, moist spot for one to two weeks to mature. That is why it rarely spreads person to person. Rinsing produce does not reliably remove it. Freezing does not kill it; cooking heat does.

Watery diarrhea, cramps, nausea and fatigue show up about a week after exposure, according to the CDC. The treatment is one specific antibiotic, trimethoprim-sulfamethoxazole.