For Taco Bell, the worst sales hit came the weekend of July 18, just after the chain announced it was pulling potentially contaminated lettuce from stores. The FDA and CDC have tied the outbreak to lettuce from Taylor Farms, including shredded lettuce from the supplier served at Taco Bell restaurants in at least nine states. The CDC is also investigating case clusters unrelated to the Taco Bell outbreak — which has sickened at least 1,947 people — as national confirmed and suspected cyclosporiasis cases near 20,000. The extent of the epidemic makes it likely that consumers have been sickened by produce from sources other than Taco Bell. Taco Bell gives rewards members weekly offers called Tuesday drops.