For a while, the cyclospora parasite seemed to be everywhere, with more than 22,000 confirmed and suspected cases across 15 states, including 517 hospitalizations and two deaths in Michigan. However, signs that the outbreak is slowing down have experts saying that lettuce is probably safe to eat again.
The Source of the Outbreak
Federal health authorities have linked the outbreak to iceberg lettuce sourced from central Mexico and distributed by Taylor Farms, including at Taco Bell restaurants. On July 17, Taylor Farms announced a recall of shredded iceberg lettuce and salad mixes with 'best if used by' dates through August 3, advising consumers to immediately discard any of the affected products. Grocery stores and restaurants are responsible for removing recalled items.
The Impact of the Recall
With the contaminated produce no longer available, the risk of cyclospora in terms of eating lettuce has been reduced, according to Kali Kniel, a professor of microbial food safety at the University of Delaware. However, consumers should still be vigilant about what they're eating, as there are two additional clusters of cyclosporiasis that officials are investigating. While a source has not been identified, officials in North Carolina are looking into parsley and cilantro, and an outbreak of salmonella tied to jalapeños has infected at least 345 people across 27 states.
The Incubation Period
Total cases of cyclosporiasis could continue to rise for weeks because of the lag time between when a person is exposed and when symptoms emerge, as well as delays related to seeking care, getting tested, and linking cases to contaminated products. On average, people exposed to cyclospora start to feel sick seven days after exposure, but symptoms can take up to 14 days to appear. Given the seven-day average incubation period and the recall in mid-July, most exposures likely happened in June and the first half of July.
The Michigan Outbreak
Michigan, which was hit hardest by the outbreak, has reported more than 12,000 cases since June. The state health department first identified lettuce and salad greens as a potential source of the outbreak on July 13 and advised consumers to purchase whole heads of lettuce rather than bagged products and to discard outer leaves and thoroughly wash inner leaves before eating. The cyclospora parasite clings to surfaces and crevices of raw produce and is resistant to common food sanitizers, making it tricky to get rid of.
The Importance of Vigilance
While the risk of cyclospora in terms of eating lettuce has been reduced, consumers should still be vigilant about what they're eating. As of August 6, the state health department said Michigan residents no longer need to avoid bagged salad mixes and may resume their usual food handling practices as new cyclosporiasis case reports and diarrhea-related emergency department visits are on the decline.
Conclusion
The cyclospora outbreak serves as a reminder of how complex food systems can increase the risk of foodborne illness. Buying whole lettuce is a safer bet, as it is easier to trace the source of an outbreak and ensure that produce is not contaminated. With the contaminated produce no longer available, experts say lettuce is probably safe to eat again, but vigilance is still advised.