Topline
As a growing cyclosporiasis outbreak has sickened thousands across the U.S., social media has filled with widespread confusion and speculation about how the parasite spreads, what foods are safe to eat and how to avoid infection—but many of the most widely shared rumors are false and could do more harm than good.
A women washes lettuce.
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Key Facts
Raspberries aren’t safe. False. Doctors and infectious disease experts initially recommended temporarily avoiding fresh raspberries because they’re difficult to wash and have been linked to previous cyclosporiasis outbreaks, but there’s so far no indication raspberries are involved in the current outbreak.
Frozen produce is a safe option. True. Frozen vegetables are largely safe from cyclospora because most commercial facilities wash and blanch (briefly dip in boiling water) them before they’re packaged, killing the parasite. The same is true for canned produce—the commercial canning process relies on high heat to seal food, largely eliminating cyclosporiasis risk.
It can spread from person to person. False. Cyclospora spreads when people eat food or drink water that was contaminated with feces, and it takes at least one to two weeks of living outside the body to become infectious, making direct person-to-person transmission extremely unlikely, per the Centers for Disease Control and Prevention.
All lettuce is contaminated. False. Investigators have traced the ongoing outbreak to a specific supply chain that reportedly involves Taylor Farms in Mexico. The contaminated shredded iceberg lettuce was served at Taco Bell restaurants in several states and the CDC is still working to find where else the lettuce may have been distributed.
Washing produce doesn’t help. False. Washing fruits and vegetables won’t kill the cyclospora parasite and may not remove it entirely because it clings tightly to produce, but public health agencies still recommend washing fruits and vegetables and say it can reduce further contamination.
It’s impossible to kill cyclospora. False. Heating to produce to 158 degrees Fahrenheit, or 70 degrees Celsius, will kill it.
Fresh fruits and vegetables are no longer safe. False. Infectious disease experts continue to recommend eating produce, especially items that can be peeled, and advise taking extra care with foods that are commonly eaten raw or difficult to wash thoroughly.
The government is responsible for the outbreak. Unclear. The federal government last year rolled back FoodNet, the active surveillance network it had run with the Food and Drug Administration, the Department of Agriculture and 10 state health departments since 1995. The roll back made tracking of cyclospora optional, instead of required. That change in policy may have allowed the parasite to spread unchecked for longer than if funding hadn’t been cut, but it’s too hard to say if it played a major role in the outbreak. FoodNet also never monitored cyclospora in Michigan, where the outbreak has been the most prevalent.
Key background
Thousands of people have been sickened since May with cyclosporiasis, a gastrointestinal illness since dubbed the “explosive diarrhea parasite.” A majority of infections are in Michigan, which alone is reporting 4,312 cases and 102 hospitalizations, but people in 34 states have been impacted. Fear quickly spread across the country as cases climbed without any confirmation of where they were coming from, until the CDC on Thursday confirmed the link with the Taco Bell restaurants. The chain has since stopped serving the lettuce in the impacted states.
WHAT WE DON’T KNOW
Where else cyclosporiasis could be coming from. The CDC says more than 1,600 of the estimated 7,000 people sickened in the outbreak reported eating at the Taco Bell restaurants, but the other roughly 3,400 patients didn’t. Since the illness doesn’t spread person-to-person, they also ingested something infected with the cyclospora parasite. The FDA is working to find out where else the contaminated lettuce may have been distributed, but Taylor Farms sells products in tens of thousands of grocery stores and to thousands of restaurant locations across the country, making tracing difficult.