President Donald Trump has threatened to impose tariffs on Mexico over a major outbreak of cyclosporiasis, a parasite that causes explosive diarrhea, potentially linked to lettuce grown there.
"I think what we are going to do is put a major tariff on Mexico because of the lettuce," Trump said during a press briefing at the White House.
Trump spoke as cases of the parasite soared to nearly 11,000 across 41 states, leaving public health officials scrambling to find the cause. He also repeated his threat to impose major tariffs on Canada after wildfires there left much of the northern United States covered in toxic smoke.
Health officials have suggested the cases may be linked to shredded iceberg lettuce from Taylor Farms that was sent to Taco Bell restaurants in nine states. Illinois, Kansas, Oklahoma and Pennsylvania are now suggested to be affected, alongside Indiana, Kentucky, Michigan, Ohio and West Virginia.
Tests on lettuce from Taylor Farms' manufacturing facility in Mexico returned a false positive, but a voluntary recall of the products remains in place. The company temporarily closed its Central Mexico site on Thursday.
Officials respond to the outbreak
Health and Human Services Secretary Robert F Kennedy Jr said on Tuesday that the outbreak was "under control." The Food and Drug Administration said Wednesday it was tracking a separate outbreak of the parasite that has sickened 72 people, in a cluster distinct from the one sickening thousands and potentially tied to the same lettuce.
The agency gave no further details on the new cluster, including the location of the patients or the potential source of their illness. Health officials are now recommending people wash their hands and any fresh produce thoroughly before preparing food, and cook food to at least 158F (70C) to kill the parasite, since washing alone is not guaranteed to remove it.
How the parasite spreads
Cyclosporiasis spreads when people eat food or drink water contaminated with human feces. According to the Centers for Disease Control and Prevention, it is unlikely to spread directly from person to person, because it takes one to two weeks for the parasite to become infectious after passing into the environment.
Dr Luis Ostrosky, an infectious diseases expert at UTHealth Houston, said cyclosporiasis spreads via the fecal-oral route, where fecal particles containing the parasite are passed to the mouth. He said it typically does not transmit from person to person and does not spread the way norovirus or the flu does, and that it takes one to two weeks after the parasite passes in a bowel movement to become infectious, with symptoms appearing days to a few weeks after exposure.
Case numbers and hospitalizations
The CDC has recorded nearly 11,000 suspected or confirmed cases this year, the most since 2019, when an outbreak was linked to basil. The agency has confirmed 4,100 cases and is investigating 7,400 others across 41 states. There have been 308 hospitalizations, but no deaths have been reported.
Michigan is recording the most cases, at up to 2,100, followed by Illinois, Kentucky and Texas, each with up to 160 cases. The parasite, cyclospora, causes a gastrointestinal illness with symptoms including watery and explosive diarrhea, cramping and fever. Patients become sick within a week of infection, which can make it difficult to identify the source, and some feel they are improving before symptoms suddenly worsen again.
Taylor Farms and Taco Bell response
A spokesman for Taylor Farms said Thursday the company had commissioned independent experts to conduct a top-to-bottom review of food safety processes and protocols at its Central Mexico facility, and continues to work with health authorities, customers and independent farming partners to address the issue.
Taco Bell has removed the lettuce from its supply chain. A spokesman said last week that Taco Bell had taken precautionary action and encouraged all relevant restaurants, retailers and foodservice operators to do the same.
