Missouri has confirmed 216 cases of cyclosporiasis, up from 43 reported last week, according to the Missouri Department of Health and Senior Services.
The department updated the case count Sunday, marking a fivefold increase as health officials continue tracking the outbreak.
State Epidemiologist Nathan Koffarnus said officials expected the number of infections to rise as awareness of the outbreak increases.
"More people that maybe have the disease are sitting at home with symptoms that otherwise would just kind of wait it out, they're more likely to seek out medical care," Koffarnus said. "Their doctors are more likely to order tests for cyclosporiasis. This is probably not generally at the top of their list of agents to look for. And so it's understandable that we get more records."
Koffarnus said the state is not seeing a dangerous level of infections but is closely monitoring the outbreak.
Boone County had confirmed 37 cases as of Monday morning, up from 13 last week, according to Boone County Health Department public information specialist Austin Krohn.
The Centers for Disease Control and Prevention said investigators have linked the multistate outbreak to packaged iceberg lettuce produced by Taylor Farms de Mexico. The company has recalled affected products with use-by dates from July 18 through Aug. 3, 2026. However, the U.S. Food and Drug Administration is now listing a sample taken from Taylor Farms on Saturday as a false positive result, rather than as a possible source of the contamination now recorded in dozens of states.
Cyclosporiasis is an intestinal illness caused by the parasite Cyclospora cayetanensis. Symptoms can include prolonged diarrhea, loss of appetite, weight loss, stomach cramps, bloating, nausea and fatigue.
The illness is typically spread through contaminated fresh produce or water and does not spread directly from person to person.
