US FDA says it is investigating another cyclosporiasis outbreak

The US FDA has said it is investigating a new outbreak of cyclosporiasis, with 72 cases tied to an as-yet-unidentified source.

The agency’s announcement on Wednesday adds to the growing number of cyclosporiasis cases reported across the US Midwest, including Michigan and four other states.

The Food and Drug Administration said it has initiated a traceback to identify the source of the latest outbreak.

Cyclosporiasis is an intestinal illness caused by the Cyclospora parasite. People can become infected after eating or drinking contaminated food or water, and symptoms can include diarrhea, stomach cramps, nausea, and fatigue.

The CDC has identified 4,173 laboratory-confirmed, domestically acquired cyclosporiasis cases in the United States since May 1 and is investigating more than 7,400 additional reported infections that have yet to be laboratory confirmed, many of them in Michigan and Ohio. The figures come as Michigan has reported 7,171 cases so far this year, while Ohio has also recorded a sharp rise in infections.

Regulators have linked the broader spread in the Midwest, the largest foodborne illness outbreak in the US in recent years, to a Taylor Farms plant in Mexico.

On July 17, Taylor Farms recalled iceberg lettuce sourced from central Mexico. The recall includes lettuce sold in retail stores, served in restaurants and distributed to food service customers.

However, Mexico said on Tuesday there was no evidence yet to suggest that lettuce sourced from it caused the outbreak in the US

The outbreak has also affected restaurant operators. Shares of Yum Brands fell nearly 10% last week after reports linked Taco Bell to the spread of the illness, although analysts have said the impact on the chain’s sales is unlikely to cause lasting damage. Taco Bell has since stopped using lettuce supplied by Taylor Farms.

Cyclospora infections typically spike in the US during the spring and summer months as warmer climates help the parasite thrive, often leading to multistate investigations by health authorities.