US Declares End to Record-Breaking Cyclosporiasis Outbreak

US health officials have announced the conclusion of the country’s largest ever recorded outbreak of cyclosporiasis, an illness linked to contaminated iceberg lettuce that affected nearly 13,000 people across 21 states.

The Centers for Disease Control and Prevention (CDC) said on Friday it was confident that all recalled lettuce connected to the outbreak had been cleared from the market. The agency reported 12,883 confirmed cases, with 570 hospitalisations and two deaths.

Cyclosporiasis symptoms typically emerge around a week after consuming contaminated food or water, though onset can range from two days to two weeks. The illness commonly causes persistent watery diarrhoea, along with symptoms such as appetite loss, weight loss, cramping, bloating, gas, nausea and fatigue.

Investigators traced the outbreak to iceberg lettuce grown in central Mexico and supplied by Taylor Farms de Mexico, which recalled all iceberg lettuce from that region on 17 July. The problem was first linked to lettuce served at Taco Bell outlets before authorities identified Taylor Farms, a major supplier to restaurants and retailers throughout the US, as the source.

At the outbreak’s height, more than 1,000 new infections were reported in a single day. By August, the CDC said the daily rate of new cases had dropped to fewer than two on average.

The outbreak formed part of a broader nationwide surge in cyclosporiasis this year. Since 1 May, almost 20,000 laboratory-confirmed cases have been reported in the US — more than 16 times the total for the same period last year. The previous highest annual total was in 2019, when about 4,700 cases were recorded.