Daijiworld Media Network - Washington
Washington, Sep 12: US health authorities have declared the country's largest recorded multistate cyclosporiasis outbreak over after contaminated iceberg lettuce sickened thousands of people across the country, although the Food and Drug Administration (FDA) continues to investigate how the parasite entered the food supply.
The outbreak was linked to iceberg lettuce sourced from central Mexico by Taylor Farms de Mexico and resulted in one of the largest food recalls in recent years. The incident also raised concerns over food-safety controls for imported produce and affected consumer confidence in fresh vegetables and restaurant dining.
According to the latest federal figures cited by Reuters, 12,883 people across 21 states fell ill after consuming contaminated lettuce. The outbreak resulted in 570 hospitalisations and two deaths and accounted for more than half of the 19,595 laboratory-confirmed cyclosporiasis cases reported in the United States since May 1.
At the peak of the outbreak, more than 1,000 infections were reported in a single day. By August, the number of new infections had fallen to fewer than two per day on average, indicating a sharp decline in transmission after the contaminated products were removed from the market.
Cyclospora is a microscopic parasite that causes an intestinal infection known as cyclosporiasis. It is generally spread when food or water becomes contaminated with infected human faeces. Symptoms can include diarrhoea, loss of appetite, weight loss, abdominal pain, bloating, nausea and fatigue, while some infected people may have no symptoms.
The outbreak also affected the restaurant industry as concerns over contaminated produce prompted some consumers to avoid raw vegetables and dining out. Restaurant chains including Taco Bell, Sweetgreen and Chipotle faced pressure as customers became more cautious about food containing leafy greens.
Food safety experts said the outbreak exposed gaps in the ability to rapidly identify and contain parasite-related outbreaks. Donald Schaffner, a professor and extension specialist in food science at Rutgers University, said better strain-tracking tools and sustained funding for parasite research would be needed to prevent similar incidents.
The FDA said it was confident that all recalled iceberg lettuce connected to the outbreak had been removed from the market. The CDC has also said the best-by dates of products linked to the outbreak had passed, meaning the recalled lettuce should no longer be available in stores or restaurants.
Taylor Farms recalled all iceberg lettuce sourced from central Mexico on July 17 after federal investigators traced the outbreak to its Mexican operations. FDA officials subsequently conducted inspections and collected samples from lettuce farms and the processing facility in Mexico. Testing and analysis remain part of the continuing FDA investigation.
“Our facility in central Mexico remains closed while the investigations by the FDA, our team, and independent experts are being completed,” a Taylor Farms spokesperson told Reuters.
The FDA said it would continue working with US, Mexican and state authorities as it investigates the source of the contamination and develops measures to prevent similar outbreaks.
Michigan was among the hardest-hit states, with more than 14,000 cases and the two deaths linked to the outbreak, according to federal and state officials. Ohio and Missouri also recorded thousands of infections associated with contaminated lettuce from Taylor Farms.
Michigan's unusually high case numbers were partly attributed to a backlog of reports processed in August, highlighting the strain placed on local and state public-health systems during the outbreak. Reuters previously reported that health departments had to redirect staff from routine activities, including vaccinations and restaurant inspections, to investigate cases and trace possible sources.
The outbreak has renewed calls for stronger food-safety surveillance and faster systems to trace contaminated produce. Experts have warned that the US public-health system faces challenges from staffing shortages, limited resources and the difficulty of tracing Cyclospora, which has a relatively long incubation period.
Before 2026, the largest recorded US cyclosporiasis season occurred in 2019, when about 4,700 illnesses were documented nationwide. The 2026 outbreak therefore represents an unprecedented scale for the disease in the United States.
While the specific multistate outbreak has now been declared over, the FDA's investigation continues, meaning authorities have yet to establish exactly how Cyclospora contaminated the lettuce and entered the food supply.