Federal health officials in the United States have declared the nation’s largest recorded outbreak of cyclosporiasis over, following a multi-state incident linked to contaminated iceberg lettuce. The Centers for Disease Control and Prevention (CDC) confirmed that all recalled lettuce from Taylor Farms de Mexico has been removed from the market, ending the outbreak that infected 12,883 people across 21 states.

The outbreak, which peaked with over 1,000 infections reported in a single day, has seen a significant decline in cases, with fewer than two infections per day reported by August. The CDC reported a total of 19,595 laboratory-confirmed cases of cyclosporiasis between 1 May and 8 September, with 12,883 linked to the contaminated lettuce. Michigan was the hardest-hit state, reporting more than 14,000 cases and two deaths, followed by Illinois, Indiana, and Ohio.

The CDC stated that the best-by dates for all affected products have passed and they are no longer available in stores or restaurants. However, the Food and Drug Administration (FDA) noted that its investigation into the incident and other cyclospora clusters continues. The FDA emphasized the need for improved food safety practices, including better agricultural water management, worker hygiene, and supplier verification, to prevent future outbreaks.

The outbreak has raised questions about the effectiveness of US food safety controls, particularly regarding inspections of foreign food facilities. The FDA, which is responsible for inspecting over 19,000 international food sites annually, conducted its first inspection of the Mexican farm implicated in the outbreak only a month after the investigation began. The Trump administration’s scaling back of FoodNet, a program that tracks Cyclospora and other pathogens, and the delay of the Food Safety Modernization Act rule until 2028, have also drawn criticism.

The CDC continues to advise the public to wash hands and thoroughly rinse fresh produce before consumption, cutting away damaged areas and cooking produce to an internal temperature of at least 158F (70C). Symptoms of cyclosporiasis, which typically appear about a week after infection, include watery diarrhea, loss of appetite, weight loss, stomach cramps, bloating, and increased digestive gas. Less common symptoms include vomiting, body aches, headaches, and a low-grade fever.

The FDA’s ongoing investigation into food safety practices and the broader implications for US food safety controls remain areas of concern. The full results of laboratory analyses of samples collected from Mexican farms and processing facilities are still pending, leaving some uncertainty about the exact causes and long-term implications of the outbreak.