A multistate outbreak of cyclosporiasis has sickened over 1,900 people across nine states and continues to expand, health officials report. The infection stems from contaminated iceberg lettuce, marking a significant public health concern for consumers nationwide.

Cyclospora cayetanensis, a parasitic protozoan, causes cyclosporiasis, a gastrointestinal illness that produces watery diarrhea, abdominal cramps, nausea, and fatigue. Symptoms typically emerge 7 to 10 days after exposure. The outbreak traces directly to contaminated iceberg lettuce, a staple vegetable in American households and restaurants.

The expanding geographic footprint reveals the complexity of modern food supply chains. Iceberg lettuce distributed from a single source or region can reach multiple states rapidly, spreading infection across state lines before contamination becomes apparent. Public health agencies have identified nine affected states so far, though the number continues to grow as surveillance systems detect additional cases.

Officials at the Centers for Disease Control and Prevention (CDC) and state health departments work to trace the source of contamination and identify the specific lettuce producer or distributor responsible. Cyclospora typically contaminates produce through water exposure during growing or washing stages, often linked to fecal contamination in agricultural regions with poor sanitation infrastructure.

Most cases resolve without treatment within several weeks, though infection causes significant discomfort and can lead to complications in immunocompromised individuals. Healthcare providers treat severe cases with antibiotics like trimethoprim-sulfamethoxazole.

The outbreak underscores persistent vulnerabilities in produce safety systems. Despite regulations enacted after previous foodborne illness incidents, contamination events continue. Consumers face challenges distinguishing safe lettuce from potentially hazardous products once produce enters the market without clear origin labeling.

Public health authorities recommend washing lettuce thoroughly and