WASHINGTON, D.C. — U.S. health authorities are investigating a multistate Cyclospora outbreak linked to contaminated iceberg lettuce as the number of confirmed infections continues to rise.

The CDC's latest update says 1,947 people across nine states have been confirmed infected in the outbreak associated with exposure to Taco Bell. At least 98 people have been hospitalized, while no deaths have been reported. Illnesses began June 22 and have continued to be reported through July 20.

Investigators say epidemiologic and traceback evidence points to iceberg lettuce from Taylor Farms de Mexico as the contaminated ingredient. The company recalled iceberg lettuce sourced from central Mexico on July 17, with recalled products distributed to retailers, restaurants and food-service customers.

The outbreak has expanded from the original five states to nine states, with Illinois, Kansas, Oklahoma and Pennsylvania added to the investigation. Health officials warn that the true number of infections could be higher because some people recover without seeking medical care or are never tested.

The wider national picture is also drawing attention. Separately from this specific outbreak, the CDC reported 4,173 laboratory-confirmed domestic Cyclospora cases in 41 states between May 1 and July 20, along with 308 hospitalizations and no deaths. The agency is also aware of more than 7,400 additional reports that have not yet been laboratory confirmed.

CDC, FDA and state health officials continue to investigate the outbreak and trace potentially contaminated food products. The latest development underscores the importance of food-safety surveillance, rapid outbreak detection and public-health coordination as officials work to prevent additional infections.