The cyclospora outbreak linked to more than 12,000 cases this summer has ended, the Centers for Disease Control and Prevention said Friday.

The CDC said in a statement Friday the contaminated iceberg lettuce associated with the outbreak, which had spanned 21 states, is no longer available in stores or restaurants, and that the number of recent infections has fallen significantly.

In August, fewer than two infections occurred per day on average, compared with more than 1,000 daily infections during the peak of the outbreak, the CDC said.

Health officials had linked the outbreak to processed iceberg lettuce sourced from central Mexico by Taylor Farms de Mexico, which recalled the product in mid-July.

The Food and Drug Administration is continuing its investigation of how any contamination occurred, according to the CDC.