( File photo )

The number of lab-verified cases in a cyclospora outbreak linked to Fresh Express salads sold at McDonald’s restaurants continues to mount.

The Food and Drug Administration and the Centers for Disease Control and Prevention are working with local and state health officials in the states affected by the parasites.

As of Aug. 24, the FDA reported there are 507 cases related to the cyclosporiasis outbreak, according to the FDA’s latest update on the outbreak. That’s an increase of 31 cases in a week.

As in previous updates, the FDA reported that the “investigation is ongoing and the FDA is currently reviewing distribution and supplier information for romaine and carrots.”