Screwworm infestation spreads in Florida Keys

Officials say the infestation of screwworms is spreading in the Florida Keys.

On Tuesday, the U.S. Department of Agriculture and the Florida Department of Agriculture and Consumer Services announced they've detected screwworms in six areas west of Big Pine and No Name keys.

Earlier this month officials announced that anyone heading north from the Florida Keys with animals must stop at a checkpoint so agriculture officials can check for signs of New World screwworm. The screwworms are maggots that eat livestock and pets alive. Since July officials say they've killed about 60 Key deer.

Florida Agriculture Commissioner Adam Putnam said the Keys' isolation may help the infestation from spreading.

Officials say the additional detections aren't unexpected since enhanced surveillance is underway.