By Shelby Shank
Field Editor

The U.S. Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for a topical powder to prevent and treat New World screwworm (NWS) infestations in multiple species.

The authorization allows the use of Negasunt Powder, a topical powder containing coumaphos, propoxur and sulfanilamide topical powder.

Based on scientific evidence available, the FDA believes the product may be effective in preventing and treating NWS infestations in cattle, swine, goats, sheep, horses, donkeys, domestic hybrid equids such as mules, and captive wild, exotic and zoo mammals.

This product may not be used in domestic dogs or cats.

Distribution of Negasunt Powder will be tightly controlled.

Elanco US Inc., the drug sponsor, will supply the treatment exclusively to the U.S. Department of Agriculture (USDA). From there, it will be distributed only to authorized personnel, including federal, state and tribal agencies or individuals operating under their direction.

If NWS is detected in the U.S., the product may be used by or on the order of a licensed veterinarian in NWS-infested zones and adjacent surveillance zones as defined by the USDA in the NWS Response Playbook.

There are currently no NWS-infested zones in the U.S., but the closest case has been detected about 60 miles from the border.

Two active ingredients in Negasunt Powder, coumaphos and propoxur, can cause neurotoxicity. The EUA sets specific requirements to address this risk for people, animals and the environment.

FDA evaluated human food safety considerations and concluded that products from treated animals can be safe for consumption as long as all conditions outlined under the EUA are followed.

Animals treated with Negasunt Powder must not be slaughtered for human consumption within 28 days of the last treatment.

A milk discard time has not yet been established for this product, and it should not be used on animals producing milk for human consumption.

A withdrawal period has not been determined for pre-ruminating calves. Treated calves and calves born to treated cows must not be processed for veal.

Detailed product information about Negasunt Powder can be found in the fact sheet.

The authorization will remain in effect until it is revoked, or the U.S. Department of Health and Human Services Secretary terminates the declaration that the public health emergency presented by NWS justifies the emergency use authorization of animal drugs for NWS.

Negasunt Powder is one of four drugs approved by the FDA for emergency use treatment of NWS in livestock. The others include Ivermectin, Dectomax-CA1 and Exzolt Cattle-CA1.