U.S. health officials have granted the Food and Drug Administration (FDA) the authority to quickly approve the use of animal drugs to prevent or treat screwworm infestations in livestock.
The decision allows veterinarians and farmers to use drugs that may not be formally approved or are available in other countries, the Department of Health and Human Services (HHS) announced.
The Threat of Screwworm to Livestock and Food Supply
Screwworm, a parasitic fly that infests livestock, poses a significant threat to the nation’s cattle herds. The pest, which feeds on living animals, has not been reported in the U.S. for decades.
However, the discovery of the fly in Mexico last month, near the U.S. border, has raised concerns that it could spread into the U.S., potentially harming cattle populations and driving up beef prices, which are already at record highs.
Emergency Measures and Drug Approvals
The best method to control screwworm infestations is by breeding sterile flies to reduce the mating population. However, experts say it will take time to build the necessary facilities to produce enough sterile flies to manage the situation effectively.
In the meantime, cattle ranchers may need access to screwworm drugs, but no FDA-approved drugs for the pest are currently available in the U.S.
In response, the FDA has been authorized to issue Emergency Use Authorizations (EUAs) for animal drugs that are not formally approved to treat screwworm. This allows for quicker access to drugs, bypassing the standard, lengthy approval process.
Risk to U.S. Animal Populations and the Food Supply
While the risk to human health remains low, the potential threat to animal populations and the food supply chain is significant. The FDA emphasized that proactive action was necessary to address the possible future spread of screwworm.
The agency’s ability to issue EUAs for unapproved drugs is based on the urgency of the situation and the lack of alternatives to combat the pest.
FDA’s Assessment of Drugs for Screwworm
FDA officials are reviewing products that are approved for other uses, including those from international markets where screwworm has been endemic. They are considering whether these products can be repurposed to fight the pest.
The FDA has also been in discussions with drug companies to bring appropriate treatments to the U.S.
Calls for Ivermectin Use in Livestock
In May, the cattle producer group R-CALF USA requested that the FDA allow ranchers to feed ivermectin to livestock as a precautionary measure against screwworm infestations. Ivermectin, an anti-parasite drug, has been successfully used by the USDA to control other livestock pests, such as cattle fever ticks.
Investment in Sterile Fly Production
To address the long-term challenge of screwworm infestations, the USDA announced it would invest up to $750 million in building a facility in Texas to produce sterile flies. However, this facility is expected to take two to three years to become operational.
