- The New World screwworm is fly larvae that infects the living tissue of a warm blooded animal.
- If it gets to the United States, the impacts could be devastating to livestock producers and others.
- It is not yet in the United States, but is in Mexico — leading to worries it could arrive here. $165 million in emergency funding is being spent to stop its spread.
The U.S. Department of Agriculture is extremely worried about the arrival in the U.S. of a fly larvae called the New World screwworm that infests the living tissue of warm-blooded animals, causing infection.
As a result, the agency’s Animal and Plant Health Inspection Service, or APHIS, plans to spend $165 million in emergency funding to protect U.S. livestock and other animals.
“The current outbreaks in Central America demonstrate the need for USDA to increase its investment in NWS eradication and prevention,” said Jenny Lester Moffitt, the agency’s undersecretary for marketing and regulatory programs.
“If NWS were to spread to the United States, it would result in significant economic losses and threats to animal health and welfare. This funding will allow for a coordinated emergency response to control the outbreak and prevent NWS from spreading to the United States,” she added.
The agency says the pest is a serious threat. They burrow into the flesh of a living animal and cause serious, often deadly damage. They can infest livestock, pets, wildlife, occasionally birds, and in rare cases, people. That is why the U.S. does not want it here.
The state veterinarian who works for the Utah Department of Agriculture and Food, Dr. Amanda Price, said the United States has enacted restrictions on imports of live cattle and bison from areas where the pest has infiltrated because of the risk. In addition, horses coming into the country have to be quarantined for seven days and have treatment. Dogs coming in from impacted areas also have to have a health certificate within five days of entry into the country.
“They have actually found it in people before. It’s one of those things that you would probably notice pretty quickly, but where dogs and cats can’t talk, it is one of those things that might go undetected,” she said.
Where is the New World screwworm right now?
Over the last two years, the larvae has spread throughout Panama and into Costa Rica, Nicaragua, Honduras and Guatemala. In late November, the chief veterinary officer of Mexico notified U.S. officials of a positive detection in southern Mexico, near the Guatemalan border.
APHIS is working with partners in Mexico and Central America to stop the spread of the pest into the United States and is asking all producers along the southern border to watch their livestock and pets for signs of NWS and immediately report potential cases to their local veterinarian, State Veterinarian’s Office, or APHIS Veterinary Services.
The only way to eradicate the pest is through a sterile insect technique. With this method, sterile flies are released into an area where a known population has become established. The sterile male screwworm fly mates with fertile female screwworm fly, causing the population of screwworm flies to decrease until it eventually dies out. But Price added it is a process that takes time.
The pest was eradicated at a cost of $800 million 30 years ago in Central America, Mexico and the United States. Price said she is not overly concerned now because of how swiftly the the U.S. Department of Agriculture has reacted, but it is a cautionary tale to be proactive.
Groups like the Wildlife Conservation Society believe that illegal cattle trafficking which bypasses important health controls is in part fueling the pest’s new emergence.
“This swift spread endangers millions of animals and threatens the livelihoods of ranchers across the region. By bypassing sanitary controls, often with stressed, undernourished, and injured livestock, cattle smuggling creates the ideal conditions for transboundary transmission of diseases, including brucellosis, tuberculosis, and parasites such as the screwworm,” the group said.
APHIS is asking all producers along the southern border to watch their livestock and pets for signs of the pest and immediately report potential cases to their local veterinarian, State Veterinarian’s Office, or APHIS Veterinary Services.