A rare case of travel-related New World screwworms has been identified in Maryland, a US Department of Health and Human Services spokesman, said it had been identified.
The U.S. Centers for Disease Control and Prevention and the Maryland Department of Health are investigating a case of carnivorous parasites that was confirmed on August 4th, said Andrew Nixon, a spokesman for the HHS.
“This is the first human case of New World screwworm (fly larvae parasite invasion) related to travel from countries affected by the outbreak identified in the US,” Nixon said in an email. “Rising risks to public health in the United States right now from this implementation are very low.”
A spokesman for the Maryland Department of Health said in a statement that Maryland residents have recovered from the infection and “there are no indications of transmission to other individuals or animals.”
New World Screwworm Outbreaks – The shape of the fly larvae, a type of nest and slowly eats in the wounds of warm-blooded animals, has spread to Central America since early 2023, with invasions recorded in Belize, Costa Rica, El Salvador, Guatemala, Honduras, Mexico, Nicaragua and Panama. Fry reached southern Mexico late last year, raising concerns among US agricultural industry officials, and this year caused the closure of ports of cattle, horses and bison trading in the border area.
Parasites pose a major threat to animal populations and food supply. The US largely eradicated New World screwworm populations by breeding sterile male species in the 1960s and 1970s, dispersing them from planes and mating with wild female fly. This month, the USDA announced that it would build a fly production facility at Moore Air Force Base in Edinburg, Texas. It will work in facilities in Panama and Mexico, according to the USDA.
“The construction of a domestic sterile fly production facility ensures that the United States will continue to lead the way in the fight against this devastating pest,” USDA Secretary Brook Rollins said this month. “If ranchers are overrunning with foreign pests, we can’t feed ourselves.”
The USDA said it would offer up to $100 million for additional technologies, including traps, lures and techniques that could enhance flies production. The agency also said it would hire a mounted patrol officer known as “tick riders” for surveillance and train screw bug detection dogs to search for outbreaks among livestock.
This month, HHS issued an emergency declaration, allowing the US Food and Drug Administration to increase the flexibility of animal drugs to treat and prevent the invasion of new world screwworms. Although there are no FDA-approved drugs for New World screwworms in the United States, this declaration allows agencies to approve drugs for emergency permits.
The New World Screwworm is a parasitic larvae of the species of metallic blue blowfly called Cochliomyia hominivorax. Unlike all other blowflies native to the Western Hemisphere, New World Screwworms feed the meat of live animals rather than dead animals. Dr. Philip Kaufman, professor and director of the Department of Entomology at Texas A&M University, previously told CNN.
Carnivorous maggots go for most warm-blooded animals, including horses and cows. It can also infect pets and humans.
“After mating, the female fly finds a living host, lands on the wound, lays up to 200-300 eggs,” Kaufmann explained. “After 12-24 hours, all those eggs will hatch and soon begin to burrow into the animal’s tissue, creating a very large wound.”
Treatment of infected cows often includes washing, preservative treatment, and wound covering. If left untreated, the flies can kill the animal within a week or two, and spread to others.
“We’ve seen a lot of people who have had a lot of trouble with their health,” said Daniel Griffin, an infectious disease expert at Columbia University. “And when the eggs hatch, the maggots dig a hole and they quickly turn the living tissue into Swiss cheese.”
