New World screwworm: uncommon human case recognized in United States after journey from El Salvador

A uncommon case of travel-related New World screwworm was recognized in Maryland in a affected person who traveled from El Salvador, a spokesman from the US Department of Health and Human Services mentioned.

The US Centers for Disease Control and Prevention and the Maryland Department of Health are investigating the case of the flesh-eating parasite, which was confirmed on August 4, HHS spokesman Andrew Nixon mentioned. No extra details about the affected person’s situation was made accessible.

“This is the first human case of travel-associated New World screwworm myiasis (parasitic infestation of fly larvae) from an outbreak-affected country identified in the United States,” Nixon mentioned in an e-mail. “Currently, the risk to public health in the United States from this introduction is very low.”

An outbreak of New World screwworms — the larval type of a kind of fly that’s recognized to nest within the wounds of warm-blooded animals and slowly eat them alive — has been spreading across Central America since early 2023, with infestations recorded in Belize, Costa Rica, El Salvador, Guatemala, Honduras, Mexico, Nicaragua and Panama. The fly reached southern Mexico late final 12 months, sparking concern amongst US agricultural business officers and triggering closures of border-area cattle, horse and bison buying and selling ports this 12 months.

The parasite poses a major menace to animal populations and the meals provide. The United States principally eradicated New World screwworm populations within the Sixties and Seventies by breeding sterilized males of the species and dispersing them from planes to mate with wild feminine flies. This month, the US Department of Agriculture announced it might assemble a fly manufacturing facility in Edinburg, Texas, at Moore Air Force Base, that would produce as much as 300 million sterile flies per week. It will work with services in Panama and Mexico, USDA mentioned.

“The construction of a domestic sterile fly production facility will ensure the United States continues to lead the way in combating this devastating pest,” USDA Secretary Brooke Rollins mentioned this month. “If our ranchers are overrun by foreign pests, then we cannot feed ourselves.”

USDA mentioned it’s going to additionally present as much as $100 million for added applied sciences, together with traps and lures, therapeutics and methods that would bolster fly manufacturing. USDA additionally mentioned it might make use of mounted patrol officers often known as “Tick Riders” for surveillance and would prepare screwworm detection canines to seek for outbreaks amongst livestock.

This month, HHS additionally issued an emergency declaration that allowed the US Food and Drug Administration extra flexibility for animal medication to deal with and prevention New World screwworm infestations. There aren’t any FDA-approved medication for New World screwworm within the United States, however the declaration permits the company to authorize medication for emergency authorization.

New World screwworms are the parasitic larva of a metallic blue blow fly species known as Cochliomyia hominivorax. Unlike all different blow flies native to the Western Hemisphere, the New World screwworm feeds on the flesh of residing animals, quite than lifeless ones, Dr. Phillip Kaufman, a professor and head of the division of entomology at Texas A&M University, beforehand informed CNN.

The flesh-eating maggots go for many warm-blooded animals, together with horses and cows. It also can infect pets and people.

“After mating, the female fly finds a living host, lands on its wound, and will lay up to 200 to 300 eggs,” Kaufman defined. “After 12 to 24 hours, those eggs all hatch, and they immediately start burrowing and feeding on the tissue of that animal, causing very, very large wounds to form.”

Treatment for infested cattle typically entails cleansing, antiseptic remedy and coverings for wounds. If left untreated, the flies can kill an animal in a matter of 1 to 2 weeks and unfold to others.