The flesh-eating New World screwworm has been detected in United States wildlife for the first time, the Department of Agriculture confirmed on Wednesday, marking an alarming breach in the nation’s defences against a parasite eradicated decades ago.
The USDA said the parasite was found in an elk in Pecos County, Texas, on a game ranch, reported after the animal was harvested by a hunter. Separately, New Mexico authorities confirmed a case in a beef cow in Otero County.
The Texas Animal Health Commission will modify a previously established infested zone, while the USDA and Texas Parks and Wildlife Department conduct additional surveillance. In New Mexico, officials established a 12.4-mile radius zone where animals must be inspected and treated before moving.
How it got here
Eradicated from the US decades ago, the screwworm has surged north from Central America through Mexico. Washington imposed a more than year-long ban on Mexican cattle imports to keep it out, resuming trade only in August at an Arizona port under a phased plan.
The import halt tightened American cattle supplies and helped push beef prices to record highs for consumers. Now the parasite is inside the border, and the economic stakes have risen sharply.
The fightback
The weapon is the sterile insect technique: overwhelming wild populations with infertile males to crash the breeding cycle. The USDA has been releasing sterile flies in Texas, the same method that eradicated the pest in the 1960s. Kenya’s Ebola containment effort shows how such operations work, and Reuters’ full report has the details of the Texas operation now on the front line.
Eradication took decades. Keeping it that way will take vigilance.
