New World screwworm cases in Southern New Mexico have tripled in recent days as the parasitic fly continues to spread to new parts of the state, data from the U.S. Department of Agriculture shows.
Agriculture officials have since Wednesday identified 20 new cases in the state across Doña Ana, Grant, Luna, Otero, Hidalgo and Catron counties, bringing the state’s total to 30 cases since June. A case in Catron County, found in a cow Saturday, marks the first in that county.
In response to the growing number of cases, the New Mexico Department of Agriculture has expanded the state’s “infested zone” — which extends at least 12.4 miles around each of the infested animals’ locations — to regional model, largely on county lines. As of Tuesday afternoon, the infested zone included all of Doña Ana, Grant, Luna, Otero and Hidalgo counties, as well as parts of Catron, Sierra, Lincoln and Chaves counties.
Inside the infested zone, animals, including pets, must be inspected and, if necessary, treated before being moved in or out of the area to support surveillance and prevent the pest from spreading. The designation is intended to help animal owners know whether they need additional inspections or other movement requirements to move livestock, horses, pets or other animals.
“As we work to protect animal health and raise awareness of New World screwworm in the state, we are also working to reduce confusion,” New Mexico Agriculture Secretary Jeff Witte said in a statement. “The new regional zone maps should help people determine whether they are in an area where moving their animals will require an inspection.”
Common in the Caribbean and Central America, New World screwworm larvae burrow into the flesh of warm-blooded creatures such as livestock, pets, wildlife and, in rare cases, people, causing painful and putrid wounds. Left untreated, the infestations can kill an animal in seven to 10 days and greatly hinder livestock operations.
The pest, largely eliminated from the U.S. decades ago, returned to the country in June, with a case identified in a Lea County dog the same month. The U.S. Department of Agriculture has since identified 99 animal infestations across New Mexico, Arizona and Texas.
Recent cases in New Mexico have been identified in cattle, horses, dogs and even a domestic cat in Grant County. Agriculture officials on Thursday also found a New World screwworm fly in a fly trap in Doña Ana County, which is included in the state’s official case count.
As cases have increased, livestock officials have encouraged ranchers, pet owners and hunters to be aware of signs of New World screwworm infestations, like wounds that fail to heal, foul smelling discharge and unusual discomfort around an injury.
The New Mexico Department of Health on Oct. 26 sent out an alert to healthcare providers across the state asking them to keep an eye out for human patients with signs of New World screwworm infestations. So far, no domestically acquired human infestations have been identified in the U.S.
“While human cases are rare, it is critical that healthcare providers be vigilant to assure early detection, prompt treatment, and immediate public health reporting,” the alert stated.
Margaret O’Hara reports on issues affecting healthy communities in New Mexico. Her work is funded by a grant from Anchorum Health Foundation. Anchorum will not have any role in editorial decisions. The New Mexican and its Public Service Journalism Fund retain full editorial control. Philanthropically funded stories by The New Mexican are made available to all readers without a paywall.
