July 2026

New World screwworm (NWS), or Cochliomyia hominivorax, has recently been reported in eight counties in Texas. New World screwworm poses a significant risk to wildlife, livestock, companion animals, and public health. This myiasis-causing parasitic fly is native to the Americas and can inflict extensive tissue damage and, depending on the severity and anatomical location of the infestation, may be fatal. Female flies lay their eggs in fresh wounds on living, warm-blooded animals.

Adult New World screwworm fly (*Cochliomyia hominivorax*)

New World screwworm was eradicated in the United States in 1966 through the release of sterile male flies, but cases have now reemerged. On June 3, 2026, the first report of New World screwworm occurred in Zavala County, Texas.

Map of Texas highlighting counties with active and inactive New World screwworm cases. — Texas counties with active and inactive New World screwworm cases

Texas A&M AgriLife Extension has provided valuable resources to help producers, veterinarians, and pet owners understand and respond to this emerging threat. These include a companion animal care fact sheet authored by our own Drs. Guilherme G. Verocai and Rafael Ramos.

Close-up of a New World screwworm larva. — New World screwworm larva

Resources

Texas A&M AgriLife Extension – New World Screwworm Information

https://agrilifeextension.tamu.edu/new-world-screwworm

Companion Animal Care and New World Screwworm Fact Sheet

https://agrilifeextension.tamu.edu/companion-animal-care-nws/

The Verocai Parasitology Lab traveled to Rio Grande, Puerto Rico, for the 71st Annual Meeting of the American Association of Veterinary Parasitologists (AAVP). Our team showcased a diverse collection of presentations highlighting the exciting research underway at Texas A&M. We had a fantastic time learning, sharing ideas, and connecting with colleagues across the parasitology community. Explore the presentations and awards below to see what we’ve been up to.

Presentations:

Anna Schmieding: Assessing prevalence of Angiostrongylus cantonensis in rats from three different regions of Texas (Oral presentation)

Brian Reiber: Understanding canine gastrointestinal parasites co-infections in Chad: Impact on Guinea Worm diagnostic and One Health implications (Oral presentation)

Cassia Matos Ribeiro: Detection ofAngiostrongylus cantonensisin synanthropic rodents and marsupials from Ilhéus, Bahia, Brazil (Poster presentation)

Guilherme G. Verocai: Vector-borne pathogens and molecular detection ofDirofilaria immitisandOnchocerca lupiin dogs from Chad, Sub-Saharan Africa (Oral presentation)

Guilherme G. Verocai: Cytokine profiles of dogs experimentally infected withDracunculus medinensis (Oral presentation)

Guilherme G. Verocai: A One Health evaluation of filarioid nematodes associated with Ixodid ticks collected from domestic dogs in Chad (Oral presentation)

Maureen Kelly: Enhanced molecular diagnosis ofOnchocerca lupiusing droplet digital PCR in clinically suspected companion animals (Oral presentation)

Tiana Sanders: Case series of angiostrongyliasis from a zoological facility in Houston, Texas, USA (Oral presentation)

Tiana Sanders: Surveillance for macrocyclic lactone (ML)-resistant isolates ofDirofilaria immitisfrom shelter dog populations in Texas (Oral presentation)