20 Jul Starr County Screwworm

Over the weekend, the Rio Grande Valley reported its first case of New World screwworm. On Sunday officials from Starr County confirmed the reported case occurred in a western part of the county and that they are working closely with the Texas Animal Health Commission (TAHC) and other relevant parties to ensure we can contain the spread.

If you are wondering what even is this New World screwworm, don’t worry I got you.

The New World screwworm is a parasitic fly that, unlike ordinary blowflies or houseflies, which feed only on dead tissue, likes to lay its eggs in the open wounds or body openings of living, warm-blooded animals. When these eggs hatch, the larvae use sharp, hook-like mouthparts to burrow deep into healthy living flesh (literally screwing into tissue).

Left untreated, the feeding larvae destroy healthy tissue, cause severe secondary bacterial infections, and can kill an animal within a week to ten days.

We actually eradicated the screwworm in the 1960s using a massive scientific effort called the”Sterile Insect Technique” (releasing millions of sterile male flies to collapse the wild population). And for decades, the US-Mexico border acted as a biological barrier, but the parasite has been steadily migrating north through Central America and Mexico, leading to a recent rise of cases in the United States.

Given the quick damage it can do to livestock, uncontained screwworm outbreaks can cause millions of dollars in damages to ranchers and cattlemen that make a living trading livestock. Given the dependence of Starr County on agriculture and particularly cattle (70% of farmland in Starr County is dedicated to grazing), we can see why this is a pressing issue for us.

But don’t fret, it seems like this outbreak seems very localized which will make it easier for officials to isolate. The U.S. has a good track record of dealing with screwworm outbreaks pretty effectively.