New World Screwworm Rapid DNA Field Testing Tool

Early detection and rapid response are critical to controlling the spread of New World Screwworm, a blowfly pest that has re-emerged in the U.S. As the USDA leads the federal response, USGS Ecosystems Mission Area scientists are developing and validating a rapid DNA field test that can be used onsite with basic training and simple materials that easily fit in a small space to support surveillance and response efforts.  

Point-of-Use Tool Development  

USGS scientists are using a DNA test called LAMP (loop-mediated isothermal amplification) that is designed to work fast. LAMP assays quickly identify a target pest’s DNA. They rely on short pieces of engineered DNA that act like ‘search helpers,’ sticking to matching parts of the pest’s genes. Once they attach, an enzyme leads to a rapid creation of new DNA fragments, much like a chain reaction, that happens over just a few minutes. The test only requires a heat block for equipment and is easy to learn, even for people without a science background. 

The results can be visualized using ultraviolet light, a test strip, or a color change reaction. The USGS is also evaluating two test methods that provide an easy visual readout of results: 1) the use of fluorescent dyes with a fluorometer and 2) the use of a lateral flow assay strip.