Screwworm spread tests US readiness after Trump staffing cuts

The U.S. spent decades driving the New World screwworm far into South America. But now the parasite has reemerged, and officials are working to beat it back yet again using many of the same tried-and-true methods as the government did in the 1950s.  Experts have been tracking the path of parasitic fly as it moved steadily northward...