After visiting a raw sewage site in her native Lowndes County, Ala., Catherine Flowers, founder and executive director of the Alabama Center for Rural Enterprise, contracts a mysterious rash. Flowers, whose work focuses on poverty and race, wonders if it’s a disease American doctors don’t test for. Soon she — and 34.5 percent of county residents tested — are diagnosed with hookworm, a sewage-harbored disease long thought eradicated in the U.S. Galvanized, Flowers brings the issue to the worldwide stage — affecting change and adding environmentalist to her bona fides.