Poor sanitation at a Boar’s Head factory here in Virginia contributed to a massive listeria outbreak late last year. A new report from the U.S. Department of Agriculture says inspectors found “meat and fat residue from the previous day’s production on the equipment, including packaging equipment.” The listeria outbreak resulted in the deaths of 10 people and left dozens more in the hospital. At least 19 different states had confirmed cases, the largest outbreak of foodborne illness since 2011.