USDA cut back on listeria testing nationwide, ahead of deadly Boar’s Head outbreak CBS NewsBoar’s Head faces legal scrutiny over deadly deli meat listeria outbreak, USDA says ABC NewsBoar’s Head plants nationwide now part of law enforcement investigation, USDA says CBS NewsMap shows 19 states affected by listeria outbreak tied to Boar’s Head deli meat USA TODAY10th death linked to Boar’s Head; one popular product discontinued forever OregonLive