Federal officials said they turned up a dangerous form of salmonella at a Cargill Inc. turkey plant last year, and then four times this year at stores selling the Cargill turkey, but didn't move for a recall until an outbreak killed one person and sickened 77 others.
Cargill and the U.S. Department of Agriculture announced the recall of ground turkey from the Cargill plant in Springdale, Ark., on Aug. 3. The USDA said the third-largest meat recall in history affected 36 million pounds of ground turkey.
Food-safety specialists said the delay reflected a gap in federal rules that don't treat salmonella as a poisonous contaminant, even if inspectors find antibiotic-resistant forms such as the Heidelberg strain implicated in the latest outbreak.
"We have constraints when it comes to salmonella," said Elisabeth Hagen, the USDA's top food-safety official, in an interview. She said that unlike E. coli, salmonella isn't officially considered a dangerous adulterant in meat unless that meat is directly tied to an illness or death.
A routine USDA inspection last year of the Cargill plant in Arkansas turned up three samples contaminated with salmonella Heidelberg, the agency said. A USDA spokesman said the agency brought the findings "to the attention of the facility."
Meat plants are expected to pass a performance standard that allows up to 49.9 percent of tests to come back positive for salmonella. A Cargill spokesman said the Arkansas plant had passed all USDA performance standards despite what he called "routine" findings of salmonella Heidelberg.
More warning signs emerged in April from tests by the federal government's National Antimicrobial Resistance Monitoring System, which examines meat samples in retail stores. Researchers from Narms found salmonella Heidelberg in a package of ground turkey that came from the Cargill Arkansas plant.
In May, the Centers for Disease Control and Prevention began investigating clusters of salmonella Heidelberg illnesses that had begun in March. Antibiotic-resistant forms of salmonella such as Heidelberg have become a serious health problem because they cannot be treated with some common antibiotics. If untreated, infections can be fatal.