WASHINGTON -- The government is scrambling to find the source of a salmonella outbreak likely linked to ground turkey that has killed one and sickened dozens more.

Finding the source of an outbreak hasn't been easy; the government has been chasing the illnesses for months. The Agriculture Department, which oversees meat safety, said it is still investigating who produced the meat, and the department hasn't initiated a recall.

California state health officials said Tuesday that the one death was in Sacramento County. Seventy-six people in 26 states have been made sick from the same strain of the disease.

The illnesses date back to March, and the federal Centers for Disease Control and Prevention said Monday that cultures of ground turkey from four retail locations between March 7 and June 27 showed contamination with the same strain of salmonella, though those samples were not specifically linked to the illnesses. The agency said preliminary information showed that three of those samples have been linked to the same production establishment but it did not name the retailers or the manufacturers.

Though the government would not comment, a spokesman for the Minnesota-based meat company Cargill said Tuesday that it had been contacted by the Agriculture Department as part of the investigation.

"We have been contacted by FSIS for information about ground turkey processing, which we have provided for their ongoing investigation into salmonella illnesses," said Michael Martin, referring to the department's Food Safety and Inspection Service.

A spokesman for another large, Minnesota-based producer of ground turkey, Hormel, said Tuesday that the company had not been contacted by USDA about the current investigation

New rules not helping

The silence so far from government officials may be attributed to USDA rules that make it harder to investigate and recall salmonella-tainted poultry. Because salmonella is common in poultry, it is not illegal for meat to be tainted with the pathogen.

Officials must directly link the salmonella illnesses with a certain producer or establishment, which is difficult to do because people don't always remember what they ate or where they bought it.

In this case, it appears that officials haven't been able to prove the link between the samples of salmonella they found -- even though they are the same strain -- and the 77 people who were sickened. The Food Safety and Inspection Service sent out an alert about the illnesses late last week telling consumers to properly cook their turkey, which can decrease the chances of salmonella poisoning.

But the department has not given consumers any further warnings about the source of the tainted meat.

"Despite an extensive investigation by FSIS and CDC to date, there is little epidemiological information available at this time that conclusively links these illnesses to any specific product or establishment," FSIS spokesman Neil Gaffney said Tuesday. "Without specific enough data, it would not be appropriate to issue a recall notice." Gaffney said the agency was committed to finding the source of the outbreak and then take action to protect public health.