Six deaths have been linked to the outbreak, which has sickened more than 470 people in 43 states, including 13 in Washington state. Three of them live in King County.
The 13, who range in age from under 10 to in their 50s, have all recovered and none had to go to hospitals, said Donn Moyer, spokesman for the Washington state Department of Health.
Most of their cases were reported in November, Moyer said, and the rest in early December.
Moyer encouraged anyone who thinks they might be suffering from salmonella to see a doctor or other health professional.
"That helps us track the disease in a way that helps us prevent more cases," he said.
Most peanut butter sold in jars at supermarkets appears to be safe, said Stephen Sundlof, head of the Food and Drug Administration's food-safety center.
But health officials said consumers who have bought any of the recalled products should throw them away. And consumers should avoid eating any products with peanut butter until more information is available about which brands may be affected.
Officials are focusing on peanut paste and peanut butter produced at a Blakely, Ga., facility owned by Peanut Corp. of America. Its peanut butter is not sold directly to consumers but distributed to institutions and food companies. The peanut paste, made from roasted peanuts, is used as an ingredient in cookies, cakes and other products that people buy in the supermarket.
"This is an excellent illustration of an ingredient-driven outbreak," said Dr. Robert Tauxe, who oversees food-borne-illness investigations for the federal Centers for Disease Control and Prevention (CDC).
Salmonella is a bacteria and the most common source of food poisoning in the United States, causing diarrhea, cramping and fever.
Officials said new illnesses are being reported.
Kellogg Co., which listed Peanut Corp. as one of its suppliers, has recalled 16 products. They include Austin and Keebler branded Peanut Butter Sandwich Crackers, and some snack-size packs of Famous Amos Peanut Butter Cookies and Keebler Soft Batch Homestyle Peanut Butter Cookies.
Health officials said consumers who have bought any of those products should throw them away.
Hy-Vee of West Des Moines, Iowa, a Midwest supermarket chain, has recalled all bakery products made with peanut butter. Perry's Ice Cream, based in Akron, N.Y., said it was recalling select ice-cream products containing peanut butter. Those recalls covered states in the Midwest and the East Coast.
Peanut Corp. has recalled all peanut butter produced at the Georgia plant since Aug. 8 and all peanut paste produced since Sept. 26. The plant passed its last state inspection this summer, but recent tests have found salmonella.
Health officials are focusing on 30 companies out of 85 that received peanut products from the Georgia plant. Sundlof said Peanut Corp. is a relatively small supplier on the national scene.
But Seattle-area lawyer William Marler, who specializes in food-safety cases, said the government shouldn't wait for the results of more tests to request recalls.
"At least 30 companies purchased peanut butter or paste from a facility with a documented link to a nationwide salmonella outbreak," said Marler. "The FDA has the authority actually, the mandate to request recalls if the public health is threatened. Instead, the FDA has asked the companies to test their products and consider voluntary recalls. It is just not enough."
Washington usually has about 800 cases of salmonella each year, Moyer said, but these 13 are the ones that have been tied to the national outbreak.
State and local officials were not able to identify the source of their illnesses when they were sick, Moyer said, but now that the 13 cases have been tied to this outbreak, the people will be re-interviewed.
State and local health officials also have notified physicians to be on the lookout for possible salmonella cases.
The outbreak has triggered a congressional inquiry and renewed calls for an overhaul of food-safety laws. For example, the FDA lacks authority to order a recall, and instead must ask companies to voluntarily withdraw products.
"Given the numerous food-borne-illness outbreaks over the past several years, it is becoming painfully clear that the current regulatory structure is ... ill-equipped to handle these extensive investigations," said U.S. Rep. Rosa DeLauro, D-Conn., who chairs a panel that oversees the FDA budget.
Health officials in Minnesota and Virginia linked two deaths each to the outbreak and Idaho has reported one. Four of those five were elderly, and all had salmonella when they died, although their exact causes of death have not been determined. The CDC said the salmonella may have contributed.
An elderly North Carolina man died in November from the same strain of salmonella that's causing the outbreak, officials in that state said Friday.
The CDC said the bacteria behind the outbreak — typhimurium — is common and not an unusually dangerous strain but that the elderly or those with weakened immune systems are more at risk.