ATLANTA — Shoppers are leaving jarred peanut butter off their grocery lists, according to sales figures, even though familiar brands have not been affected by the salmonella outbreak that has sickened hundreds and led to one of the largest product recalls in U.S. history.

To fight the sales slump, the makers of Jif and Peter Pan have countered with a costly advertising campaign aimed at reassuring nervous eaters.

Jarred peanut butter sales during the four weeks ending Jan. 24 dropped 22 percent from the same period the previous year, according to figures compiled by The Nielsen Company, which tracks consumer purchasing decisions. The 33.8 million pounds of peanut butter includes jars sold at food, drug and mass merchandisers, but not Wal-Mart stores.

Although more recent data weren't available Monday, hundreds more products have been recalled since the period measured by Nielsen, making the peanut industry's woes even more visible to consumers. As a result, some consumers say they're avoiding peanut butter entirely.

"I just stopped because I didn't want to risk anything happening," said Kate Labrecque, 24, as she ate lunch in a downtown Atlanta park. She said she's waiting until "they put something out that says it's safe to eat stuff with peanuts."

Federal investigators have linked peanut products made at Peanut Corp. of America's southwest Georgia peanut processing plant to the salmonella outbreak that has sickened 575 people and might have caused as many as eight deaths.

On Monday, the FBI raided the plant in Blakely, Ga., hauling off boxes and other material. Agents executed search warrants at both the plant and at Peanut Corp.'s headquarters in Lynchburg, Va., according to a senior congressional aide with knowledge of the raids. The official spoke only on condition of anonymity because he was not authorized to speak publicly on the matter.

The Lynchburg, Va.-based company sold its peanut butter to institutional clients, such as nursing homes, and its peanut paste to many other companies that used it as an ingredient in products ranging from cookies and ice cream to energy bars and pet treats. While the company initially said its products weren't sold directly to consumers, it said Sunday that some of its products — including dry and honey-roasted nuts — were also sold directly to consumers at the retailers 99 Cent Stuff, 99 Cents Only Stores, Dollar General, and Dollar Tree Stores.

Leading brands of jarred peanut butter, however, aren't part of the scandal, and their makers have found themselves scrambling to spread that message to shoppers.