(July 9 -- UPDATED July 10, 4:12 p.m.) With the number of reported illnesses climbing past 1,000 in an outbreak of Salmonella Saintpaul, the Food and Drug Administration expanded its consumer advisory to include fresh jalapeno peppers and serrano peppers — but tomatoes continue to remain on the suspect list.

The outbreak initially was linked to certain types of tomatoes May 31.

“We’re quite certain that neither tomatoes nor jalapenos explain the entire outbreak,” Robert Tauxe, deputy director of the Centers for Disease Control and Prevention’s Division of Foodborne, Bacterial and Mycotic Diseases, said July 9. “We’re presuming that both of them have caused illnesses.”

Steve Sundlof, director of the FDA’s Center for Food Safety and Applied Nutrition, said all samples of tomatoes and peppers taken by the agency have tested negative for Salmonella Saintpaul.

However, epidemiology indicates, in one cluster of illnesses, victims ate food including fresh tomatoes and jalapenos. Meanwhile, ill people in another cluster ate jalapenos but not other implicated foods, Tauxe said. Evidence gathered earlier in the outbreak pointed to tomatoes, he said.

Investigators also are scrutinizing cilantro, but no consumer advisory has been issued for that commodity.

David Acheson, FDA’s associate commissioner for foods, said there is no indication of whether the suspect peppers were imported or domestic.

Acheson said investigators are looking into whether contaminated peppers and tomatoes could have come from a single grower or from a common distribution center.

Through July 9, the outbreak had caused 1,065 illnesses in 42 states, Washington, D.C., and Canada, Tauxe said. Onset of illness dates range from April 10 to June 26, and 315 people had become ill since June 1. More than 200 people had been hospitalized (number of illnesses, states updated July 10).

“This ongoing outbreak is now the largest salmonellosis outbreak ever in the U.S.,” Tauxe said, “and the largest foodborne outbreak of any kind, based on the number of culture-confirmed cases, in the last 10 years.”

Tauxe said people with increased risk of infection — including infants, the elderly and people with impaired immune systems — should not eat jalapenos or serrano peppers.

The FDA and CDC have been criticized by the industry and the media for their inability to pinpoint the cause or the source of the outbreak. Acheson said this is the most complex investigation he has been involved with.

“It’s been a spectacularly complicated and prolonged outbreak,” he said. “I don’t have an explanation for it.”