Jul 17, 2008 (CIDRAP News) – Federal officials today lifted warnings against eating certain tomatoes and said new clues in the ongoing nationwide Salmonella outbreak have led investigators from the Food and Drug Administration (FDA) to explore a Mexican packinghouse that handles jalapeno and Serrano peppers.
David Acheson, MD, associate commissioner for foods at the FDA, said at a media briefing today that the FDA has removed its warning for consumers to avoid red round, Roma, and plum tomatoes from certain growing regions in Mexico and Florida, because farms in those areas are no longer shipping tomatoes. He said the FDA believes that all tomatoes available within the United States now are safe to eat.
Tracing pepper paths
Case-control studies early in the investigation focused on individual sick patients and strongly suggested tomatoes as the culprit, Acheson said. However, he added that recent studies of later-occurring case clusters, which public health officials say are a more powerful epidemiologic tool, point toward jalapeno or Serrano peppers.
"It's highly unlikely that those tomatoes at the onset are on the market," he said. Investigators have not found the unusual Salmonella enterica Saintpaul strain that is responsible for the outbreak on any of the farms or in any tomato samples.
Though since early July the focus of the FDA's trace-back investigation has been hot peppers, Acheson said investigators haven't ruled out the possibility that contaminated tomatoes caused illnesses earlier in the outbreak. He said investigators are still exploring the possibility that the two products shared a common contamination point, such as a farm, irrigation or wash water, packer, or distributor.
Officials have been at the Mexican pepper packer for only 48 hours and have just started their investigation, Acheson said. "That doesn't mean it's the source, but we're looking at all points on the supply chain. We're getting out to all the places at the same time." He said preliminary findings suggest that the packer does not handle tomatoes.
FDA authorities are continuing to trace and sample both imported and domestic jalapeno and Serrano peppers, Acheson said.
CDC says illness rate slowing
Robert Tauxe, MD, MPH, deputy director of the Centers for Disease Control and Prevention's (CDC's) Division of Foodborne, Bacterial and Mycotic Diseases, told reporters that the number of cases in the outbreak has risen to 1,220 in 42 states, the District of Columbia, and Canada. So far, 224 patients have been hospitalized, and the latest illness onset was Jul 4.
Tauxe said the CDC is now receiving about 20 to 30 new case reports each day, a sign that the intensity of the outbreak has decreased. He said the rate seemed to peak toward the end of May and early June when daily case reports averaged 33. Tauxe told reporters that the CDC would soon publish a chart showing case patterns on its Web site.
Despite the slowing of new case reports, he said the outbreak is still ongoing. CDC investigators are conducting detailed, in-person interviews of patients who were recently ill, Tauxe added.
The CDC is continuing its warning that people in high-risk groups that are susceptible to foodborne illnesses, including infants, those with impaired immune systems, and the elderly, should avoid eating raw jalapeno and Serrano peppers or products that contain them.
Outbreak confounds experts
Acheson said he's never seen a produce outbreak go on for so long and have parallel suspects and investigations. "This isn't following a trail. It's going way beyond shelf life," he said.
Michael T. Osterholm, PhD, MPH, an infectious disease expert who has led large outbreak investigations, voiced more frustrations about the outbreak investigation in an interview with CIDRAP News.
"This is the most frustrating outbreak investigation that I have witnessed in my professional career. There will be many lessons learned," said Osterholm, who had earlier criticized the actions of federal officials and raised concerns about the nation's fragmented food safety system. He is director of the University of Minnesota Center for Infectious Disease Research and Policy, publisher of CIDRAP News.
He said a silver lining might be a renewed effort to define what is needed for an efficient, effective system to reduce human foodborne illnesses and for improved outbreak investigations.
Jul 16 CDC update on Salmonella outbreak