When officials at the Food and Drug Administration announced they had found salmonella on a Mexican-grown jalapeno pepper, it meant investigators finally had a solid lead on a trail that seemed to have grown cold.
State health officials in New Mexico first picked up on multiple people getting sick from the same subtype of salmonella — called salmonella Saintpaul — back in April. They reported the cases to the Centers for Disease Control and Prevention in Atlanta.
There, officials analyzing information coming in through an electronic surveillance system began to see that, in pockets around the country, many more states were seeing an unusual increase in cases of salmonella Saintpaul.
As soon as they knew they had an outbreak on their hands, investigators began interviewing sick people, asking them in detail what they had eaten before getting sick. In many cases, people reported eating tomatoes — and the sick people were eating them at much higher rates than their healthy neighbors, who officials also interviewed.
Now, three months later, with the first conclusive match of salmonella Saintpaul coming from a jalapeno pepper, not a tomato, the FDA's lead point person on the investigation, Dr. David Acheson, says it doesn't mean his agency got it wrong.
"The original part of the outbreak, the first scientific indications, showed a very clear association with tomatoes — and there is nothing to indicate that that association was incorrect or inappropriate," Acheson says.
Last week, when the FDA lifted its consumer warnings on eating tomatoes, Acheson explained that none of the farms harvesting tomatoes during the early part of the outbreak were still shipping their product and that all of the tomatoes in markets now had come from areas that were not implicated.
At this point in the investigation, Acheson explained that officials had learned more from a few clusters of people who had been exposed to salmonella at the same time and same place, presumably at a restaurant. They found that these people reported eating fresh jalapeno peppers.
When the FDA dispatched its team of investigators to various points along the distribution chain where the fresh peppers had passed, they knew they needed a direct match.
To make that definitive link, they had to find salmonella Saintpaul on a pepper, which is what happened Monday. Now that consumers have been warned to avoid eating fresh jalapenos, the job of the investigators continues.
One contaminated pepper doesn't solve the whole case. The goal is to continue following the production chain from the distribution center in Texas where the pepper was tested back to the farm in Mexico where it was grown.
"Because it enables us to ultimately, hopefully, pinpoint the source of the contamination which has caused the outbreak," Acheson says.
Since the outbreak began, a total of 1,251 people have gotten sick, and officials at the CDC say they do not believe the outbreak has ended.