US Food and Drug Administration (FDA) officials said on Wednesday that a sample of serrano pepper and a sample of irrigation water taken from a farm in Mexico contained Salmonella saintpaul with the same genetic fingerprint as the strain in the outbreak that started over 3 months ago and has sickened more than 1,300 people throughout the United States and parts of Canada.

David Acheson, FDA associate commissioner for food protection, made the announcement at the first of two congressional hearings into what went wrong in the investigation. Officials from the FDA and Centers for Disease Control and Prevention (CDC) were summoned to testify at the hearing.

According to Reuters, FDA spokeswoman Stephanie Kwisnek confirmed that:

“FDA found Salmonella saintpaul in a sample of serrano peppers and a sample of water from a farm in Mexico.”

The Washington Post said US tomato growers and Congress have heavily criticised the CDC’s and the FDA’s handling of the outbreak investigation, which first focused on raw red tomatoes and then expanded to include raw jalapeño and serrano peppers.

The samples were taken from a farm in the northeastern Mexican state of Nuevo Leon which partially borders Texas. The FDA is now advising consumers that jalapeño and serrano peppers grown in the United States are not connected with the current Salmonella saintpaul outbreak, and “consumers may feel free to eat them without concern of contamination”.

As well as raw jalapeño and serrano peppers grown in the US, commercially canned, pickled and cooked jalapeño and serrano peppers from any source are not connected with the current outbreak.

The FDA said the advisory to avoid eating raw jalapeño and raw serrano peppers, and dishes that contain them, applies only to those grown or packed in Mexico.

According to Reuters, the Mexican government has rejected the FDA findings, saying that the sample they tested came from stagnant water in a tank of rainwater that was not used to irrigate peppers.

Enrique Sanchez, the food health director at Mexico’s Ministry of Agriculture told Reuters in Mexico City that:

“What they took was a sample from soil after the harvest. That is not scientifically valid in any part of the world.”

Meanwhile, the Mexican government has suspended food exports from the company the FDA suspects is the cause of the outbreak. A statement issued by the Mexican embassy in Washington said Mexico hopes the two countries can work together to find the source of the outbreak so that “producers not associated with it can be cleared to resume business, in a manner which ensures the health and well-being of consumers,” reported Reuters.

According to the Washington Post, the discovery of the outbreak strain on the Mexican farm does not answer all the questions surrounding this outbreak, but it improves the chances of stopping it and brings officials closer to a fuller explanation of how the country’s most experienced investigators have taken so long to trace the source of the outbreak.

The Post said the discovery has not entirely “let the FDA and the CDC off the hook”, the Congressional hearing asked Acheson to come back with more answers, for instance when did he know from the CDC that they suspected jalapeño peppers were making people ill.

This question is important because it was not until early July that the investigation expanded to include jalapeño and serrano peppers, and until then the whole country was being advised to avoid raw red plum, Roma and vineless red round tomatoes. Tomato growers are very angry because they have incurred more than 100 million dollars in losses, said the Post.

Although they have yet to find a contaminated tomato, FDA and CDC officials maintain that tomatoes could have been contaminated anywhere along the supply chain, for instance by being stored with contaminated peppers. Acheson told the hearing that it was “plausible” that tomatoes were the cause of the illnesses in the early phases of the outbreak.

Most people who become infected with Salmonella get diarrhea, fever, and abdominal cramps about 12 to 72 hours later and the illness lasts for 4 to 7 days. Although most recover without treatment, infections can become severe, and infants, the elderly and people with weakened immune systems are most at risk. When severe infection occurs, Salmonella can get into the bloodstream from the intestines and then to other parts of the body, which can be fatal. Antibiotic treatment may be necessary for the most severe infections.

Click here for the latest CDC update on the outbreak and the investigation.

Click here to see photos of raw jalapeño and serrano peppers (FDA).

Source: FDA, Reuters, Washington Post, CDC.

Written by: Catharine Paddock, PhD