On March 26, 2009 the US Food and Drug Administration (FDA) informed CDC that multiple samples of pistachio nuts and pistachio-containing products collected over several months from a single company were contaminated with several serotypes of Salmonella, including Montevideo, Newport, and Senftenberg.  Since that time, CDC has been actively investigating whether this contamination is linked to human illness.

FDA has provided PulseNet, the CDC database of bacterial DNA fingerprints, with the DNA fingerprints of the Salmonella strains found in association with the company’s products.  Some of the DNA fingerprints of the Salmonella strains from the pistachio products match the DNA fingerprints of Salmonella strains from recently ill persons already in the PulseNet database.  The number of recent human infections with these strains is not currently above the expected baseline in the United States.  In addition to the pistachios, some of these DNA fingerprints have been associated with other foods, and a fingerprint match does not mean that the illnesses are necessarily linked to pistachios.  CDC is collaborating with state and local public health agencies to interview persons with Salmonella strains having DNA fingerprints that match those from the pistachio products to determine whether they had eaten pistachio nuts or pistachio-containing products before their illnesses.  To date, one patient in Connecticut infected with a Salmonellastrain with a matching DNA fingerprint has reported consuming a pistachio-containing product.

Salmonella that contaminates food, including nuts, can cause human illness and is a public health concern.  CDC estimates that the Salmonella illnesses reported to the public health system represent approximately 3% of the illnesses that actually occur, because many ill persons do not seek medical care or have a specimen cultured.  Even if no reported illnesses are related to a contaminated product, it is possible that some illnesses occurred.

All of the contaminated pistachios came from a single company, Setton Pistachio of Terra Bella Inc, California.  Setton Pistachio has stopped distribution of roasted shelled, roasted in-shell, and raw shelled pistachios from their 2008 crop and has issued a voluntary recall of those products. Companies that receive pistachios from Setton Pistachio continue to recall their products.  The contaminated pistachios may have been used in a wide range of foods, including cakes, cookies, puddings, trail mix, snack bars, and ice cream.