Salmonella

Multistate Outbreak of Human Salmonella Saintpaul Infections Linked to Raw Alfalfa Sprouts (Final Update)

Posted April 27, 2009

This outbreak appears to be over. However, Salmonella is an important cause of human illness in the United States. More information about Salmonella, and steps people can take to reduce their risk of infection, can be found on the CDC Salmonella Web Page.

Outbreak Highlights

CDC is collaborating with public health officials in many states and the FDA to investigate a multistate outbreak of human infections due to Salmonella serotype Saintpaul linked to eating raw alfalfa sprouts.
FDA and CDC recommend that consumers not eat raw alfalfa sprouts, including sprout blends containing alfalfa sprouts, until further notice because the product has been linked to Salmonella serotype Saintpaul contamination. Other types of sprouts have not been implicated.

CDC is collaborating with public health officials in many states and the United States Food and Drug Administration (FDA) to investigate a multistate outbreak of human infections due to Salmonella serotype Saintpaul.

Since mid-March, 35 persons infected with the outbreak strain of Salmonella Saintpaul have been reported from 7 states. The number of ill persons identified in each state is as follows: Michigan (17), Minnesota (4), Ohio (3), Pennsylvania (6), South Dakota (2), Utah (1), and West Virginia (2). Cases are still being reported, and possible cases are in various stages of laboratory testing, so illnesses may be reported from other states. No deaths have been reported

Outbreak Investigation

State and local authorities, CDC, and FDA have linked this outbreak to eating alfalfa sprouts. Most of those who became ill reported eating raw alfalfa sprouts. Some reported eating sprouts at restaurants; others purchased sprouts at the retail level.

The initial investigation has traced the contaminated raw alfalfa sprouts to multiple sprout growers in multiple states. This suggests a problem with the seeds used, as well as the possible failure of the sprout growers involved to appropriately and consistently follow the FDA Sprout Guidance issued in 1999. The guidance recommends an effective seed disinfection treatment immediately before the start of sprouting (such as treating seeds in a 20,000 parts per million calcium hypochlorite solution with agitation for 15 minutes) and regularly testing the water used for every batch of sprouts for Salmonella and E coli O157:H7.

This outbreak appears to be an extension of an earlier outbreak in 2009. In February and March, an outbreak of Salmonella Saintpaul infections occurred in Nebraska, South Dakota, Iowa, Kansas, and Minnesota. This outbreak was linked to raw alfalfa sprouts produced at a single facility, and the outbreak strain was indistinguishable from that of the more recently reported cases. CDC is also currently working with public health officials in several states and FDA to investigate an outbreak of Listeria monocytogenes infections linked with eating alfalfa sprouts.

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Clinical Features of Salmonella Infection

Most persons infected with Salmonella develop diarrhea, fever, and abdominal cramps 12–72 hours after infection. Infection is usually diagnosed by culture of a stool sample. The illness usually lasts 4 to 7 days. Although most people recover without treatment, severe infections may occur. Infants, elderly persons, and those with impaired immune systems are more likely than others to develop severe illness. When severe infection occurs, Salmonella may spread from the intestines to the bloodstream and then to other body sites and can cause death unless the person is treated promptly with antibiotics.

More general information about Salmonella can be found here under Salmonella FAQs.

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Advice for consumers

Do not eat raw alfalfa sprouts, including sprout blends containing alfalfa sprouts, until further notice. This warning is only for alfalfa sprouts, not other types of sprouts .
Persons who think they may have become ill from eating raw alfalfa sprouts are advised to consult their health care providers.

REMINDER for high risk populations: CDC and FDA recommend at all times that persons at high risk for complications from Salmonella infection, such as the elderly, young children, and those with compromised immune systems, not eat raw sprouts. For such persons who continue to eat sprouts, FDA recommends cooking them (U.S. Food and Drug Administration, 2002 consumer advisory)