Contamination of seeds for alfalfa sprouts linked to salmonella

Apr 26 2009

The U.S. Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) have recommended 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 at this time.
  
The investigation indicates that the problem may be linked to contamination of seeds for alfalfa sprouts. Because suspect lots of seeds may be sold around the country and may account for a large proportion of the alfalfa seeds currently being used by sprout growers, and cases of illness are spread across multiple states, FDA and CDC are issuing this general advisory.

FDA will work with the alfalfa sprout industry to help identify which seeds and alfalfa sprouts are not connected with this contamination, so that this advisory can be changed as quickly as possible.

CDC, FDA and six State and local authorities have associated this outbreak with eating raw alfalfa sprouts. Michigan, Minnesota, Pennsylvania, South Dakota, Utah, and West Virginia have reported 31 cases of illness with the outbreak strain of Salmonella Saintpaul to CDC. Most of those who became ill reported eating raw alfalfa sprouts.  Some reported eating raw sprouts at restaurants; others reported purchasing the raw sprouts at the retail level.

The illnesses began in mid-March. Cases are still being reported, and possible cases are in various stages of laboratory testing, so illnesses may appear in other states. No deaths have been reported. The number of infected people may be higher than currently reported because some illnesses have not yet been confirmed with laboratory testing.

The CDC and FDA recommend at all times that persons at high risk for complications, such as the elderly, young children, and those with compromised immune systems, not eat raw sprouts because of the risk of contamination with Salmonella or other bacteria.  Salmonella is an organism that can cause serious and sometimes fatal infections in young children, frail or elderly people, and others with weakened immune systems. Healthy individuals infected with Salmonella often experience fever, diarrhea (which may be bloody), nausea, vomiting and abdominal pain. In rare circumstances, infection with Salmonella can result in the organism getting into the bloodstream and producing more severe illnesses, such as meningitis and bone infections.

Initial investigation results trace the contaminated raw alfalfa sprouts to multiple sprout growers in multiple states. This suggests a potential 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 http://www.cfsan.fda.gov/~dms/sprougd1.html. The guidance recommends an effective seed disinfection treatment immediately before the start of sprouting (such as treating seed in 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 contamination.

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, and the outbreak strain was indistinguishable from that of these recently reported cases.  A separate outbreak of Listeria monocytogenes infections was also linked to sprouts in 2009. In the 1990s, a number of outbreaks related to sprouts led FDA to issue its guidance. Experience over the past decade has shown that the likelihood of Salmonella in sprouts can be minimized when recommendations from FDA's Sprout Guidance are followed.

Preventive controls are very important in the growing of alfalfa sprouts. FDA reminds sprout growers to be vigilant in their food safety practices and strongly encourages sprout growers to follow the Agency's Sprout Guidance. Additionally, the United Fresh Produce Association has advised all of its members to follow FDA's guidance on sprouts. FDA appreciates that the produce industry has reinforced this message and reminds retailers that it is prudent to sell sprouts from growers who follow FDA's recommendations.