Sprouts have long been considered a health food. But all is not well in the world of sprouts. Since 1995, the Centers for Disease Control and Prevention have investigated 15 outbreaks of Salmonella species and two outbreaks of E. coli 0157:H7 infections in the United States associated with raw sprouts. Sprout-associated outbreaks also have been reported in several other countries, including the United Kingdom, Sweden, Finland, Japan, Denmark and Canada. For example, radish sprouts were associated in 1996 with the largest recorded outbreak of E. coli O157:H7 infection, in which 6,000 cases and 17 deaths occurred.
In a case-controlled study reported last fall in the Annals of Internal Medicine, raw sprouts were associated with more than half of the multi-county outbreaks in California from 1996 through 1998. In the report, which investigated six sprout-associated outbreaks (five from Salmonella and one from E. coli O157:H7), they confirmed infections in 600 people (two of whom died) and estimated that approximately 22,800 people suffered gastrointestinal illness or urinary tract infections as a result of sprout consumption.
Since 1999, the sprout industry has initiated several measures to literally clean up their sprouting operations. Despite this, a recent report on an outbreak of Salmonella Kottbus indicates that raw sprouts continue to be a safety concern. This outbreak, which occurred last spring in four states including Colorado, involved alfalfa sprouts produced at a single facility that affected 32 patients. Two of the people affected were immune-compromised and one was a young child. In each case, people perceived raw sprouts as a "healthy" food item.
Sprouts may be contaminated during seed production, germination, sprout processing or consumer handling and preparation. On the farm, sprout seeds may become contaminated through the use of untreated agricultural water, improperly composted manure such as fertilizer, excretion from domestic or wild animals, runoff from domesticated animal production facilities or improperly cleaned harvesting or processing machines. The association of specific seed lots with illness suggests that seeds are the likely source of many sprout-related outbreaks. Conditions favorable for seed sprouting also are ideal for increasing pathogenic bacterial counts on seeds by as much as 10,000 percent.
Public education efforts about the risks of eating uncooked sprouts need to be continued, particularly among vulnerable populations including the elderly, pregnant women, young children and immune-compromised people. The CDC and FDA recommend that people at high risk for systemic infections not eat raw sprouts. They further recommend that raw sprouts not be served in facilities that serve populations at high risk for food-borne illness, including child care centers, preschools, kindergartens, assisted living facilities, nursing homes, long-term care facilities and hospitals.
For healthy consumers who want to continue to enjoy raw sprouts, the following tips can help minimize the risk of foodborne illness.
- Look for the ISGA-certified grower’s seal. This seal certifies that the grower follows the sprout sanitization and growing recommendations of the International Sprout Growers Association.
- Pay attention to the sell-by date printed on the package.
- Check to see if the roots are clean. The stems should appear white or cream in color.
- Give sprouts the sniff test. Fresh sprouts have a clean, fresh aroma.
- Keep sprouts refrigerated and use within a few days.
- Finally, rinse sprouts thoroughly with clean water before serving.