Food poisoning: Sprouts linked to bouts.

Alfalfa and other sprouts provide a rich source of vitamins, minerals, and even natural cancer-fighting compounds (SN: 9/20/97, p. 183). However, the seeds from which these nutritious shoots are grown may be tainted with germs, a new analysis finds. Indeed, researchers have traced a protracted North American Salmonella enterica outbreak 3 years ago to alfalfa sprouted from seed contaminated with the bacterium.

The investigation was kicked off in the Pacific Northwest by 133 poisonings caused by an unusual type of S. enterica known as Newport. Initial probes showed that many Newport victims in Oregon recalled having eaten sprouts. Chris A. Van Beneden of the Centers for Disease Control and Prevention in Atlanta and his colleagues traced the sprouts to a batch of Dutch seeds. Upon testing, the seeds proved to harbor Newport Salmonella germs. The researchers eventually linked many earlier Newport cases in the central and eastern United States to consumption of sprouted seeds from the same Dutch source.

On the basis of the number of Newport cases in these outbreaks and the fact that only about 5 percent of Salmonella poisonings tend to be reported, "we estimate that more than 20,000 persons contracted Newport infections from eating these contaminated alfalfa sprouts in North America alone," Van Beneden's team concludes in the Jan. 13 Journal of the American Medical Association.

Such outbreaks, the researchers say, "heighten concern about the safety of a familiar food"--especially one that is rarely washed or cooked. Indeed, they argue, sprouts appear to constitute a high salmonella risk because the commercial sprouting process "contains no `kill step' that would eliminate pathogens without compromising a seed's germination."