April 27, 2009 -- The FDA and the CDC are advising people not to eat raw alfalfa sprouts after at least 31 people were sickened by Salmonella Saintpaul infection.

Those cases have occurred in six states: Michigan, Minnesota, Pennsylvania, South Dakota, Utah, and West Virginia. Most of the patients reported eating raw alfalfa sprouts. Cases began in March and are still being reported.

According to the FDA, an investigation shows that the problem may be linked to contamination of seeds for alfalfa sprouts.

The FDA and the CDC note that suspect lots of seeds may be sold around the country and may account for a large proportion of the alfalfa seeds being used by sprout growers, and cases of illness are spread across multiple states.

The warning doesn't apply to any other type of sprouts, just raw alfalfa sprouts. But the FDA and the CDC always recommend that people at high risk for complications, such as the elderly, young children, and people with compromised immune systems, not eat raw sprouts because of the risk of contamination with salmonella or other bacteria.

Salmonella can cause fever, diarrhea (which may be bloody), nausea, vomiting, and abdominal pain. Severe cases are more common in the elderly, young children, and people with compromised immune systems.