US federal health experts at the Center for Disease Control and Prevention warned last week that young children, the elderly and consumers with weak immune systems should avoid eating raw sprouts.

The warning came after the completion of an investigation into an outbreak of a rare form of salmonella across California, Colorado, Arizona and New Mexico last year, which was found to be due to consumption of raw alfalfa sprouts from a single producer.

Protein-rich sprouts can also harbour potentially fatal infections, such as salmonella, because they are grown in moist humid conditions that are the perfect breeding ground for germs.

Dr Mark Beatty of the CDC’s National Center for Infectious Diseases, told Reuters that consumers are often under the “misconception” that sprouts are a health food. “The immuno-compromised people could develop shock and die from the infection,” he said.