A spokeswoman from Caldwell Fresh Foods reported on Monday that the alfalfa sprouts sold to more than 400 Wal-Mart stores in 15 states were recalled because of salmonella poisoning.

The raw sprouts were sold to Wal-Marts in Alabama, California, Georgia, Iowa, Illinois, Indiana, Kansas, Kentucky, Louisiana, Missouri, Mississippi, Nebraska, Nevada, Oregon and Wisconsin and they have sickened at least 22 people so far.

Salmonella is an organism that can cause serious and sometimes fatal infections in those with weakened immune systems. It can cause diarrhea, fever and vomiting.

Caldwell Fresh Foods did not give any comment about it and no one answered the phone at the company's headquarters on Monday.

The report about these contaminated sprouts came into light when a 4-month-old baby boy ate alfalfa sprouts mixed with other foods. His sickness made the cause of the outbreak easier to identify because the infant had not yet eaten many foods. He was hospitalised but later recovered.

The sprouts were removed from the produce departments of the affected stores as soon as the retail chain was made aware of the recall.

According to Foodsafety. gov, there have been at least 30 reported outbreaks of foodborne illness associated with different types of raw and lightly cooked sprouts since 1996 and the Government has long recommended that children, the elderly, pregnant women, and people with weakened immune systems should avoid eating raw sprouts of any kind — that includes alfalfa, clover, radish, and mung bean sprouts.