South Australians are being warned not to eat a range of alfalfa sprout products after the sprouts were linked to 21 confirmed cases of Salmonella.

Several cases of salmonella have been linked to South Australian alfalfa sprout products, prompting state authorities to issue a health warning.

SA Health's chief medical officer Professor Paddy Phillips said there have been 21 recent confirmed cases of salmonella in people who have eaten SA Sprouts alfalfa sprouts.

"We are advising anyone who has purchased the recalled SA Sprouts alfalfa sprouts products to return them to the place of purchase for a refund, or throw them away," Professor Phillips said on Wednesday.

"We also want to alert cafes and restaurants to check their suppliers and not serve any SA Sprouts alfalfa sprout products until further notice."

Professor Phillips said the source of the salmonella was identified through a joint investigation between SA Health, local government and Primary Industries and Regions SA.

"We are working closely with the producer and suppliers while we continue to investigate," Professor Phillips said.

Salmonella symptoms may surface between six and 72 hours after exposure, and can last up to seven days.