89 fall ill in US salmonella outbreak

No deaths have been reported, but around 23 percent of the sick people have been hospitalised, CNN reported.

Health officials said the first cases were identified Nov 1, and preliminary investigation shows a possible link to alfalfa sprouts.

"Preliminary results of this investigation indicate a link to eating alfalfa sprouts at a national sandwich chain," the centre said.

The department of public health said many of the sick people reported eating at locations of Jimmy John's sandwich restaurants.

However, the founder of Jimmy John's said test results of sprouts from its main supplier have tested negative.

Jimmy John Liautaud said all store locations have all come up negative for the bacteria.

According to the centre, Illinois has 50 cases, Missouri 14, Indiana nine, Wisconsin three and Pennsylvania has two cases.

The strain has been identified as Salmonella serotype I-4.

Salmonella is a bacterial infection that usually lasts four to seven days. The infected person develops fever, abdominal cramps and diarrhoea between 12 and 72 hours after becoming infected. Most people recover without treatment.