ATLANTA – The Centers for Disease Control and the US Department of Agriculture's Food Safety and Inspection Service are tracking a multi-state outbreak of Salmonella Typhimurium infections linked to ground beef sold from Hannaford Supermarkets.

Nineteen people in seven states have been infected with the foodborne pathogen and seven people have been hospitalized, according to CDC. The victims range in age from 1 year to 79 years old. They reside in Hawaii, Kentucky, Massachusetts, Maine, New Hampshire, New York and Vermont. Illnesses began on or after Oct. 8, 2011, however illnesses that occurred after December may be unreported because two to three weeks can elapse between when a person becomes ill and when the illness is reported, CDC said.

The CDC said the strain of Salmonella Typhyimurium is resistant to several commonly prescribed antibiotics, including amoxicillin, ampicillin and streptomycin. Investigators are using DNA "fingerprint" technology to identify cases that may be associated with the outbreak. The State of Maine Health and Environment Testing Laboratory and the New York State Department of Health isolated the outbreak strain from two separate samples of leftover ground beef purchased from Hannaford stores.

Hannaford, which is based in Scarborough, Maine, is cooperating fully with investigators, and initiated a recall of an undetermined amount of fresh ground beef products on Dec. 15, 2011. The various ground beef packages bear sell-by dates of Dec. 17, 2011, or earlier and were sold at Hannaford stores throughout Maine, Massachusetts, New Hampshire, New York and Vermont, according to FSIS.