Some 26 states reported the illness between March 1 and August 1, with Michigan, Ohio, Texas, Illinois, California and Pennsylvania reporting the most cases, the Centers for Disease Control and Prevention said.
Public health officials were still looking for the source of the contamination, but preliminary information suggested that a single production facility may be involved.
The U.S. Department of Agriculture's Food Safety and Inspection Service issued a public health alert last week for frozen or fresh ground turkey, advising consumers to cook the meat until it reaches 165 Fahrenheit (74 Celsius) on a food thermometer.
The Salmonella heidelberg strain behind the outbreak is resistant to many commonly prescribed antibiotics. That antibiotic resistance can raise the risk of hospitalization or treatment failure in infected individuals, the CDC said.
Most people infected with Salmonella bacteria develop diarrhea, fever and abdominal cramps 12 to 72 hours after exposure. Illness usually lasts four days to one week and most people recover without treatment.
In some cases, individuals develop severe diarrhea that requires hospitalization. The infection may also spread from the intestines to the bloodstream and on to other parts of the and can cause death without prompt treatment with antibiotics.
Older adults, infants, and those with impaired immune systems are more likely to have a severe illness from Salmonella infection.
The Center for Science in the Public Interest, a consumer group, earlier this year petitioned USDA to declare antibiotic-resistant Salmonella heidelberg and three other strains that have caused outbreaks and recalls as "adulterants."
"That would trigger new testing for those strains and make it less likely that contaminated products reach consumers," CSPI said on Tuesday.
The CDC estimates that one in six people in the United States gets sick from eating contaminated food each year. Foodborne illness is blamed for about 3,000 deaths annually.