"It contaminates raw eggs, poultry, chicken, and ground beef," says Dr. Bill Short, an infectious disease specialist at Jefferson University Hospital.
Dr. Short says the most common type of salmonella bacteria can also be in cheese and some produce.
The Centers for Disease Control and Prevention says it's hit 388 people in 42 states.
Delaware hasn't had any reported cases.
But New Jersey has 13 cases - 7 in South Jersey. There were 4 reported in Atlantic County, 2 in Camden County, and 1 in Gloucester County.
In Pennsylvania, there are 12 cases - 7 in Philadelphia and the surrounding counties. 2 of the cases were in Bucks County, with 1 each in Philadelphia, Delaware, Chester, Montgomery, and Lehigh counties. Just a little bit further away, Lancaster County has 2 cases.
Most people got sick between mid-October and early December. The latest cases in Pennsylvania and New Jersey came in mid-December.
Because of the time lapse, the source of the bacteria may be difficult to find. Many people may have a hard time recalling what food they ate, or where they ate. In addition, products in their kitchens then may not be around anymore.
Dr. Short says there may be many more cases out there going unnoticed. He says it is possible there are several thousand people who might have had this infection.
"Most people who have nausea, diarrhea for a short time, you chalk it up to "something they ate," and never really seek medical attention," he told Action News.
But Dr. Short says salmonella can be big trouble for some, such as infants, the elderly, or anyone with a weakened immune system.
Until the source of this outbreak is known, prevention is best.
Make sure all of your food is well-cooked.
And, Dr. Short says, "First and foremost, proper handwashing, especially in contact with poultry, chicken, ground beef, or raw eggs."
