Federal health officials have been investigating an "outbreak of Listeria with unknown source" in 15 states.
The source of the outbreak has not been determined yet. CDC is still concerned about the number of illnesses reported. Listeria is a rare illness, but can cause serious illness or even death," according to a recent report.
Read the Centers for Disease Control and Prevention's (CDC) website.
It is possible that the total number of infections may be higher than currently reported. According to CDC statistics, 18 infections have led to 17 hospitalizations across 15 states. No fatalities have yet been reported.
Michigan and Wisconsin were the only two states that reported two illnesses. Illinois, Arkansas California Colorado Missouri New York North Carolina Pennsylvania South Dakota Washington and Washington each reported one.
The CDC has created an outbreak map.
The CDC stated that "public health officials are interviewing those in this outbreak, to determine what foods they ate prior to getting sick." They added that the infection was "especially dangerous if you're pregnant, 65 years old or older, or if your immune system is weakened."