TRENTON — The state Department of Health is investigating six  E. coli cases in at four counties that may be connected to the same restaurant chain.

The cases were reported in Hunterdon, Middlesex, Somerset and Warren counties with the first being reported by a hospital on March 28, State Epidemiologist Dr. Tina Tan told New Jersey 101.5. Tan said the state is working with both the FDA and CDC in their investigation,

The cases may be connected to different locations of a restaurant chain, according to Tank  She would not name the chain until an investigation could make a stronger connection. Tan said The department is in the process of gathering food history data because it can be very difficult to determine where someone got sick.

"Individuals could have eaten a number of meals in a number of places before getting sick. They could have eaten at several restaurants, at home or eaten food purchased at a supermarket. Sometimes the source of the food that made people sick is never determined. That’s why we conduct many interviews with sick individuals to get food history data," Tan said.

She said the state lab will determine if the strains of E. Coli match and the CDC will do another test to confirm.

E. coli, or Escherichia coli, is a bacteria that normally lives harmlessly in the intestines of people and animals, according to the CDC. Some types are pathogenic and can cause illness through exposure to contaminated food or water or contact with animals or other people.

Symptoms include severe stomach cramps, diarrhea (often bloody), and vomiting.

Someone who is exposed may have symptoms within three or four days but there are cases where it starts within a day.

Some infections with recovery within five to seven days. Other cases can be severe and even life threatening.

The CDC recommends that you consult a doctor if you have diarrhea that lasts for more than three days or is accompanied by high fever, blood, or so much vomiting that you cannot keep liquids down and you pass very little urine.

E.mcoli is prevented by thorough hand washing after using the bathroom or changing a diaper before and after food preparation and contact with animals.

Contact reporter Dan Alexander at Dan.Alexander@townsquaremedia.com or via Twitter @DanAlexanderNJ