An E. coli outbreak in New Jersey has a 100 percent hospitalization rate and is  possibly linked to eating at Panera Bread, based on patient interviews.

Although state health officials did not specifically name Panera Bread in an undated statement posted this weekend, local officials have told media in New Jersey that their investigation includes Panera Bread.

“The department is investigating a possible association with a chain restaurant, but the association may be broader than a single chain restaurant. The department is in the process of gathering food history data from those who became ill,” according to the statement from the New Jersey Department of Health.

All eight people confirmed with E. coli infections had symptoms so severe that they required hospitalization. Three of them were still in the hospital as of this weekend. The sick people are spread across four counties, Somerset, Hunterdon, Middlesex and Warren.

State and local health officials are working with the U.S. Food and Drug Administration and the Centers for Disease Control and Prevention on the outbreak investigation. Laboratory test results were not yet available when the state health department posted its outbreak statement. 

If the test results show the victims were infected with the same strain of E. coli it will be strong evidence that there is a common source. The CDC will conduct follow-up tests to confirm the results if the strains match.

“We’re working with the FDA district office in New Jersey and our own investigators to trace back sources of food the individuals may have eaten as well as looking at records such as invoices of vouchers of food deliveries made to any of the restaurants that may be part of the investigation,” according to the New Jersey health department statement.

Most people infected with E. Coli usually get better within about five to seven days, however, some infections can be serious or even life-threatening. Symptoms can include diarrhea that lasts for more than three days or is accompanied by high fever, blood in the stool, or so much vomiting that people cannot keep liquids down and they pass very little urine.

In addition, about 5 percent to 10 percent of people, especially children, who are diagnosed with Shiga toxin-producing E. coli infections develop a potentially life-threatening complication known as hemolytic uremic syndrome (HUS). HUS develops about a week after symptoms first appear, when diarrhea is improving, according to the New Jersey health department.