Authorities were still trying to determine how and where the victims became infected over the past two weeks. At least 11 of them ate at a Taco Bell restaurant in South Plainfield, and authorities were expected to finish tests on restaurant workers Monday.
Five of the 19 patients were still being treated in hospitals Monday, said Stephanie Brown, an epidemiologist for Middlesex County. Two of them had developed a condition called hemolytic uremic syndrome that can permanently damage the kidneys.
"It's a significant outbreak and it's a serious disease," Middlesex County Director of Health David Papi said Sunday.
At least two of the victims were adults, while most others ranged in age from 7 to 14, Papi said.
Papi said an inspection of the restaurant, which was closed voluntarily, did not detect any significant health code violations. Tests were being performed on 21 restaurant employees and officials were still looking for a few other workers.
The restaurant chain's employees are required to adhere to strict food-handling rules, said Rob Poetsch, a spokesman for Taco Bell Corp., based in Irvine, Calif.
"We have taken every precaution, including temporarily closing the restaurant until the investigation is completed, as nothing is more important to us than the health and safety of our customers and employees," Poetsch said in a statement.
E. coli, short for Escherichia coli, is a common and ordinarily harmless intestinal bacteria.
According to the Centers for Disease Control and Prevention, the strain of E. coli that caused the New Jersey infections is often found in the intestines of healthy goats, sheep and cattle.
Most E. coli infections are associated with undercooked meat. However, the bacteria also can be found on sprouts or green leafy vegetables such as spinach, the CDC said. Earlier this year, three people died and more than 200 fell ill from an E. coli outbreak that was traced to packaged spinach grown in California.
The bacteria also can be passed from person to person if they don't take steps such as thoroughly washing their hands.