The E. coli outbreak at Taco Bell restaurants in the United States appears to have passed, a health official said Tuesday as restaurants prepared to reopen.

At least 36 people were affected in New Jersey and New York, and apparently all the victims had eaten at Taco Bell restaurants.

Taco Bell closed one New Jersey restaurant in South Plainfield and four in New York's Suffolk County to sanitize them and replace food ingredients.

"We expect all Taco Bell restaurants to be back in operation today," said Tim Jerzyk, a vice-president of Yum Brands Inc., the parent company of Taco Bell.

New Jersey's top health official described the spate of E. coli sickness as a serious outbreak but said the threat is now over.

"There has not been an outbreak since Nov. 29, so I think that whatever happened went through already," Fred M. Jacobs, health and senior services commissioner, said Monday.

E. coli, or Escherichia coli, is a common and ordinarily harmless bacterium, but certain strains can cause abdominal cramps, fever, bloody diarrhea, kidney failure, blindness, paralysis, even death.

It is most often spread through contaminated food.

Still searching for the source

Medical officials in New Jersey and New York were working with the U.S. Centers for Disease Control and Prevention to try to locate the source of the outbreak that sickened at least 22 people in New Jersey— two of them seriously — and more than a dozen on New York's Long Island.

"We have to find the food they all had in common," said David Papi, director of health for Middlesex County, N.J.

There are 204 Taco Bell restaurants in New York state, and 86 in New Jersey.

All of those who fell ill in New Jersey had eaten at Taco Bells between Nov. 17 and Nov. 28.

The bacteria is often associated with uncooked meat, but can also be found on sprouts or leafy vegetables such as spinach. E. coli can be passed from person to person if they do not thoroughly wash their hands after going to the bathroom.

Earlier this year, three people died and more than 200 fell ill from an outbreak that was traced to packaged spinach grown in California.