Officials announced yesterday that an iceberg lettuce which comes from California is to blame for the E. coli outbreak that had sickened more than 36 people from Michigan. Jennifer Holton, a spokeswoman for the Michigan Department of Agriculture, said that "illness dates, ship dates and delivery dates narrow the origin to California."

Ken August, a spokesman with the California agency, also stated that the Food and Drug Administration together with the California Department of Public Health are investigating this case with the help of the state of Michigan. The source of the outbreak hasn’t been determined yet for certain, but it’s believed to be the iceberg lettuce from California.

Escherichia coli, known as E. Coli, is a bacterium usually found in the lower intestine of warm-blood animals. Most of E. Coli strains don’t cause any damage to the intestine, but the ones such as O157:H7, can produce serious food poisoning in humans.

The Michigan Department of Community Health announced that the infected lettuce might have been industrially packed and marketed to different institutions and restaurants. Even if the lettuce is the common product in all the sickened persons, the agencies haven’t got to check all the lettuce. Still, all tests for the lettuce have come back negative.

People started to get sick in September. Victims from Michigan State University, the University of Michigan and Lenawee County Jail started to fall ill since August. Detroit distributor Aunt Mid's Produce Co. was asked to stop the lettuce distribution as some of the vegetable marketed by it sickened some of the people.