Chipotle E. coli outbreak expands: California, New York, Oregon, Washington

In October, the company had forecast sales at established locations would be up in the low- to mid-single digit percentages for 2015.

This is a huge and the very first such decline in the company’s history.

Prior to Friday’s report, the onset of most cases of illness had been in late October. These are Pennsylvania, Ohio, New York, Minnesota, Maryland, Illinois and California.

The company noted in an SEC filing that sales have fluctuated a great deal along with developments in the E. coli outbreak – falling when stores closed, but rebounding when they reopen.

For the past few months, Chipotle has been under the radar, with federal authorities investigating a pathogenic E. coli strain, which has now affected 52 people across nine states, with 47 of these individuals saying they ate at Chipotle right before they fell sick.

The most recent illness started on November 13, it said. It said it will also enhance employee training for food safety and handling.

According to the CDC, most people infected with E. coli develop symptoms three to four days after contact with the germ.

The Mexican food chain said it hired IEH Laboratories in Seattle to help improve its system, and that new procedures will include testing of all produce before it is shipped to restaurants. This program includes the process of testing the quality of food, especially the fresh produce, before sending it to their branches.

Chipotle said Friday it tested ingredients before, but that it is moving to testing smaller batches and a larger number of samples. While that may be good for nutrition, experts say it raises the risk of food-borne illness because cooking kills pathogens.

An estimated 48 million Americans get sick each year from foodborne diseases. Investigators said that the outbreak of the infectious disease could even widen. Of these, 128,000 are hospitalized and 3,000 die, according to the CDC.

The epidemiologic evidence available at this time suggests that a common meal item or ingredient served at Chipotle Mexican Grill restaurants in several states is a likely source of this outbreak.

Earlier Friday, Chipotle had said it was tightening its food standards.