Chipotle Stock Closes Below 500 for the First Time in 19 Months

A day after more E. coli reports were linked to Chipotle, the company's stock took another big hit on Wall Street. CMG closed Tuesday at 495.62, down 26.09 points and 5 percent from Monday's close.

Piling on the latest E. coli news was prominent J.P. Morgan analyst John Ivankoe, who downgraded his rating of CMG to "neutral" Tuesday morning. Ivankoe previously thought the public health issues wouldn't be a major problem for investors, writes Market Watch, but he's apparently changed his tune.

"This new case was not contemplated in our previous investment thesis," Ivankoe wrote in a note to clients. "At this point, even rational and informed consumers could potentially be given reason to pause when choosing Chipotle over the plethora of fast casual competition in the marketplace."

CMG is down 34 percent since closing at 750.42 on October 13. Chipotle was first connected to an E. coli outbreak in the Pacific Northwest at the end of October, which resulted in 43 locations temporarily shuttering. Earlier this month, it was revealed the outbreak had spread to nine states, and the Centers for Disease Control added three more states to the list on Monday. Chipotle believes the new cases are part of the original outbreak, but the CDC is investigating to determine if these illnesses are part of a new event.

"Since the last update, we also were made aware of a second, more recent outbreak of a different DNA fingerprint of STEC O26," a CDC spokesperson tells Eater. "Because it is not known if these infections are related to the larger, previously reported outbreak of STEC O26 infections, these illnesses are not being included in the case count for that outbreak. This investigation is ongoing. These five illnesses occurred in the second half of November and all five reported eating at Chipotle before their illness began. These illnesses are in a geographically different part of the country than we have seen in the larger, initial outbreak. We don't know if these illnesses are related to the initial outbreak, but we are investigating and using tools like whole genome sequencing to learn more.

"Whole genome sequencing is being used to determine if this strain is genetically related to the STEC O26 causing the larger outbreak. WGS gives a more detailed DNA fingerprint than the traditional method of DNA fingerprinting called pulsed-field gel electrophoresis (PFGE). We won't have results until January as this advance laboratory process typically takes a couple weeks to complete."

Chipotle has announced a number of changes to improve food safety at its restaurants across the country. In addition to E. coli, the company is dealing with the fallout from a recent norovirus outbreak that was linked to an outpost in Boston. Nearly 140 people were sickened, and the first related lawsuit was filed against Chipotle on Thursday.