NEW YORK (TheStreet) -- Chipotle Mexican Grill (CMG - Get Report) stock is plummeting 8.59% to $558.99 on heavy trading volume on Friday afternoon after restaurants in three additional states were linked to an E. coli outbreak.

Cases of E. coli were reported in California, Minnesota and New York by the Centers for Disease Control and Prevention.

The first outbreak in Oregon and Washington was reported earlier this month by the Oregon Health Authority.

A total of 45 cases of E. coli, a bacteria that causes diarrhea, abdominal cramps and, in severe cases, fever and kidney failure, have been reported between October 19 and November 8.

Most of the cases are in Washington and Oregon, with two being reported in each California and Minnesota and one in New York.

The investigation is ongoing, but the CDC has found that 43 of the 45 people ate a Chipotle restaurant, making it the likely source of the outbreak.

The CDC is still searching for a common ingredient consumed by the affected people to find the exact item that caused the outbreak.

Chipotle is cooperating with health officials on the investigation, the CDC noted.

So far today, 2.56 million shares of Chipotle have been traded, compared with its average daily volume of 630,448 shares.

Separately, TheStreet Ratings team rates CHIPOTLE MEXICAN GRILL INC as a Buy with a ratings score of B+. TheStreet Ratings Team has this to say about their recommendation:

We rate CHIPOTLE MEXICAN GRILL INC (CMG) a BUY. This is driven by a few notable strengths, which we believe should have a greater impact than any weaknesses, and should give investors a better performance opportunity than most stocks we cover. The company's strengths can be seen in multiple areas, such as its revenue growth, growth in earnings per share, increase in net income and notable return on equity. We feel its strengths outweigh the fact that the company has had lackluster performance in the stock itself.

Highlights from the analysis by TheStreet Ratings Team goes as follows:

  • The revenue growth came in higher than the industry average of 1.4%. Since the same quarter one year prior, revenues rose by 12.2%. Growth in the company's revenue appears to have helped boost the earnings per share.
  • CHIPOTLE MEXICAN GRILL INC has improved earnings per share by 10.6% in the most recent quarter compared to the same quarter a year ago. The company has demonstrated a pattern of positive earnings per share growth over the past two years. We feel that this trend should continue. During the past fiscal year, CHIPOTLE MEXICAN GRILL INC increased its bottom line by earning $14.13 versus $10.46 in the prior year. This year, the market expects an improvement in earnings ($17.31 versus $14.13).
  • The net income growth from the same quarter one year ago has greatly exceeded that of the S&P 500, but is less than that of the Hotels, Restaurants & Leisure industry average. The net income increased by 10.8% when compared to the same quarter one year prior, going from $130.80 million to $144.88 million.
  • The return on equity has improved slightly when compared to the same quarter one year prior. This can be construed as a modest strength in the organization. Compared to other companies in the Hotels, Restaurants & Leisure industry and the overall market on the basis of return on equity, CHIPOTLE MEXICAN GRILL INC has underperformed in comparison with the industry average, but has exceeded that of the S&P 500.
  • The gross profit margin for CHIPOTLE MEXICAN GRILL INC is currently lower than what is desirable, coming in at 28.31%. It has decreased from the same quarter the previous year. Along with this, the net profit margin of 11.90% trails that of the industry average.
  • You can view the full analysis from the report here: CMG

Any reference to TheStreet Ratings and its underlying recommendation does not reflect the opinion of Jim Cramer, TheStreet or any of its contributors.