Chipotle shares have slumped more than 12% on November 20 after the Center for Disease and Control (CDC) reported more cases of E. coli linked to the Mexican restaurant chain.

According to the CDC, 45 people had been infected with a strain of E. coli, 43 of whom reported eating at a Chipotle restaurant.

The cases were in California, Minnesota, New York and Ohio.

Earlier this month, Chipotle temporarily closed 43 outlets in and around Washington and Oregon states.

This was after health officials investigated an E. coli outbreak that made at least 22 people ill.

Photo The Columbian

“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,” the CDC said.

“The investigation is still ongoing to determine what specific food is linked to illness.”

Chipotle shares are now down by almost 19% this year, valuing the company at $17.3 billion.

1. coli, short for Escherichia coli, is a type of bacterium present in the gut of humans and other animals.

Most strains are harmless but some can produce toxins that cause sickness in humans.

According to Mayo Clinic, E. coli infection typically begins three or four days after exposure to the bacteria, though you may become ill as soon as one day after to more than a week later. Signs and symptoms include:

• Diarrhea, which may range from mild and watery to severe and bloody
• Abdominal cramping, pain or tenderness
• Nausea and vomiting, in some people

Contact your doctor if your diarrhea is persistent, severe or bloody.