The Centers for Disease Control and Prevention (CDC) said it is investigating five new cases of an E.coli infection linked to Chipotle Mexican Grill Inc.
The outbreak is of a "different, rare DNA fingerprint" of the Shiga toxin E.coli O26, the CDC said on Monday, adding it is unclear whether it is related to the outbreak that started in October.
Of the five cases reported, one each are from Kansas and North Dakota and three from Oklahoma, the CDC said.
The illnesses started between Nov. 18 and Nov. 26 and all five patients reported eating at Chipotle outlets in the week before falling sick, the CDC said.
"We are in the process of implementing reassessed programs including high-resolution testing of ingredients," Chipotle said.
Reports of new illnesses linked to the October outbreak have "slowed substantially", the CDC said.
Chipotle is grappling with a multistate E.coli outbreak that has sickened about 52 people in nine states and battered the burrito chain's sales and stock price.
The agency also said that a new case of E.coli was reported in Pennsylvania, but noted that the person had not eaten at a Chipotle restaurant. (http://1.usa.gov/1XQTh8z)
Chipotle's shares were down 3.2 percent at $523.60 in late afternoon trading.
(Reporting by Yashaswini Swamynathan amd Natalie Grover in Bengaluru; Editing by Sriraj Kalluvila)