Chipotle Mexican Grill closed all its restaurants in Seattle and Portland due to an outbreak of E. coli bacteria.

The Huffington Post reported that 43 Chipotle restaurants in the Pacific Northwest region have temporarily been closed due to the E. coli scare.

Reuters reported that Chipotle said in a statement that Seattle and Portland health department officials notified the company about 20 cases of E. coli being investigated. Some of the people ate at six of the Chipotle restaurants in these areas. The company immediately closed all of its restaurants as precautionary measure. The company, however, reported that the majority of the stores in those areas had reported no problems in line with the bacteria.

This is the third time that Chipotle restaurants had food contamination outbreak since August. Some of the food contamination that has plagued the business are salmonella and norovirus.

Meanwhile, according to CNN, seven patients from Washington and one from Oregon were hospitalized. Fortunately, no one died from the outbreak yet. The source of the contamination has not yet been determined. However, the 19 cases in Washington and the three cases in Oregon were linked to Chipotle restaurants in the area.

Restaurant consulting firm, Technomic, executive vice president Bob Goldin said, "Short term they (Chipotle) will take a hit but it will blow over quickly. They have a lot of customer goodwill."

The Mexican-themed restaurant opened in 1993 with just one location. Now, it has grown with up to 1,700 chains. It has a reputation of serving healthy and high-quality fresh ingredients. Its menus include burritos, tacos, and salads.

Serving fresh and unprocessed food is becoming a fast growing trend among restaurants. However, experts say this could lead to higher risk of food borne illnesses. Cooking food is important because it kills pathogens.

The Oregon Health Authority said there are still more cases expected to be reported since some who have been infected by the bacteria may not have sought out medical care yet.