Federal government decided to declare the end of Chipotle outbreak. Centers for Disease Control and Prevention (CDC) has not been able to find source of e.coli that sickened more than 50 customers all across United States.

A terrible food-borne illness have strucked Chipotle last year. The first wave of outbreak started in Minnesota and California, then followed in late October to November in Washington and Oregon. The recent case was in December in Boston, Massachusetts.

The investigation took place to find the source of the outbreak, especially in the Pacific Northwest area since last October. In which more than 50 customers were sickened after dining in at Chipotle Mexican Grill. In total, the e.colu outbreak that hit Chipotle occurred in 11 states.

Reuters reported that according to U.S. Centers for Disease Control and Prevention, people infected with E.coli usually develop its symptoms in three to four days after contact with the bacteria. The infection are spread via oral contach with fecal matter, in some serious case the infection can be a life-threatening one.

On Monday, CDC officially announced to close the investigation on Chipotle outbreak. The agency also declared the outbreaks appear to be over. Chipotle spokesman Chris Arnold told USA Today, "We are pleased that the CDC has concluded its investigation, and we have offered our full cooperation throughout."

"Over the past few months we have taken significant steps to improve the safety of all of the food we serve, and we are confident that the changes we have made mean that every item on our menu is delicious and safe," mr. Arnold added.

The incident has taken a huge blow to Chipotle. Wall Street Journal reported that Chipotle's sales and stock price have been slipping since news of the outbreak began surfacing in the Pacific Northwest in late October. Most of all, it hurt Chipotle reputation.

Different than any other fast-food restaurant, Chipotle is famous for preparing meals by hand, right in front of the customer. That is how Cipotle built its reputation. Relying on fresh ingredients, and very often they are locally sourced.

Following the outbreak, last December in one of the TV talkshow, CEO Steve Ells promised to put more stringent guidelines for food preparation to protect its customers. Chipotle has also launched a series of marketing campaign and targeted promotions this month.

In regard to win customers, NPD Group research firm published one surprising result about Chipotle customers. Younger Chipotle customers, teen and young adults ages 13-24 never seem to leave Chipotle. In fact, from October through December which the outbreak was on the rise, visits from customers on the age group increased by more than 10%. Still, overall visits dropped 5% in that period.

CDC has officially closed the investigation of e.coli outbreak in Chipotle restaurant. Now, the restaurant chain must work hard to win back its customers.