<P> On February 1, 2016, the CDC official closed their investigations on the larger E. coli that started in Pacific Northwest in October 2015 and also the smaller outbreak that started in Kansas and Oklahoma in November since no new cases were reported since December 1 . In their final report, the CDC stated that 55 persons in 11 states were infected with the same strain of STEC O26 during the major outbreak with 21 of those persons requiring hospitalization . The five persons infected in the later outbreak were made ill by a generically different strain of STEC O26 . The CDC also reported that federal and local health and food safety authorities were unable to detect traces of the microorganisms in any of the food samples taken from the suspected restaurants or from their supply chain . The CDC, FDA, and the USDA Food Safety and Inspection Service were unable to determine a point source that was in common in the meals that were consumed by all the victims since some of the restaurants were located far apart and had obtained some of their ingredients from different suppliers while other consumers of the suspected suppliers were not affected . </P> <P> The Centers for Disease Control and Prevention reported on December 21 that five more people became ill after eating at two Chipotle restaurants located in Kansas and Oklahoma in late November . Preliminary DNA fingerprinting results appear to indicated that the newer cases were caused by a different strain of Shiga toxin - producing E. coli O26 . Scientists are waiting for the results of the more definitive whole genome sequencing analyses to determine if the organisms responsible for this outbreak are genetically related to the E. coli that are responsible for causing the outbreak that had started in Oregon and Washington in late October and thus an extension of that outbreak . The agency has not yet determined which food is responsible for the outbreak . The Food and Drug Administration reported that they are trying to determine how the bacteria in these cases, along with the earlier Oregon, Washington, and other multi-state cases, might have been propagated through the food supply chain . </P> <P> In December 2015, eighty students at Boston College were sickened after eating at a single Chipotle restaurant . Affected students had been tested for both E. coli and norovirus in order to determine the cause of the illnesses . Although it would take as long as two days before the results of more definitive tests became known, public health investigators reported that preliminary tests pointed to the presence of norovirus . The health inspectors for the City of Boston had since closed this particular location on December 7 for a number of health violations that included maintaining meats at a too low of a temperature on the serving line and for allowing a sick employee to work at the time of the inspection . </P> <P> On December 10, officials from the Boston Public Health Commission reported that tests had identified a single strain of norovirus that is responsible for this particular outbreak . Boston Globe reported on December 10 that 141 persons were reported to have gotten ill and that some of the newer victims had not visited Chipotle before contracting the virus and most likely became infected by being in close proximity to someone who had gotten ill at Chipotle, such as a roommate or dorm - mate . Boston authorities traced the cause of the outbreak to a sick employee who was allowed to work on the day of the outbreak . Chipotle has since fired the employee and also the manager who knowingly allowed the ill worker to complete his shift instead of following health codes . </P>

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