On September 29, 2016, the CDC published their final update to the E. coli outbreak associated with General Mills flour. Although there may continue to be illnesses connected to contaminated flour, the investigation has been concluded, and the vast majority of illnesses have already taken place. In total, there were 63 people diagnosed with E. Coli poisoning as a result of eating products made with contaminated flour. Out of those sickened, 17 people needed to be hospitalized because of their illnesses. There was 1 reported case of hemolytic uremic syndrome, but there were no reports of death. People sickened in the outbreak reported that their illnesses began on dates ranging from December 21, 2015 to September 5, 2016. The CDC continues to warn consumers that because these products have a long shelf life, there is still the risk of people eating contaminated products. The CDC continued to recommend that the public dispose of all recalled flour.

            The outbreak was nationwide, affecting 24 different states. States impacted by the outbreak include Alabama with 1 case, Arkansas with 1 case, Arizona with 3 cases, California with 3 cases, Colorado with 4 cases, Iowa with 2 cases, Illinois with 4 cases, Indiana with 1 case, Massachusetts with 3 cases, Maryland with 1 case, Michigan with 4 cases, Minnesota with 7 cases, Missouri with 1 case, Montana with 2 cases, Nebraska with 1 case, New York with 4 cases, Oklahoma with 3 cases, Oregon with 1 case, Pennsylvania with 2 cases,  Tennessee with 1 case, Texas with 2 cases, Virginia with 3 cases, Washington with 5 cases, and Wisconsin with 4 cases.

            The investigation, led by the CDC as well as state and local health officials, uncovered that the cases of E. coli poisoning were the result of flour produced by General Mills. This was the result of epidemiologic, laboratory, and traceback evidence. Over the course of the investigation, the CDC conducted interviews with those who were sickened in the outbreak. In the interviews, 76% of people reported the use of flour in the weeks prior to their illness. 50% reported that they had tried raw dough in the weeks prior to their illness. 57% of people reported specifically using Gold Medal brand flour prior to their illness. Several of those sickened also reported playing with raw dough prior to their infection.

            The investigation then deciphered the kind of dough that people had reported exposure to. The investigation was able to conclude that all flour connected to the outbreak was produced over the span of a week in a General Mills facility. The flour was produced in the Kansas City facility in the month of November 2015. Gold Medal brand flour is among the products produced at that facility. The company distributed the products nationwide. In June 2016, the FDA, who had been cooperating in the investigation with the CDC, was able match E. coli strains found in the Kansas City facility with samples taken from ill people.  To do this, the FDA employed the tried and tested method of pulsed field gel electrophoresis. By running a sample of DNA through a gel template, the FDA was able to match the DNA fingerprints of the various samples.

            As the investigation progressed, it became apparent that several General Mills products needed to be recalled. On May 31, 2016, the first of several recalls was issued by General Mills. The first recall was for a limited number of products and lots, mostly from the Gold Medal brand of flour. This recall would be expanded twice more over the course of the investigation, on July 1 and July 25, 2016. Not only would additional production dates be added to the recall, but other products as well. The recall expansions are the result of the FDA testing in June 2016. The samples that tested positive for E. coli bacteria were not taken from products included in the original recall. The expanded recalls would also affect brand names including Signature Kitchens and Betty Crocker. A full list of recalled products and their identifying information can be found  here.

E. coli is a family of bacteria found in a wide variety of environments. Most E. coli strains are harmless to humans, and in fact many beneficial strains of E. coli live in the intestines of humans and other animals. Some E. coli, though, produce toxins that can cause illness in humans. The most common form of pathogenic E. coli is Shiga toxin-producing E. coli, or STEC. Shiga toxin-producing bacteria are the cause of the General Mills outbreak. These bacteria most commonly contaminate items such as beef, other meats, apple cider, raw milk, and cheese made with raw milk. E. coli bacteria can also contaminate fruits, vegetables, and water. E. coli infections are one of the most common forms of foodborne illness. The CDC estimates that around 265,000 E. coli infections occur each year in the United States. While E. coli infections can affect people from any age group and background, young children and the elderly are at an increased risk of developing a serious E. coli infection or even HUS.

When contaminated food exposes someone to pathogenic E. coli bacteria, they can expect to see symptoms within 3 or 4 days, on average. Sometimes the bacteria could produce symptoms as early as one day or as late as ten days after the initial exposure. Symptoms of E. coli poisoning can vary, but most develop vomiting, fever, stomach cramps, and diarrhea. Doctors may test to confirm the presence of E. coli, but in most cases the best treatment for E. coli is rest and hydration. In most cases, an E. coli infection will subside on its own within a week. However, some cases of E. coli infections can be life threatening. In about 5 to 10% of E. coli poisoning cases, a complication called hemolytic uremic syndrome (HUS) arises. HUS is a complication that damages red blood cells. These damaged cells undergo a filtration process when they pass through the kidneys. Filtering these HUS-affected blood cells and removing them from the bloodstream can cause damage to the kidneys, and could even lead to kidney failure. HUS can cause other symptoms, including decreased frequency of urination, loss of color in the eyes and cheeks, and fatigue. If you or a loved one begins to show the symptoms of E. coli poisoning or HUS, contact a medical professional.

Sources:

http://www.generalmills.com/flour

http://www.cdc.gov/ecoli/2016/o121-06-16/index.html

http://www.cdc.gov/ecoli/general/index.html