As of April 21, 2015, a total of ten patients infected with several strains of Listeria monocytogenes were reported from four states: Arizona (1), Kansas (5), Oklahoma (1), and Texas (3). Illness onset dates ranged from January 2010 through January 2015. The patients with illness onsets ranging from 2010-2014 were identified through a retrospective review of the PulseNet database for DNA fingerprints that were similar to isolates collected from Blue Bell ice cream samples. Since the last update on April 8, 2015, two additional patients, one each from Arizona and Oklahoma, were confirmed to be a part of the outbreak by whole genome sequencing. All ten (100%) patients were hospitalized. Three deaths were reported from Kansas.
One additional isolate from a patient with listeriosis is undergoing further molecular laboratory testing to determine whether this illness may be related to this outbreak. Results of this testing will be reported once they are available. CDC and state and local public health partners are continuing laboratory surveillance through PulseNet to identify any other ill persons that may be part of this outbreak.
On April 20, 2015, Blue Bell Creameries voluntarily recalled all of its products currently on the market made at all of its facilities, including ice cream, frozen yogurt, sherbet, and frozen snacks, because they have the potential to be contaminated with Listeria monocytogenes. Blue Bell announced this recall after sampling by the company revealed that Chocolate Chip Cookie Dough Ice Cream half gallons produced on March 17, 2015 and March 27, 2015 contained the bacteria. Listeria monocytogenes was previously found in other Blue Bell products. CDC recommends that consumers do not eat any Blue Bell brand products, and that institutions and retailers do not serve or sell them.