Blue Bell ice cream is being linked to 3 deaths and 2 other illnesses that occurred in one Kansas hospital and over the course of one year. The patients were not hopitalized for Listeria but came into contact it while there at the hospital. All were older patients. While the patients were infected with one of four strains, 3 of the strains have been found in product samples by South Carolina Dept of Health during routine testing. After investigating the facility, Texas Department of Health collected samples from the manufacturing facility and found the organisms in the same products.
A later news report stated that officials said that Listeria may be a factor and that four of the five ate milkshakes made with the ice cream. Interesting.
So a few things to note.
1) To date, this is the only setting that had an outbreak. Why one hospital?
2) Was product handled by the hospital? It would appear so that milkshakes were made from the ice cream.
So while it is yet to be determined, if you had to guess, could it be that indeed the Listeria was present in the ice cream, but the fact that milkshakes were served, could indicate that though handling and preparation, the organism was able to grow to a higher level within the milkshake during preparation and handling. Could it be that the patients left the milkshake warm up before eating, or ate it over the period of a day. So this served as amplification step? Perhaps this is why we didn't see any cases associated with frozen treats? You are not going to eat them after they melted. Of course this is all hard to tell based upon the limited information provided in the news reports.