Listeria Outbreak Associated with Blue Bell Ice Cream
Blue Bell Creameries recently did product recall for the first time in their 108 years of company’s history caused by an outbreak of Listeria monocytogenes. There were in total 10 cases in 4 states & 3 deaths affected by the outbreak. They have 3 production facilities and all of them were contaminated with Lm: one in Texas (which is the headquarters), and two auxiliary production lines in Oklahoma and Alabama. In this post, I’m focusing on what happened in the Oklahoma facility.
The first 5 Listeriosis cases that were reported in Kansas early March 2015. They were all hospital inpatients and immunocompromised, and 3 of them actually died, which made up the total deaths for this outbreak. In late March 2015, using PFGE and Whole Genome Sequencing, Kansas Department of Health and Environment found out that the same strains of Lm found in the patients were traced back to unopened Blue Bell Creameries’ 3 oz. Institutional/Food Service Chocolate Ice Cream cups served in the hospital, which were manufactured in the Oklahoma production facility. Interestingly, this product was distributed to 23 states and only sold in schools, nursing homes, and hospitals, which mainly accomodate individuals at risk. This suggests that there were probably unreported cases of listeriosis linked to the Blue Bell Creameries’ products.
In May 7, 2015, the FDA released findings from Blue Bell Creameries’ production facility in Oklahoma. In this report, there are 12 observations being made but I’m only going to outline several points.
This report mentions that the Oklahoma Department of Agriculture, Food, and Forestry established a requirement of 20 CFU/mL of Lm or less in finished products of frozen dairy desserts. In March 2015, 275 CFU/mL Lm was found in the finished product half-gallon Dutch Chocolate Ice Cream, more than thirteen times the recommended levels. Now, if we assume that there is 275 CFU/mL of Lm in a 3 oz. (88mL) Institutional/Food Service Chocolate Ice Cream cup, then there is in total 24,200 CFU of Lm in one cup. However, several hospital patients fell ill after consuming the particular product, which means that the amount of Lm in that product is at least at an infectious dose of 0.1 to 10 million CFU for at risk individuals. Based on these assumptions, Lm might continue to grow under freezing temperatures, but more research needs to be done on this subject. Another possibility is that some finished products of the chocolate ice cream already had enough Lm in it to infect at risk individuals, therefore any more Lm growth would not make any impact.
This report also mentions that the plant’s production line is not designed to prevent cross-contamination from drippings and condensate from pipes and tank lids. The lids on top of the tanks containing post-pasteurized Dutch Chocolate Ice Cream were not closed tightly, hence condensate from another product line installed horizontally right above it drips into the tanks, which makes a potential source of Lm contamination. Additionally, a worker was observed spraying the top of the lids and switching lids between other post-pasteurized Dutch Chocolate Ice Cream tanks, which may contribute to Lm cross-contamination in the tanks. The rest of the report states that lack of employee hygiene and inadequate facilities for cleaning and sanitizing equipments might be some contributing factors to the growth of Lm in their products.
Now, if you were to be part of Blue Bell Creameries’ quality control team at the Oklahoma production facility, what would you do? What recommendations would you offer to make the production line safer?
cheryl lau, 
Mandy Tam, 
meggyli, and 6 others are discussing.
wen liao 9:19 am on October 26, 2015 Permalink |
It is definitely amazing how Listeria can survive and still being infectious in made ice-creams, considering it is an environment low in temperature and water activity. As we have discussed in class before, ice-cream is considered as one of the products where there should be no growth of Listeria what’s so ever. Thus the problem here definitely are due to the ingredients. Since ice cream production are considered as low Listeria risk, people work here might pay less attention on sampling and checking on listeria load, which might be the cause of the problem. Therefore, it is important that people working in food industry pay extreme attention on what they are doing to ensure food safety.
YaoWang 1:39 pm on October 27, 2015 Permalink |
We all know that Listeria is a main concern in ready to eat meat products, but it’s amazing to know that it can be a problem even in ice cream. Normally, since ice cream provides low temperature and low water activity, we assume there shouldn’t be Listeria present. I’m very curious about how listeria can survive and may even grow under such environment. But this recall reminds us that even though the food is of less possibility of certain microbial contamination, the manufacture must still follow proper handling techniques to avoid potential cross contamination.
amreenj 7:18 pm on October 28, 2015 Permalink |
Wow! As we have previously learned, ice cream is considered a Category 2B food, which is a ready to eat foods in which Listeria monocytogenes cannot grow. So the occurrence of Lm. in ice cream is surprising. Im interested to see if they can actually trace the source of the Lm. and report back their findings. The worse part is that it was given to individuals whose immunity is low (ie. high risk groups- longer term care facilities, hospitals) and thus the impact could have been so much worse. Having preparing sanitation and handling protocols is imperative to recurring the risk of food borne illnesses. As we can we that failing to do so can lead to contamination in even the most unlikely of places/foods!
mustafa akhtar 10:18 am on October 29, 2015 Permalink |
I am so surprised that they ONLY distributed this product to schools, nursing homes, and such. I wonder if any research was put into developing the product at all. If not, then atleast the product shouldn’t have been sent to places where immunocompromised people reside.
Susanna Ko 4:55 pm on October 29, 2015 Permalink |
I think it shows that people must be diligent when deciding on the food menu for certain populations such as elderly or immunocompromised. Also, it’s surprising that the company survived so far without failing an inspection. Was it because it was categorized as a low-risk food, meaning that it is inspected less frequently? Also, how many spontaneous abortions occurred from pregnant women consuming this product because they wanted to enjoy a special treat? It’s really unfortunate.
Stephanie Chen 6:00 pm on November 19, 2015 Permalink |
It is really quite sad that even a delicious treat such as ice cream can harbor foodborne pathogens, and with a company that must have had good reputation for so many decades. Bluebell also explained that the reason they did not test their ice cream after positive tests of Listeria in their plant in previous years was because Listeria was found on non-food surfaces that did not come in contact with ice cream products. It was also not required at the time to report Listeria findings to the FDA. This shows that practices in the industry need to be routinely evaluated and food safety regulations should be strictly enforced.
meggyli 10:11 pm on November 27, 2015 Permalink |
Another interesting class-related blog! We learned in class that ice cream belongs in a category 2B food where the chances of Listeria growth/contamination is really rare. Similar to the above caramel apple blog, this just goes to show that we can never be too careful. It always causes the most damage to our health and economy when it’s the most unexpected food that contracts a pathogen. Who would have thought that something like ice cream which inhibits most microbial growth due to its cold storage temperature could cause something as severe as stillbirths & spontaneous abortions.
Mandy Tam 9:02 pm on December 1, 2015 Permalink |
I think a lot of time when people think of outbreak in related to Listeria Monocytogenes are related to ready to eat meat or deli product. I think this article provides a great example that Listeria growth could happen in other foods as well.
North America very emphasis in HACCP and GMP in food plants but there are still many problems. I think what will help food plant to improve food safety in the future is to have a database approved by government agency where companies can share and excess information in regard of good plant design and HACCP program information in all food type. Therefore, it avoids problems caused by bad equipment design or inexperience HACCP team.
Anyhow, great article and it provides a lot of insight in term of Listeria Monocutogenes!
cheryl lau 3:19 pm on December 4, 2015 Permalink |
Very interesting article! I am also surprised that this is the first time that the company has recalled their products due to Listeria monocytogenes contamination from the conditions mentioned in the FDA report. Condensed water from pipes in food manufacturing is often a problem if not dealt with. These problems usually present over time, I am surprised that the plant allowed production to continue. Perhaps the quality control personnel should ensure that the workers realize the risk involved from contamination due to irregular working conditions. The workers could then report to the supervisor when the equipment is not functioning at the optimum level to prevent these outbreaks from happening.