The current Listeria monocytogenes outbreak identified by the Centers for Disease Control and Prevention (CDC) that has no identified source has been going on since 2017. Looking back through our archives, we have found that this is not an isolated incident. Why are Listeria illness onset dates spread out over years?
Listeria monocytogenes is a dangerous pathogen. When people in certain categories, including people with compromised immune systems, chronic illnesses, the elderly, and pregnant women, contract this infection, many people get seriously ill. Most, if not all, of those sickened with listeriosis end up in the hospital. And the mortality rate for patients in these groups can be as high as 20-30%.
In the Listeria outback linked to unnamed deli meats and cheeses, which has not ended, eight people were sickened. All were hospitalized and one died. The illness onset dates ranged from November 2016 through early 2019. And in the outbreak associated with CRF Frozen Foods, illnesses were first identified in March 2016, but patients were eventually found who got sick from September 2013 to May 2016.
And in the Blue Bell ice cream Listeria monocytogenes outbreak that was identified in late 2014, illness onset dates ranged from 2010 through January 2015. The investigation into that outbreak revealed a longstanding issue with contamination at the Blue Bell company’s Texas and Oklahoma plants.
This long time frame in illness onset dates can be explained in several ways. First of all, cases are sporadic. Not everyone who eats food contaminated with Listeria monocytogenes bacteria gets sick, because people who are sickened by this pathogen usually have other serious health conditions. Healthy adults rarely contract this infection.
Then, the contamination may not be widespread in a food. Some bacteria could cluster in small clumps, so not every piece of food in a package is contaminated. Finally, Listeria monocytogenes can be very difficult to eradicate once it is established in a facility. Contamination may not occur with every product produced in that venue, but contamination may occur sporadically.
If you or a loved one has been diagnosed with a Listeria monocytogenes infection, you can contact attorney Fred Pritzker for help by calling 1-888-377-8900.
The long illness onset date range can also be explained in how cases are diagnosed. If one person gets sick after eating contaminated food, and they go to a doctor and are diagnosed, their illness is reported to the government, and the isolate is banked in PulseNet, the nationwide network of public health labs. If no other isolates with the same DNA are found in the system, no outbreak is declared.
But if others are eventually diagnosed through the months and years after the first diagnosis, an outbreak is declared. It can then take time to identify a possible source; officials must interview patients and their families and conduct traceback and epidemiologic investigations. That takes time too.
To protect yourself and your family against listeriosis, there are some things you can do. If you have a person who is in a high risk category in your family, avoid purchasing deli meats and cheeses, ready-to-eat foods such as hot dogs and soft cheeses, and raw milk and its products. Always heat foods to a safe final internal temperature, and measure the temperature with a food thermometer. Finally, stay aware of recalls and outbreak notices.
And know the symptoms of this illness so you know when to call a doctor. Symptoms vary, but most people suffer severe headache, stiff neck, muscle aches, confusion, nausea, and diarrhea. Pregnant women suffer different symptoms, which may seem like a mild case of the flu. But listeriosis can cause miscarriage and stillbirth.
