Regis Pouillot, DVM, PhD, the contact for the team, noted that since all of the cases in the study occurred in the same hospital, it was impossible to fully rule out a growth of the bacteria on a milkshake machine or some kind of “systematic issue” that might have increased dosage levels between the time the ice cream left the containers and the time that the milkshakes were consumed. However, the “takeaway” lesson from the study remains that individuals with weakened immune systems are at the most risk of infection by listeriosis contamination in food products and, as a result, there is a need for further development of effective risk management to prevent and mitigate infections.
A CDC spokesperson added that risk management of patients with elevated risk of contracting invasive Listeriosis who may have consumed contaminated food products often must be made “on a case-by-case basis, informed by clinical judgment and the likelihood of exposure of the patient” since many patients present few or no symptoms but consult a physician as a result of consuming a recalled product. However, familiarity with mild symptoms other than diarrhea and fever such as headache, stiff neck, and loss of balance that tend to affect older adults and immunocompromised individuals who may not display other symptoms will aid physicians in making a diagnosis and determining the best treatment moving forward. Patients who develop symptoms within two months of eating the recalled product should return for medical treatment, she added.
Karl C. Klontz, MD, physician and epidemiologist at the FDA, recommended that the medical community continue to educate their patients about making proper food choices, especially for those at highest risk of infection. “The truth is less people are becoming infected rates of listeriosis (that is, number of cases per 100,000 population per year; see chart
) have decreased substantially over the past 16 years,” he said. “For that, we can credit sound education and a better oversight of the nation’s food supply.”
Chart: Number of Cases of Listeriosis Per 100,000 Population Per Year
Data Source: FoodNet
To stay informed on the latest in infectious disease news and developments, please sign up for our weekly newsletter.