Denmark reported 199 cases of invasive Listeria infection between 2023 and 2025 according to data from the Statens Serum Institut.
Only four of ten recent Listeria outbreaks were solved in Denmark
The average annual incidence was 1.1 cases per 100,000 inhabitants with yearly case counts ranging from 54 to 84.
Listeria poses serious risks to vulnerable populations in Denmark
Invasive listeriosis primarily affects individuals with weakened immune systems due to conditions such as cancer, blood disorders, kidney disease, diabetes, advanced age, or pregnancy.
Most Listeria cases in Denmark occurred in people over 65 years aged
Eighty-two percent of cases were in individuals over 65 and 56 percent were women during the 2023-2025 period.
Listeria bacteria can persist in food production environments for extended periods
This persistence can lead to outbreaks affecting multiple patients quickly or cause long-term sporadic cases over several years.
Listeria was detected in blood cultures for most Danish cases
Seventy-eight percent of infections were identified through blood cultures while 20 percent were found in cerebrospinal fluid and 2 percent in other specimen types such as placenta.
Nine Listeria cases were recorded among pregnant women in Denmark from 2023 to 2025
Infections in pregnant individuals and their newborns are recorded as a single case attributed to the mother with one to five cases reported annually.
What is invasive Listeria infection?
Invasive listeriosis is a serious foodborne infection caused by Listeria monocytogenes that can lead to bacteremia or meningitis.
Who is most at risk for severe Listeria illness in Denmark?
People with weakened immune systems from illness or treatment, older adults, and pregnant women are at highest risk for invasive disease.