Officials investigating a deadly outbreak in Austria have found Listeria at the company thought to be responsible.

Listeria isolates with the same genetic fingerprint as the outbreak strain were detected in three environmental samples from the firm in Lower Austria.

Käserei Gloggnitz previously recalled all kajmak, drinking yogurt and cream cheese products because of potential Listeria monocytogenes contamination. Kajmak is a type of cheese.

The Listeria strain behind the incident does not match any of those in the AGES Listeria database, which contains more than 15,000 sequences of human, food and environmental isolates.

Cluster analyzes by the Austrian Agency for Health and Food Safety (AGES) found eight infections occurred since 2020 because of an identical Listeria strain. Three people died between 2020 and 2022.

Illnesses occurred in Vienna. The patients are five women and three men aged between 29 and 82 years old.

The outbreak strain has also been detected in a food product from the suspected company. This food was served in a restaurant mentioned when the sick people were interviewed.

The Ministry of Social Affairs, Health, Care and Consumer Protection (BMSGPK) had asked AGES to investigate the outbreak.

AGES said local food authorities have taken “appropriate measures” to deal with the incident. These included temporarily stopping production at the site for steps including cleaning and disinfection ahead of a review before potential restart, according to local media.

about Listeria infections

Food contaminated with Listeria monocytogenes may not look or smell spoiled but can still cause serious and sometimes life-threatening infections. Anyone who has eaten any recalled product and developed symptoms of Listeria infection should seek medical treatment and tell their doctors about the possible Listeria exposure.

Also, anyone who has eaten any of the recalled products should monitor themselves for the food poisoning symptoms during the coming weeks because it can take up to 70 days after exposure to Listeria for symptoms of listeriosis to develop. 

Symptoms of Listeria infection can include vomiting, nausea, persistent fever, muscle aches, severe headache, and neck stiffness. Specific laboratory tests are required to diagnose Listeria infections, which can mimic other illnesses. 

Pregnant women, the elderly, young children, and people such as cancer patients who have weakened immune systems are particularly at risk of serious illnesses, life-threatening infections, and other complications. Although infected pregnant women may experience only mild, flu-like symptoms, their infections can lead to premature delivery, infection of the newborn, or even stillbirth.